Statute of Limitations for Taxes 2026

The Basic Principle: The Preclusive Period for Tax Assessment as a Protection for the Taxable Person

A preclusive period means that after it expires, the tax administrator's right to assess or additionally assess a tax is extinguished. In short: after this period expires, the tax office cannot assess additional taxes without any limitation, and it must take the extinguishment of the right into account ex officio under Section 148(1) of the Tax Code.

The basic length of the preclusive period for tax assessment is three years and begins on the day on which the deadline for filing the regular tax return expired. However, this three-year period is a general rule, and in practice, there are many situations that can significantly extend it. For taxpayers who are not familiar with the details of tax law, this often means the surprising appearance of the tax office with an additional assessment several years after they thought they were safe.

The lawyers at ARROWS law firm deal with these limitation periods daily as part of our Tax Law and Disputes service and know exactly which situations can lead to the halting of the running of these periods. Understanding these mechanisms is crucial not only for defending against an already initiated audit but also for preventive planning and documentation.

The Difference Between Preclusion and Limitation – and Why It Matters

Before we delve into the details of limitation periods, it is important to understand a fundamental legal distinction under Czech legislation. While a preclusive period means the extinguishment of the right itself, so the subjective right ceases to exist and the authority must take this into account on its own initiative under Section 148 of the Tax Code, a limitation period means that the right does not cease to exist but becomes unenforceable if the debtor invokes the statute of limitations.

In tax law, it is necessary to distinguish between two basic phases:

• Period for tax assessment (additional assessment) – this is a preclusive period. If it expires, the tax office cannot make an additional assessment, and you do not have to object; the state's right has been extinguished.

• Period for tax payment (collection of arrears) – here we speak of the limitation of the right to collect and enforce the tax. Here, it is necessary for the taxpayer to raise an objection of limitation if the authority wants to collect an old debt after the period has expired.

Both types of periods have fundamental consequences for taxpayers, and in 2026, it is advisable to systematically review all these periods.

The Three-Year Period – When Does It Actually Start and in What Situations Does It Apply?

The preclusive period for tax assessment begins on the day on which the deadline for filing the regular tax return expired, as stipulated in Section 148(1) of the Tax Code. For taxpayers who are required to file a return, this is the exact day of the statutory filing deadline. For example, for individuals filing electronically, the deadline is usually 2 May, while for entities with a tax advisor, it is 1 July.

If the taxpayer was not required to file a tax return, the period for tax assessment begins on the day the tax became due. This is particularly important for specific taxes or situations where there is no obligation to file a return.

In practical terms, this means that if you are a legal entity and the deadline for filing your 2023 tax return was 1 July 2024 (with a tax advisor), the three-year period runs from that day and will end on 1 July 2027. If the tax office delivers an additional tax assessment notice to you on 2 July 2027, its decision will be unlawful (unless another event extending the period has occurred).

It is important that both the tax administrator and the court must take the expiration of this preclusive period into account ex officio. This means that even if you do not invoke the limitation yourself, the authority is not allowed to assess the tax after this date.

Special Calculation of the Period and the Influence of the Calendar Year

Unlike procedural deadlines for filing returns, where the deadline is moved to the next working day if it falls on a weekend or holiday, the end of the preclusive period is a matter of substantive law. According to the case law of the Supreme Administrative Court, the preclusive period ends on the given day, regardless of whether it is a weekend or a holiday. The tax office must therefore manage to issue and notify the decision (or perform the act) on this day at the latest.

Another important specific is that the running of the period does not respect the transition between calendar years. This means, for example, that a three-year period that began on 1 April 2024 will end on 1 April 2027.

Extension of the Basic Three-Year Period – When Three Years Become Four or More

The Tax Code explicitly specifies situations in which the preclusive period for tax assessment is extended by one year. These extensions are not arbitrary – if any of the situations defined by law occur in the last twelve months before the expiration of the current period, the extension occurs by law under Section 148(2) of the Tax Code.

Note: it is not enough for the taxpayer to file an amended return at any time – it must be done in the last twelve months before the expiration of the current period. So, if the standard three-year period ends on 1 April 2027, and you file an amended return on 30 March 2027, the period will be extended by another year, i.e., until 1 April 2028.

