Unified Monthly Employer Report (JMHZ) from 2026: How to Prepare and Avoid Fines

Ing. Veronika Sečková
Ing. Veronika Sečková
31.5.2026 | ARROWS law firm

The Unified Monthly Employer Report will change the rules of the game from 2026 – it introduces a single comprehensive monthly report instead of many forms, but also stricter record-keeping, new registers, and high fines for errors. In this article, you will find a practical guide on how to prepare for JMHZ and how to minimize the risk of penalties from the Czech Social Security Administration.

The photograph shows a specialist addressing the issue of the unified monthly employer reporting.

  • The Single Monthly Employer Report (JMHZ) is a new system of mandatory electronic reporting which, from 2026, replaces dozens of existing returns to the Czech Social Security Administration (ČSSZ), the Financial Administration, the Labour Office and other institutions with a single monthly filing.
  • The JMHZ obligation applies to all employers regardless of size, including those who pay even a single remuneration from dependent activity (e.g., to members of the bodies of an owners’ association (SVJ), executive directors, or temporary workers under DPP/DPČ), including in months when they in fact pay no wages at all.
  • The new regime brings stricter registration of employees and their employment relationships, an obligation to register employees (especially foreign nationals) before they start work, and electronic filing exclusively in a defined structure; technical or formal defects may result in the report being disregarded altogether.
  • Failure to file the JMH or to comply with registration obligations may result in fines of up to CZK 5,000 per employee and up to CZK 100,000 for breaches of registration obligations, and the sanctions may be very significant for a company in aggregate.

What the Single Monthly Employer Report is and why the state is introducing it

The Single Monthly Employer Report is a legal and IT framework that enables an employer to fulfil, vis-à-vis several public authorities (the Czech Social Security Administration (ČSSZ), the Ministry of Labour and Social Affairs, the Financial Administration, the Labour Office, the Czech Statistical Office, etc.), most of the existing notification obligations through a single electronic filing. The key legislation is Act No. 323/2025 Coll., on the Single Monthly Employer Report, which took effect on 1 January 2026 and gradually replaces the existing system of many separate forms.

The aim is to standardise data, reduce duplication and enable more efficient sharing and processing within public administration, not merely to “move” paper forms into electronic form.

In practice, this means that data which the employer previously reported separately, for example in the monthly statement of social security insurance contributions, in pension insurance record sheets, in annual settlements of tax on income from dependent activity, or in certain reports for the Labour Office and the Czech Statistical Office, will to a large extent be included in one data message – the Single Monthly Report (JMH). The JMH is, however, only one of the processes within the overall JMHZ system; the system also includes electronic registration of employers and employees, including their employment relationships and other labour-law relationships.

The state argues that, in the long term, JMHZ will reduce the administrative burden for employers because it will eliminate the need to send in parallel up to 25 different forms to different authorities with different deadlines and often overlapping data. In the short term, however, the reality is more complex: companies must fundamentally redesign their payroll and HR processes, implement payroll software updates, add a range of new employee data, and ensure flawless operation of the new electronic reporting. This is also why the introduction of JMHZ is accompanied by a transitional period and a so-called hybrid regime, in which certain obligations are gradually “shifted” from the original agendas into the new system.

It is important to realise that JMHZ is not merely a “technical project of the social security authority”, but has major tax, employment-law and statistical impacts under Czech law. Detailed monthly data at the individual level is, for example, intended to enable the Financial Administration in the future to provide pre-filled annual tax returns and annual tax settlements for employees. From the employer’s perspective, however, it also means that any errors in payroll and tax data may more quickly translate into inspections by both the Financial Administration and the Czech Social Security Administration (ČSSZ) and worsen the company’s position when defending against additional assessments or fines.

For practice, it is therefore essential to understand JMHZ not as a one-off task of “introducing a new form”, but as a complex infrastructure change that requires parallel adjustments to internal processes, IT systems, documentation and often also employment contracts or agreements. Attorneys from ARROWS advokátní kancelář, a Prague-based law firm, repeatedly see in practice that companies which underestimate this change and leave it “only to payroll accounting” expose themselves not only to the risk of fines from the Czech Social Security Administration (ČSSZ), but also to non-compliance with tax and employment-law regulations, which may later result in court disputes or transaction delays during due diligence.

Who is required to file JMHZ and whom you must register

One of the most significant changes is the breadth of the range of entities to which JMHZ applies. The JMHZ Act expressly provides that the obligation to file the Single Monthly Report applies to all employers regardless of their legal form or size—i.e., business corporations, self-employed individuals, municipalities, associations, foundations, schools, owners’ associations (SVJ) and other entities—provided they meet the definition of an employer under Section 3 of the JMHZ Act.

In practical terms, this means the obligation applies to anyone who is a payer of personal income tax from dependent activity, even if they have only one employee or pay remuneration only once a year.

Likewise, the definition of “employee” is significantly expanded. For JMHZ purposes, this means not only an employee under the Labour Code or under social security regulations, but any taxpayer of personal income tax from dependent activity under Section 6 of the Income Taxes Act. This includes, for example, executive directors receiving remuneration, members of statutory and supervisory bodies of business corporations, shareholders receiving remuneration for work performed for the company, persons working under agreements to perform work (DPP) and agreements on work activity (DPČ) (including without participation in insurance), certain elected officials of municipalities and regions, and other persons who receive taxable income from dependent activity.

