Unified Monthly Employers' Report (JMHZ 2026)

Official promise versus reality: What is the JMHZ really?

But don't be fooled. In reality, the JMHZ (Unified Monthly Employer Report) is primarily a state tool for creating a massive, real-time database on the labour market and income. Although the submission will be unified, data preparation becomes exponentially more complex, as a single report can contain up to 400 different data items. The state is thus effectively shifting the burden of data collection and verification directly onto you.

How to avoid getting tangled in the schedule and breaking the law?

Misinterpreting the timeline is the fastest way to run into problems. The implementation is not a single step, but three phases with different rules.

• From 1 January 2026: The law is effective, but reports are not yet submitted. However, your key obligation is to start collecting all new, detailed data, even though you will only submit it several months later.

• From 1 April to 30 June 2026: In this hybrid model, you will already be submitting live JMHZ reports for April and subsequent months. At the same time, you will retroactively submit three separate reports for January, February, and March. An important exception: For registering employees (Czech citizens), the current 8-day deadline AFTER starting work still applies.

• 20 May 2026: This is the deadline for submitting the first standard monthly report, for April 2026.

• From 1 July 2026: A new, strict obligation comes into force. You must register every employee BEFORE they actually start performing work.

Correctly setting up processes in line with this complex schedule is key. The lawyers at ARROWS specialise in this issue and will prepare internal guidelines for you to ensure your company meets all legal deadlines. For an immediate solution to your situation, write to us at konzultace@arws.cz.

New obligations in practice: From technical setup to report content

The promise of simplification crumbles when you look at the scope of newly required data. Prepare to report information you have not systematically tracked before:

• Agreements to perform work (DPČ) with remuneration below the threshold for insurance participation.

• Detailed statistical data for the Czech Statistical Office (ČSÚ), such as the highest level of education achieved by each employee.

• A detailed breakdown of all income, including non-taxable income, which will allow the Financial Administration to conduct its own assessment of its taxability.

Furthermore, the implementation of the JMHZ requires thorough technical and data preparation. Paper submissions are definitively ending, and all communication will take place exclusively electronically, in one of the following ways:

• Data message in XML format (via data box).

• Direct connection via API interface (VREP/APEP).

• Manual completion on the ČSSZ ePortal (suitable only for companies with a minimum number of employees).

A fundamental innovation is the introduction of two unique identifiers that your systems must be able to process and assign correctly:

• Personal Identification Number (OIČ): A unique code for each employee that will accompany them across all state institutions.

• Employment Relationship Identifier: A unique code for each individual employment relationship (including agreements to complete a job (DPP) and agreements to perform work (DPČ)) that will allow for precise recording of concurrent employment.

Warning, health insurance companies remain outside the system!

One of the biggest pitfalls is the fact that obligations towards health insurance companies remain unchanged. Even after the launch of the JMHZ, you will still have to send separate reports and statements to each health insurance company individually. You will thus be operating a dual system, which increases the administrative burden and the risk of errors.

Employee registration: The biggest change and the highest risk

The most fundamental and riskiest change brought by the JMHZ is the abolition of the current eight-day deadline for employee registration and the introduction of mandatory registration before they start work. This change will require a complete overhaul of your onboarding processes. The existing "Notice of Commencement of Employment" (ONZ) form is being abolished and replaced by a new, much stricter process.

This obligation applies to all employees without exception, including those working on agreements to complete a job (DPP) and agreements to perform work (DPČ), regardless of their income level or participation in sickness insurance.

Rules for foreigners (effective from 1 April 2026)

The strictest regime applies to employees without Czech citizenship. You must complete their full registration with all data no later than before they start performing work. It is not possible to use the simplified, partial pre-registration for foreigners. This regulation is a direct follow-up to the tightening of the Employment Act from October 2025, which introduced the concept of undeclared work with a penalty of up to CZK 3,000,000.

Rules for Czech citizens (effective from 1 July 2026)

For Czech citizens, the obligation to register also applies before starting work. However, the law allows for a two-phase procedure here: perform a partial registration before commencement and report the remaining data within 8 days after starting. If an employee you have already registered does not end up starting, you are obliged to cancel this registration within 8 days.

How can you avoid crippling fines?

The JMHZ penalty model is uncompromising. A fine of up to CZK 5,000 is threatened for late or incorrect reporting for each individual employee affected by the error.

A simple error in a batch file for a company with 500 employees can thus lead to a fine of CZK 2.5 million. Moreover, the submission deadline is fixed, with no possibility of individual extension or waiver. If you do not register yourself as an employer or your employee on time, you face a fine of up to CZK 100,000. If a foreigner starts working before being properly registered, the State Labour Inspection Office can impose a fine of up to CZK 3,000,000.

If the ČSSZ finds an error in your report, it will ask you to correct it. You have 8 days from the delivery of the notice to do so. Fortunately, the system allows for the submission of a corrective report up to 10 years retroactively.

The best defence against penalties is prevention. ARROWS lawyers specialise in preparing documentation that will protect you from fines and inspections. We provide comprehensive legal services from contract review to representation before administrative authorities. Contact us at konzultace@arws.cz and get a tailor-made legal solution.

How to prepare for the JMHZ and what you can do right now?

Underestimating preparation does not pay off. We recommend starting immediately and focusing on four key areas:

1. Conduct a data audit: Check whether you have all the newly required data in your systems, such as the highest level of education of your employees.

2. Communicate with your software supplier: Verify that your payroll system will be ready for the JMHZ in time and will support submission via API interface.

3. Redesign HR processes: Adjust the recruitment process to comply with the obligation to register an employee before they start work (effective from 1 July 2026).

4. Train your people: Familiarise payroll accountants and HR specialists with the new rules and risks.

We provide comprehensive preparation for the JMHZ for our clients, including those with an international scope. Thanks to our ARROWS International network, we handle labour law issues with an international element on a daily basis and are able to set up processes even in multinational corporations. We will arrange expert training for you, prepare the necessary internal guidelines, and review existing documentation. Contact us at konzultace@arws.cz and get a tailor-made legal solution.