The second situation is the notification of a decision on tax assessment (e.g., an additional tax assessment notice) in the last twelve months before the period expires. The third situation is the initiation of proceedings on an extraordinary remedy, a supervisory remedy, or proceedings to declare a decision null and void during this critical period.

The lawyers at ARROWS law firm will help you with a thorough analysis of whether filing an amended return now is strategically advantageous for you, or whether it is better to choose a different course of action. 

Practical Example of Period Extension – Chain Extensions

Imagine this situation: you have an income tax with an assessment period ending on 1 April 2026. On 1 March 2026 (i.e., in the last twelve months), the tax office notifies you of a call to file an amended tax return (and you make an additional assessment based on it). At this moment, your period is extended by one year, i.e., until 1 April 2027.

However, this chain has a limit. The ultimate deadline for assessing tax is always the expiration of ten years from the beginning of the basic period for tax assessment under Section 148(5) of the Tax Code. However, there are exceptions: the period can also be extended in the case of a final court decision on the commission of a tax crime – in such a case, the tax can be assessed until the end of the second year following the year in which the court's decision became final.

Interruption of the Period – How It Starts Anew

While an extension means that the period is prolonged by one year, an interruption of the period means something significantly more unfavorable: the period is nullified and begins to run again in its full three-year length.

As soon as the tax office delivers a notice of the initiation of a tax audit (or draws up a protocol), the period for tax assessment is interrupted and a new three-year period begins to run from the day this act was performed. In practice, this means that if you thought you would be safe in two months, and you receive a notice of the initiation of a tax audit, the "countdown" starts again from three years.

Other situations leading to an interruption are the filing of a regular tax return (e.g., if you did not originally file it and are filing it late) or the notification of a call to file a regular tax return. In these cases, a new three-year period is calculated from the date of the act without exception.

This rule has major implications for taxpayers. A "wait-and-see" strategy can backfire if the tax office initiates an audit just before the end of the period.

Tolling of the Period – When the Clock Stops

In addition to extension and interruption, the Tax Code also recognizes the concept of tolling the period. If the period is tolled, it does not run at all. After the obstacle is removed, the period continues from where it left off and will not end earlier than a certain period, as regulated by Section 148(4) of the Tax Code.

Therefore, if you are in a dispute with the tax office before an administrative court, the period for tax assessment does not run in the interim. The period primarily does not run during proceedings before a court in administrative justice concerning this tax, pursuant to Section 148(4)(a) of the Tax Code.

The second common situation where the period is tolled is an international request for assistance (see below). Furthermore, the period is tolled for the duration of criminal prosecution for a tax crime related to this tax.

Corporate Debt and Limitation – When the State's Time to Collect Runs Out

It is also necessary to mention the difference between the period for tax enforcement (the period for tax payment) and the period for its assessment. While the period for tax assessment protects you from the tax office assessing additional tax, the period for tax payment determines how long the tax office has the right to collect a tax arrear. This period is six years from the tax due date under Section 160(1) of the Tax Code.

The court and the tax administrator will only take the statute of limitations into account if it is raised as an objection by the debtor. Therefore, if you were to voluntarily pay a time-barred tax, the tax office would not refund it. However, if you object on the grounds of limitation, the right to collect is extinguished.

The period for tax payment can be extended by actions aimed at collecting the tax (e.g., enforcement), with the absolute upper limit being twenty years from the tax due date (with the exception of secured arrears) under Section 160(5) of the Tax Code. If the tax claim is secured by a lien that is registered in a public register, the right to collect the tax is not subject to a statute of limitations for thirty years from the registration.

International Cooperation and Local Investigations – Hidden Risks of Tolling the Period

In recent years, it has become common for the period for tax assessment to be suspended (tolled) in connection with international cooperation. Specifically, these are situations where the tax office sends a request for assistance abroad to obtain information. In these cases, the period does not run from the day the request is sent until the day the tax office receives a response or a notification that the request has been closed.

However, according to the case law of the Supreme Administrative Court, an international request for assistance must be assessed on its merits. In practice, this means that if you think you will be safe in a few months, and the tax office sends a request for assistance abroad in the meantime, the clock stops. If the request was completely unnecessary, served a different purpose, or clearly could not yield relevant information, the courts may rule that the period was not tolled.