From the JMHZ perspective, the decisive factor is whether it is income from dependent activity, not the form of the contract or whether the employee reaches the decisive income threshold for participation in sickness insurance. For example, for agreements on work activity (DPČ), the decisive amount for participation in sickness insurance in 2026 is set at CZK 4,500 per month; however, for JMHZ purposes you must register and report even DPČ arrangements that do not reach this threshold. Similarly, for agreements to perform work (DPP), the decisive income for participation in insurance in 2026 is newly CZK 12,000 per month; however, for JMHZ you also report “uninsured” DPP arrangements with lower income, provided it is income from dependent activity.

By contrast, employees for JMHZ purposes do not include persons who have income from independent activity under Section 7 of the Income Taxes Act, typically self-employed contractors invoicing under a contract for work or an author’s contract, unless it is a disguised employment relationship. You therefore do not report authors’ fees or business remuneration in JMHZ, even though they may be reflected in other tax or statistical agendas.

A specific group includes individuals receiving exempt income from dependent activity – for example, certain non-cash benefits or other benefits that are exempt from income tax but still have the nature of income from dependent activity. The Act on JMHZ expressly provides that these individuals are also regarded as employees and must be included in the employee register, because what matters is the nature of the income as income from dependent activity, not whether it is taxed. For 2026, however, the Financial Administration has allowed certain temporary simplifications – for example, it will not require the reporting of certain exempt income for individuals who are no longer employees in the given month and have no other income from dependent activity, which is significant, for example, for former employees receiving subsidised meals.

In practice, this means that many entities that have not previously been accustomed to acting as “employers” vis-à-vis the Czech Social Security Administration (ČSSZ) will newly fall under the JMHZ regime. Typical examples include owners’ associations (SVJ) paying remuneration to members of the executive committee, small family companies with a single managing director receiving remuneration, or self-employed individuals who hire occasional temporary workers under agreements. If you are registered with the Financial Administration as a payer of tax on income from dependent activity, you will generally also be considered an employer for JMHZ purposes, and you will have a registration obligation and subsequent monthly reporting obligations.

From a risk management perspective, the first step is therefore to carry out a careful screening of all relationships in which income from dependent activity may arise. In practice, the attorneys from ARROWS, a Prague-based law firm, often identify “hidden employees”, typically members of corporate bodies or individuals working for a group of companies under various contracts, which have so far been ignored from a social security perspective. In the context of JMHZ, such “blind spots” may lead not only to additional assessments of insurance contributions, but now also to fines for missed registration and for failing to file JMH for specific individuals.

Most common questions on the obligation to file JMHZ

1. We are a small company with one managing director who receives remuneration – do we have to register as an employer because of JMHZ?
Yes, if the managing director’s remuneration is taxed as income from dependent activity under Section 6 of the Income Taxes Act, you are a payer of tax on income from dependent activity and, for JMHZ purposes, you are considered an employer with all related obligations. In such a case, it is advisable to set up proper records and processes with the help of the attorneys from ARROWS, a Prague-based law firm, to avoid penalties for late registration or failure to file the report.

2. We occasionally hire temporary workers under a DPP below the threshold for social insurance – do we have to report them in JMHZ from 2026?
Yes, for JMHZ it is not decisive whether the person participates in sickness insurance, but whether it is income from dependent activity; all DPP and DPČ arrangements, including “uninsured” ones, must be recorded and reported for each month in which the relationship exists, even if no remuneration is paid. The attorneys from ARROWS, a Prague-based law firm, can help you incorporate the correct set-up of records for these short-term relationships into internal policies and payroll software.

3. We are a purely investment holding company with no employees, but we have members of corporate bodies receiving remuneration in subsidiaries – does JMHZ apply to us?
The decisive factor is whether the given entity pays income from dependent activity; if the holding company itself does not pay any such income, the JMHZ obligation usually does not apply to it, but it may apply to individual subsidiaries. In complex holding structures, it is advisable to carry out a legal and tax analysis with the team at ARROWS, a Prague-based law firm, to clarify which entities have registration and reporting obligations and to prevent the risk of sanctions within the group.

Timeline of changes and the transitional period in 2026

The Act on the unified monthly employer report becomes effective on 1 January 2026; however, regular monthly reporting begins only from April 2026. The first proper unified monthly report is filed for April within the deadline from 1 to 20 May 2026, and filing earlier than the first day of the following month is legally ineffective.

At the same time, for January, February and March 2026, employers must file JMH retroactively in the period from 1 April to 30 June 2026, separately for each month.

From a practical perspective, the period from 1 January to 31 March 2026 is viewed as transitional. During this time, employers do not yet file JMH, but they must already keep the required records to the extent required by the new act so that they can subsequently compile unified monthly reports for these three months. This means, in particular, careful record-keeping of data on all employees, including those who have not previously been in the ČSSZ register (e.g., uninsured agreements, managing directors with low remuneration), data on their employment relationships, income, assessment bases and other parameters that will later be subject to electronic reporting.

At the same time, the structure of obligations in the area of insurance contributions is also changing: from 2026, employers will no longer submit the classic “Statement of the amount of insurance contributions” for social security, because insurance contribution data will now be part of the unified monthly report. However, insurance contributions remain payable within the same deadline as before, i.e., by the 20th day of the calendar month following the month for which the contributions are paid. In practice, this means that in the first quarter of 2026, contributions are paid but statements are not filed, whereas from April 2026, contributions are paid and, at the same time, the data on them are reported in JMH.

A very important part of the transitional period is also the so-called supplementary registration of data on employers and employees. All employers already listed in the ČSSZ employer register are “taken over” into the register under the JMHZ Act, but they are required, in the period from 1 to 30 April 2026, to supplement missing data by filing “Employer registration – Supplementary filing” (REGZEL _DOPL). This mainly concerns data that ČSSZ has not recorded to date but is newly needed for JMHZ, for example certain identification and tax information for the Financial Administration.

A similar supplementary registration also applies to employees. By the end of April 2026, the employer must report, via the “Employee registration” filing (REGZEC – Change action), data on all employees who are not yet in the ČSSZ register, or for whom some newly required data is missing (e.g., tax residency). According to available information from ČSSZ, for example, tax residency data is missing for approximately one fifth of registered employees, and its absence may lead to JMH being rejected as incomplete. This is a typical example of a technical detail that can create a very specific risk for businesses – a JMH filed on time may become ineffective due to a formal defect, and the employer will be in default and exposed to a fine.

A non-negligible role is also played by the schedule for tightening record-keeping obligations during 2026. From 1 April 2026, the registration of new employees, especially foreign employees, is moved fully into the JMHZ system, and employers are required, for foreign nationals, to complete registration via REGZEC in full scope no later than the day before the commencement of work. From 1 July 2026, a similar regime, with the possibility of simpler pre-registration, is extended to Czech employees as well, which in practice ends the previous “comfort” of the eight-day deadline for registering an employee after they start work.

From a company management perspective, it is therefore crucial to keep three things under control: whether all supplementary registrations of the employer and employees have been completed on time, whether from April 2026 all employments are recorded under the new regime, including short-term and “non-insured” relationships, and whether internal deadlines and control mechanisms are set so that no JMH is forgotten or submitted with a technical defect. Attorneys from ARROWS, a Prague-based law firm, often help clients set up an internal “JMHZ calendar” and review employment and HR processes so that the legislative timeline is reflected in a realistically manageable workflow.

How to register: employer, payroll office and employees

The register of employers under the JMHZ Act is a central register containing key data on each entity considered an employer and on its payroll offices. Filings relating to an employer’s registration in the register of employers may be made only electronically, via an e-filing in PDF format sent to the data box of the Czech Social Security Administration (ČSSZ) or via the ČSSZ ePortal. Changes and deregistration, by contrast, are submitted in XML format.

Existing employers who are already entered in the register of employers under sickness insurance regulations are transferred to the new register, but must supplement missing data by the end of April 2026 by means of a one-off filing REGZEL _DOPL. This supplementary registration is key—without it, it will not be possible to file JMH properly, and if the employer fails to comply, it faces the risk of a fine of up to CZK 100,000 for breach of the registration obligation.

For newly established employers, different deadlines apply from 2026 depending on when the first employee starts. In general, as soon as an employer begins its activity and becomes an employer under the JMHZ Act, it must register in the register of employers no later than two working days before the first employee starts work, but no earlier than fifteen days before that date; at the same time, it must also register all payroll offices. 

However, transitional provisions allow an employer whose first employee starts only after 1 April 2026 to fulfil the registration obligation within 8 days of commencement, but only for a limited period. For a foreign employee, the situation is stricter—the employer must register in the register before the moment the employee starts.

For larger groups, it is important to take into account that each entity registers separately—it is not possible to register a “group” of employers under one identifier. In practice, this means that a holding structure with several companies must carry out registration (or supplementary registration) for each company that pays income from dependent activity. Attorneys from ARROWS, a Prague-based law firm, typically recommend centralising the preparation of registration filings in such situations and, at the same time, harmonising internal data on payroll offices to avoid duplications or errors in variable symbols and other identifiers.

Employee register – registration, changes and deregistration

The employee register under the JMHZ Act contains data on all employees within the broad definition under the Act, i.e., all persons who may receive income from dependent activity regardless of participation in insurance or the legal form of the relationship. Filings relating to an employee’s registration (registration, change, deregistration) may again be made only electronically via a data box, the ČSSZ ePortal, or the data interface (APEP/VREP).

The employer is obliged to register a new employee in the employee register within 8 days from the day on which one of the decisive facts occurred, typically the start of employment or the creation of an obligation to provide benefits, or the day on which it submitted an application for sickness insurance benefits before registering the employee. For foreign employees (persons other than Czech nationals), however, a stricter regime applies—they must be registered no later than before the moment they start employment, and in full scope, i.e., with all data required by law.

From 1 July 2026, a similar obligation to register an employee before they start work will also be extended to Czech citizens, while the Act allows a two-step procedure—before the actual start, a simplified pre-registration with a limited scope of data can be made, and the remaining data can be completed within 8 days of commencement. If a pre-registered employee ultimately does not start, the registration must be cancelled within 8 days from the expected start date.

As soon as there is a change in the recorded data about an employee (e.g., change of address, type of employment relationship, scope of working hours, health insurance company, etc.), the employer is obliged to report this change within 8 days from the day it learned of it. After the end of employment, the employer must deregister the employee from the register again within 8 days, either as of the date the employment ends, the date the obligation to provide benefits ends, or the date on which it in fact ceased providing the benefits.

A substantial qualitative shift is that the employee register works not only with the person of the employee, but with each individual employment, which is uniquely identified by the so-called employment identifier (employment ID, ID PPV). In addition, the employee receives a new personal identification number (OIČ), which will accompany them across all social security agendas. In practice, this means that for an employee with an employment contract and a concurrent DPP with the same employer, two separate employments arise, each with its own ID, and both must be recorded and reported in JMH.

Especially for so-called consecutive employments of the same type, the procedure changes from 1 April 2026. Until now, it was not necessary to report termination and a new start if it concerned consecutive insured relationships without interruption of insurance participation, for example when one employment relationship followed another. Under the JMHZ regime, however, each employment must be reported separately, and therefore even for consecutive relationships it is necessary to submit a filing on the termination of the original employment and the commencement of the new one, even though from the perspective of sickness insurance the participation may continue uninterrupted. This detail is often overlooked in practice and may lead to inconsistencies between the register and JMH.

For businesses, this means a fundamental demand for the quality and consistency of HR data. An incorrect combination of OIČ, employment ID and other identifiers, failure to complete mandatory fields, or entering incorrect code-list values may lead to the ČSSZ rejecting the filing as technically defective. Attorneys and tax advisers from ARROWS, a Prague-based law firm, therefore recommend that clients handle employee registration and work with the new identifiers in close cooperation between payroll, HR and IT, ideally based on an employee overview downloaded from the ČSSZ ePortal and subsequently reconciled with internal HR records.

Most common questions on registering the employer and employees

1. We already have employer registration with the ČSSZ—do we have to file a new application from 2026?
No, the existing registration is transferred automatically to the register under the JMHZ Act, but by the end of April 2026 you must submit the supplementary filing REGZEL _DOPL and complete the missing data; otherwise you risk that it will not be possible to file JMH on time and correctly. Attorneys from ARROWS, a Prague-based law firm, can assist you with preparing this filing in cooperation with your payroll department.

2. How should we proceed with foreign employees who start after 1 April 2026?
You must register foreign nationals via REGZEC in full no later than the day before they start performing work; the data include, for example, the travel document number, residence permit, or details of the type of residence authorisation. Given the strict regime and the risk of fines for illegal work, it is advisable to set up the foreign recruitment process in cooperation with the attorneys of ARROWS, a Prague-based law firm, who can align immigration, employment and JMHZ requirements.

3. What if an employee we pre-registered ultimately does not start on the planned date?
In that case, you are obliged to cancel the registration within 8 days of the expected start date; otherwise, the records will contain inaccurate data and may conflict with JMH or other agendas. It is therefore advisable to set internal HR and recruitment processes so that the payroll department is also informed of these situations, which the attorneys of ARROWS, a Prague-based law firm, can help you with by updating internal policies and work procedures.

The monthly report itself: content, deadlines and technical requirements

The Unified Monthly Report (JMH) is the core of the JMHZ system. It is an electronic filing in the form of a so-called data message, which the employer sends to the Czech Social Security Administration (ČSSZ) for each calendar month within the statutory deadline from the 1st to the 20th day of the following calendar month. A filing made before the first day of the deadline, i.e., before the first day of the following month, is considered technically defective and legally ineffective, as if it had not been filed.

The filing can be made exclusively electronically – via the ČSSZ data box, by uploading an XML file to the ČSSZ ePortal, by completing an online form on the ePortal, or via an API interface from payroll software.

The structure of the JMH is divided into three parts, which are also assessed separately in terms of defects: the summary part, the insurance part and the individualised part. The summary part contains data about the employer, including aggregate data for the Financial Administration (e.g., total payroll tax liability) and for other institutions. The insurance part includes data related to the amount of social security contributions, assessment bases and any contribution discounts.

The individualised part is the most extensive – it contains detailed data for each employee and each employment separately, including data for pension, sickness and tax purposes as well as statistical data (e.g., highest level of education attained). The scope of mandatory data is very broad and in practice corresponds to the content of payroll records plus additional supplementary information. In practice, this means that the company’s payroll system must be able to record these data in a structured way and export them in the prescribed structure.

From a deadline perspective, it is essential that the JMH is filed for each calendar month in which the employer was an employer, i.e., when it employed at least one employee within the meaning of the JMHZ Act. The filing obligation also arises for months in which no wages or remuneration were paid to any employee, but the employment continued – in such a case, a so-called “zero” report is filed for the given employee. Likewise, an employer who is a payer of payroll tax must file the JMH even in months without actual activity, if it is still registered as an employer.

Technically, the JMH relies heavily on the correct use of the OIČ and employment ID identifiers. If these identifiers are set incorrectly in the payroll system or are missing, the XML file may be rejected by the automatic validation of the ČSSZ ePortal. Common errors also include failing to complete mandatory fields, using invalid code-list values, or attempting to upload a file via the wrong ePortal service (e.g., via the “Forms” section instead of the “Submission by uploading data from the accounting system” service). These errors constitute technical defects, and therefore the relevant JMH is treated as if it had not been filed at all.

The JMH can be corrected by means of a so-called corrective report. A corrective report may be filed based on a request from ČSSZ, a notification from another data user (e.g., the Financial Administration), or on the employer’s own initiative, including after the statutory deadline for filing the JMH has expired. A corrective report may consist of supplementing missing data as well as changing previously reported data. 

The general time limit for filing a corrective report for a given month is up to 10 years, reflecting the long limitation periods in the area of contributions and pension entitlements. However, it should be taken into account that, for example, the amount of the employer’s contribution discount claimed for a specific month cannot be increased retroactively after the contribution due date – corrections are only possible “downwards”.

From a management perspective, it is important to set internal processes so that the JMH is filed on time even if some partial data have not been finalised in detail. ČSSZ itself recommends that in situations where employers cannot complete all data in time, they should file the JMH in a basic scope and subsequently use corrective filings, because a late filing as a whole may lead to sanctions, whereas partial corrections made within the proper time limit usually do not trigger the sanctions regime.

 In practice, the attorneys of ARROWS, a Prague-based law firm, often help clients set up an internal “two-step” process: a first deadline for internal closing of payroll data and a second, safety deadline for review and submission of the JMH within the statutory time limit.

Fines and sanctions from ČSSZ: typical situations and the level of risk

The JMHZ Act contains its own sanctions regime, which applies both to breaches of obligations in the area of employer and employee registration and to the obligation to file the Unified Monthly Report on time, in full and without serious defects. The amount of fines is not, at first glance, extreme, but in aggregate it may represent a significant financial burden, especially for larger employers or in cases of repeated breaches of obligations.

For failing to file the JMH at all, or for failing to respond to a ČSSZ request to remedy defects or supplement missing data, a fine of up to CZK 5,000 may be imposed for each employee for whom the report should have been filed. This means that for an employer with 100 employees, in an extreme case the fine may amount to up to CZK 500,000 for a single report that was not filed or remained uncorrected. In practice, ČSSZ takes into account the seriousness and circumstances of the case and may not always impose the maximum sanction; however, a stricter approach can be expected in cases of repeated or intentional breaches.

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For breaches of registration obligations – for example, late registration of the employer in the register of employers, late registration of an employee, or late reporting of changes to recorded data – ČSSZ may impose a fine of up to CZK 100,000. Particularly risky in this respect are situations where the employer does not register an employee before they start work, which from 1 April 2026 primarily concerns foreign nationals and from 1 July 2026 will gradually apply to all employees. These cases may be assessed not only as a breach of the JMHZ Act, but also as potential illegal work under the Employment Act, where sanctions are an order of magnitude higher.

In addition to direct fines, it is also necessary to consider the indirect impacts of a defective or missing JMH. If the JMH contains a technical defect (for example, it is filed before the start of the deadline, in an incorrect format, with errors in the data structure, or in another way that prevents automated processing), it is treated as if it had not been filed at all. In such a case, ČSSZ informs the employer that the filing is ineffective and calls on it to remedy the situation within 8 days. If the employer then fails to submit a replacement report in time, it falls into default with all related sanction consequences – including potential fines and disruption of employees’ entitlements to social security benefits.

With formal defects (i.e., errors in the content or structure of data that do not prevent automated processing), it depends on which part of the JMH the defect occurs in. If the error is in the summary section, only that section is ineffective; the same applies to the insurance and individualized section for a specific employee. 

However, if formal defects occur in all three sections and for all employees, the report as a whole is ineffective. After the deadline for filing the JMH has passed, the Czech Social Security Administration (ČSSZ) will call on the employer either to submit the report if it was not filed at all or is ineffective as a whole, or to correct it if it was accepted only partially; in both cases, the time limit to remedy the issue is only 8 days.

It should also be emphasized that a defective or missing JMH may have a direct negative impact on employees. Incorrectly reported assessment bases or insurance periods may lead to problems when granting sickness insurance benefits or a pension, or to inaccuracies in the annual tax reconciliation or when applying insurance premium discounts, for example for working pensioners. This increases the risk of employee complaints, reputational damage and, in extreme cases, disputes between the employer and employees over compensation for damage.

Attorneys from ARROWS, a Prague-based law firm, encounter in practice situations where an apparently minor error in the JMH led to delays in benefit payments or to the rejection of an employee’s pension application, which subsequently resulted in pressure on the employer and a claim for compensation for harm. In such cases, it is important not only to correct the defective JMH, but also to communicate with the ČSSZ and the employee, and, where appropriate, to defend against disproportionate sanctions.

Possible issues

How ARROWS helps (office@arws.cz)

Missing the deadline for filing the JMH : late or completely omitted JMH for a specific month, risk of a fine of up to CZK 5,000 for each employee

Analysis of the facts and sanction risks : we will prepare a legal strategy, file additional and corrective reports, represent you in proceedings before the ČSSZ and in negotiations to reduce or cancel the fine.

Defective registration of the employer or employees : missing additional registration, late registration or deregistration, incorrect data in the records

Setting up and reviewing registration processes : we will review your records, prepare the necessary REGZEL/REGZEC filings, and set internal policies and procedures so that errors do not recur.

Technical or formal defects in the data message : non-compliant XML structure, missing mandatory data, mismatch of OIČ and employment ID identifiers

Coordination of IT, payroll and legal : in cooperation with your payroll software provider, we will verify compliance with the JMHZ methodology, prepare testing scenarios and internal control mechanisms before submitting the JMH.

Risk of illegal work involving foreign nationals : late registration of a foreign employee, mismatch of the JMHZ with the residence permit and work authorization

Comprehensive immigration, employment and tax advice : we will align your recruitment process with obligations under the Employment Act, immigration law and the JMHZ, and represent you during inspections by the Labour Inspectorate and the ČSSZ.

Disputes with employees due to the impacts of errors in the JMH : objections to incorrectly reported insurance periods, benefits or insurance premium discounts

Dispute resolution and prevention : we will assess the validity of employees’ claims, propose amicable solutions or represent you in court proceedings; at the same time, we will set up internal JMH controls to prevent similar disputes.

How to prepare for the JMHZ in practice within your company

Implementing the JMHZ is not just “a task for the payroll accountant”, but a project that affects HR, finance, IT and the legal department. Companies that approach the JMHZ purely as a technical implementation of a new XML export in the payroll system often underestimate the legal and process impacts and subsequently face a series of requests from the ČSSZ, inefficient data tracing, and pressure from employees due to benefit-related issues.

The first step should be a systematic audit of data and processes. It is necessary to verify that all data required by the JMHZ exist in internal records and are up to date – from basic identification data of employees and the employer, through data on the type and nature of employment relationships, to tax residency, highest level of education attained and other statistical parameters. 

In many companies, it becomes apparent that some data have not been tracked at all so far or are kept only in paper form, which is unsustainable for regular electronic reporting. Attorneys from ARROWS, a Prague-based law firm, often propose expanding employment contracts and employee questionnaires to include missing information (e.g., tax residency, education) so that its collection is legally compliant and at the same time practically usable for the JMHZ.

The second pillar is cooperation with the payroll and HR software provider. The JMHZ places high demands on data structure and validation, which requires not only technical implementation of new data messages, but also adjustments to the user interface and control mechanisms. 

It is not enough for the software to be able to generate XML – it must also prevent the most common errors (e.g., missing mandatory fields, invalid code lists, mismatch of identifiers) and enable logical continuity between employee records and the JMH. Attorneys from ARROWS, a Prague-based law firm, can help at this stage by “translating” legislative requirements into IT specifications and checking whether the proposed solution truly meets the requirements of Czech legislation and the methodological guidelines of the Ministry of Labour and Social Affairs (MPSV) and the ČSSZ.

The third area is adjusting internal HR and payroll processes. Introducing mandatory registration of employees before they start work, especially foreign nationals, fundamentally changes the timing of recruitment and the handover of documents to payroll. The recruitment process must now include verification that all data necessary to register the employee are available in time, and the internal deadline for entering these data into the system must be set with a buffer before the actual start date. The same applies to termination of employment – HR must provide payroll with information on the end of an employment relationship or agreement so that deregistration from the employee register can be carried out within 8 days and the change reflected in the JMH.

The training element is also significant. The JMHZ introduces new technical terms (e.g., personal identification number OIČ, employment identifier ID PPV, data message, technical and formal defect) and new obligations for persons who have not previously communicated with the ČSSZ in practice. Attorneys from ARROWS, a Prague-based law firm, therefore often prepare targeted training sessions for clients’ management, HR and payroll teams, explaining not only the legal framework but, in particular, practical scenarios, typical errors and their impacts. Training focused, for example, on HR may address how to properly set up communication with candidates so that all data required for REGZEC can be obtained in time without breaching GDPR or anti-discrimination rules.

Last but not least, it is advisable to set up internal control mechanisms and “fallback” scenarios. This includes, for example, an internal checklist for payroll closing and JMH preparation, regular checks of the employee register extract on the ČSSZ ePortal, internal review of the first JMH filings, and a scenario for handling situations where the JMH is returned with an error or a request for correction. As part of long-term cooperation, attorneys from ARROWS, a Prague-based law firm, can act as an external “controller of last resort”, continuously evaluating legislative changes and updates to methodological guidance from the MPSV and the ČSSZ and recommending adjustments to processes or software.

Specifics for foreign employees and cross-border structures

JMHZ has a significant impact on employers using foreign workers. The Act introduces a stricter regime for registering foreign nationals, under which an employee who is not a Czech national must be reported in full to the employee register no later than before commencing work, while registration may be submitted at the earliest 8 days before the expected start date.

The REGZEC filing must include all data required by law, including details of the type of residence permit, passport/travel document number, the type of work authorisation (e.g., employee card, Blue Card, intra-company transferee card) and other parameters.

At the same time, the process of registering employees – foreign nationals in the JMHZ system replaces the existing information cards and notifications under Section 87 of the Employment Act, to the extent relating to the commencement of employment and the performance of work by a foreign national. In some cases, however, the information obligation is still fulfilled via the portal of the State Labour Inspection Office (Státní úřad inspekce práce, “SÚIP”), for example for workers posted in the course of providing services on the EU internal market. Employers therefore must distinguish which situations fall exclusively under JMHZ, which under SÚIP, and which under both systems simultaneously, which is difficult without expert knowledge of Czech employment law and employment regulations.

Cross-border scenarios under EU law deserve special attention. Under EU law, an employee is generally insured in the social security system of only one Member State; in the case of posted workers, they generally remain insured in the employer’s home country provided the posting does not exceed 24 months and the relevant conditions are met. For these purposes, the A1 form is used, confirming affiliation to the social security system of a particular country. 

However, JMHZ addresses the registration of employees and employment in the Czech social security system; for cross-border structures it is therefore necessary to clearly determine whether a particular worker falls under the Czech system (and must be recorded in the JMHZ register) or remains insured in another state.

In practice, for larger groups we encounter, for example, a situation where a parent company in another EU country posts its employees to a Czech subsidiary. If the workers are genuinely posted within the meaning of the European rules and have an A1 form, social security contributions are paid by the employer in the home state and the Czech subsidiary usually does not become the employer for JMHZ purposes. 

However, if the worker is in the Czech Republic in fact integrated into the structure of the Czech entity, or if it is a long-term or repeated posting, the situation may be assessed differently and JMHZ will be relevant. In these complex scenarios, close cooperation with tax and immigration specialists is essential, which is a typical agenda handled by the attorneys of ARROWS advokátní kancelář in cooperation with partners within the ARROWS International network.

Another sensitive topic is combinations of different roles of one person within a group of companies, for example a member of a statutory body in one company and an employee in another, with both roles linked to the Czech Republic. In the context of JMHZ, it is necessary to assess whether the individual roles give rise to employment income with a specific Czech entity and thus a registration and reporting obligation, or whether these are purely foreign or business relationships.

 An incorrect assessment may lead both to an additional assessment of social security contributions and to fines for missing JMH. Here, the role of the lawyers from ARROWS advokátní kancelář is key – it involves a combination of corporate, tax, employment and international law.

ČSSZ inspections and defence against sanctions

JMHZ also changes the way ČSSZ works with employers’ data and how it identifies risk situations. Thanks to centralised and detailed data at the level of individual employments, ČSSZ can largely automate inspections – for example, comparing contribution data with wage data and hours worked, monitoring inconsistencies between the recorded duration of employment and registrations/deregistrations, or identifying missing JMH for a specific period. 

This increases the likelihood that errors that remained hidden in the past will now be detected relatively quickly. The inspection process usually begins with a notice from ČSSZ – either to submit JMH (if it was not submitted or is ineffective as a whole) or to correct it (if the submission was partially accepted). 

The time limit to respond is 8 days from delivery of the notice in both cases, which in practice means a very short timeframe to trace and correct errors, especially for a larger employer with a complex payroll agenda. If the employer does not respond to the notice or fails to remedy the issue in time, ČSSZ may initiate misdemeanour proceedings and impose a fine under the JMHZ Act.

In misdemeanour proceedings, it is advisable to raise all relevant arguments that may lead to a reduction or waiver of the fine – for example, proving that the employer remedied the error without delay after discovering it, that it is a first-time breach, that no harm occurred to employees’ entitlements, or that the error was contributed to by an unclear methodological interpretation or a technical problem on the part of a third party (e.g., payroll software). 

In these situations, it is common for businesses to use the services of lawyers from ARROWS advokátní kancelář, who can communicate with ČSSZ in terms the authority understands, while also ensuring that the arguments are consistent with current case law and methodology.

If the employer disagrees with the imposed fine, it may defend itself using the standard remedies under the Administrative Procedure Code, which include an appeal and, in the last resort, an administrative action. The usefulness of subsequent steps always depends on the amount of the fine, the circumstances of the case and the evidentiary situation – sometimes it is more rational to accept a lower sanction and focus on preventive measures; other times it makes sense to defend the matter in court as well, for example if the sanction would create a dangerous precedent for the company.

In addition to the classic ČSSZ inspections, it should be expected that JMHZ will also be used by other authorities – the Financial Administration, the Labour Office, or the Czech Statistical Office. Incomplete or inconsistent data in JMH may lead to notices or inspections from their side as well, for example if inconsistencies are identified in the area of withholding tax, the employment of jobseekers, or statistical reporting. This reinforces the importance of an integrated legal, tax and HR approach, which is typical of the services of ARROWS advokátní kancelář.

Final summary

The Unified Monthly Employer Report represents the biggest change in payroll and HR administration in the Czech Republic in recent years. It is a complex digitalisation project that gradually replaces up to several dozen existing reports with a single monthly electronic submission and introduces a centralised register of employers, employees and individual employments.

From the perspective of a business owner, investor or senior executive, however, this is not merely a technical innovation – the new system significantly increases the demands on data and process quality while also creating room for more frequent and more detailed inspections by ČSSZ and other authorities.

Key practical risks primarily include failing to register the employer or employees, filing the JMH after the deadline, technical or formal defects in the data message, inconsistencies between the OIČ and employment ID identifiers, and an incorrect assessment of who qualifies as an “employee” for JMHZ purposes. Failure to file or correct the JMH may result in fines of up to CZK 5,000 per employee; breaches of registration obligations may be fined up to CZK 100,000; and there may also be indirect losses in the form of delays or refusals of employee benefits, reputational impacts, and disputes over compensation for damage.

For companies, it is therefore sensible to treat JMHZ as a project that requires coordination across HR, payroll, IT, finance, and legal. An appropriate approach is to carry out an audit of data and processes, align payroll software with Czech legislative requirements, set up new HR and recruitment processes (especially for foreign nationals), train responsible persons, and implement internal control mechanisms and “fallback” scenarios in case of requests from the Czech Social Security Administration (ČSSZ). 

Attorneys from ARROWS, a Prague-based law firm, can act as a partner in this process—one that not only ensures compliance with the applicable legal framework and methodological guidance, but also understands the impact JMHZ has on cash-flow management, benefit structures, recruitment strategy, or intra-group transactions.

If you do not want to risk unnecessary errors, losses, delays, or fines in connection with JMHZ, it is safer to entrust the setup of the entire system to professionals. ARROWS, a Prague-based law firm, can assist you with the legal and tax assessment of JMHZ impacts on your company, the preparation and review of internal policies, setting up registration and JMH filing processes, representation during inspections, and defence against any sanctions. For an individual consultation and a proposed course of action, you can contact the attorneys at ARROWS, a Prague-based law firm, at any time by e‑mail at office@arws.cz.

FAQ: Most frequently asked questions

1. How can I tell whether our company falls under the JMHZ regime if we only have a few external contractors and members of corporate bodies?
The decisive factor is whether your company pays income from dependent activity under Section 6 of the Czech Income Taxes Act—typically wages, remuneration of members of corporate bodies, remuneration under work agreements, etc. If so, you are a payer of tax on income from dependent activity and, for JMHZ purposes, you are considered an employer—even if in practice you employ only one person and only for a few months a year. If you are unsure, it is advisable to have the specific situation assessed by the attorneys at ARROWS, a Prague-based law firm—you can contact them at office@arws.cz.

2. What happens if we fail to submit the JMH for a given month by the 20th day of the following month?
In that case, you will be in default with the JMH filing, and after the deadline expires, the Czech Social Security Administration (ČSSZ) will invite you to submit the report within an additional eight-day period; if you still do not submit the JMH, you may face a fine of up to CZK 5,000 for each employee for whom the report should have been filed. At the same time, there may be delays in processing benefits and other agendas, which can create pressure from employees. In such a situation, it is advisable to act quickly and address any sanctions with the support of the attorneys at ARROWS, a Prague-based law firm, whom you can reach at office@arws.cz.

3. What are the most common technical errors in the JMH and how can we prevent them?
According to the Czech Social Security Administration (ČSSZ), the most common errors include failure to complete mandatory fields, use of incorrect code-list values, inconsistencies between the OIČ and employment ID identifiers, and attempts to upload XML via the wrong ePortal service. Prevention lies in high-quality data preparation in the payroll system, testing exports, and setting up an internal process to review the JMH before submission. Attorneys from ARROWS, a Prague-based law firm, can help you design these processes and communicate with your software provider—just write to office@arws.cz.

4. What is the correct procedure if we discover an error in a JMH already submitted, for example an incorrectly reported assessment base?
In that case, it is necessary to submit a corrective report for the month concerned, replacing the incorrect data with the correct data; the JMH can be corrected both on the basis of a request from the Czech Social Security Administration (ČSSZ) and on your own initiative, even after the original filing deadline has passed. As a general rule, the sooner you remedy the error, the lower the risk of sanctions and impacts on employees’ entitlements. For the correct setup of corrections and communication with ČSSZ, it is advisable to use the support of the attorneys at ARROWS, a Prague-based law firm—contact them at office@arws.cz.

5. What specific steps should we take as part of preparing for JMHZ already this year?
Typically, these are three parallel steps: an audit of employee and employment-relationship data (including completing missing information), coordination with the payroll software provider regarding JMHZ support, and adjusting internal HR and payroll processes so that registrations can be made and JMH filings submitted on time. For larger and mid-sized companies, it makes sense to approach JMHZ as a project with a clear plan, deadlines, and responsibilities—attorneys from ARROWS, a Prague-based law firm, can help you design and manage it, and you can contact them at office@arws.cz.

6. Does it make sense to address JMHZ with a law firm if we have an experienced payroll accountant and good software?
An experienced payroll accountant and quality software are a strong foundation, but JMHZ also affects areas that go beyond purely payroll agendas—for example, the definition of an employee, benefit structures, cross-border situations, management liability for administrative offences, or links to tax and immigration regulations. Attorneys from ARROWS, a Prague-based law firm, bring a perspective on these legal and business implications, help you set up processes that will stand up to an inspection, and, in the event of a dispute or fine, provide qualified defence. If you want to be sure that the JMHZ system in your company is truly robust, write to office@arws.cz.

Disclaimer: The information contained in this article is for general informational purposes only and serves as a basic guide to the issue as of 2026. Although we strive for maximum accuracy, laws and their interpretation evolve over time. We are ARROWS Law Firm, a member of the Czech Bar Association (our supervisory authority), and for the maximum security of our clients, we are insured for professional liability with a limit of CZK 400,000,000. To verify the current wording of the regulations and their application to your specific situation, it is necessary to contact ARROWS Law Firm directly (office@arws.cz). We are not liable for any damages arising from the independent use of the information in this article without prior individual legal consultation.

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