The lawyers at ARROWS law firm deal daily with cases where clients are waiting for a response to an international request for assistance. In these situations, it is important to be able to defend yourself and support your defence with evidence as to whether the request was justified.

Tax Crime and Effective Repentance

If the tax office discovers a large-scale intentional tax evasion, the matter can move to the level of criminal law. Here, it is necessary to distinguish between two concepts: the extinguishment of criminal liability for the act due to effective repentance (under the Criminal Code) and the reduction of the penalty (under the Tax Code).

According to the Criminal Code, criminal liability for the crime of tax evasion is extinguished if the perpetrator voluntarily rectifies the harmful consequence and notifies the authority before the court of first instance begins to pronounce the judgment. This is a rather generous deadline that provides an opportunity to "buy one's way out" even during the investigation.

However, from the perspective of the Tax Code and financial sanctions, if you file an amended return only after a tax audit has been initiated, you will not avoid the standard penalty of 20% of the additionally assessed tax under Section 251(1)(a) of the Tax Code. However, if you correct the mistake yourself before an audit is initiated, no penalty is incurred (you "only" pay late payment interest under Section 252 of the Tax Code).

The lawyers at ARROWS law firm regularly assist clients with preparing amended tax returns in a way that minimizes risks on both levels. The strategy therefore differs depending on whether you are facing "only" an additional tax assessment with a penalty, or criminal prosecution.

When the Period Is Extended Anyway – Defence Strategies and Verifying Legality

If the tax office notifies you of a tax audit or issues a decision on an additional tax assessment, you should first verify whether all legal conditions have been met and whether the period has not already expired.

In such a case, it is necessary to thoroughly verify the start of the period, all acts that interrupt or extend the period, and their validity. If it turns out that the decision on the additional tax assessment was issued or notified after the preclusive period had expired, such a decision is unlawful and must be annulled. The lawyers at ARROWS law firm focus on detailed chronology (period audits).

How to Defend Procedurally – Appeal and Lawsuit

If the tax office issues a decision on an additional tax assessment and you believe that the period has already expired, the basic means of defence is an appeal under Section 109 of the Tax Code. The appeal is filed with the tax administrator who issued the decision, within 30 days of the decision's delivery. In the appeal, it is necessary to object that the preclusive period has expired – even though the authority is supposed to take it into account ex officio, an active defence is key.

Administrative courts assess whether the tax administrator acted in accordance with the law and whether a decision allegedly issued out of time can stand. If your appeal to the Appellate Financial Directorate is unsuccessful, the next step is an administrative action before the regional court under Section 65 et seq. of the Code of Administrative Justice.

The lawyers at ARROWS law firm have many years of experience in handling these cases and help clients with argumentation and evidence strategy. In practice, these disputes are legally demanding.

Archiving Tax Documents – How Long You Must Keep Evidence

In order to defend effectively, a taxpayer must have documents available. However, the archiving periods differ depending on the type of document and the taxpayer's status.

If you are a VAT payer, you must, according to the Value Added Tax Act, keep tax documents for 10 years from the end of the tax period in which the transaction took place. This ten-year period is key in practice, and it is safer to follow it for other taxes as well if you keep accounts.

For entities that are not VAT payers and do not keep accounts (e.g., using lump-sum expenses), the minimum archiving period is tied to the period for tax assessment (i.e., the basic 3 years + any extensions). However, given the possibility of extending the periods up to 10 years, we strongly recommend keeping records for a longer period.

The lawyers at ARROWS law firm repeatedly see cases where taxpayers do not have documents during an audit because they shredded them after three years. This leads to a failure to meet the burden of proof and an additional tax assessment.

Electronic vs. Physical Archiving

In modern practice, it is important to adhere to the rules of electronic archiving. A document in electronic form must have its authenticity of origin, integrity of content, and legibility guaranteed for the entire retention period.

This can be achieved, for example, with qualified electronic signatures and time stamps, or by using a trusted repository. Simply saving a scanned invoice to a disk without security may not stand up in court as credible proof of origin after several years.

Specific Situations – Tax Losses and Their Impact on the Running of the Period

A tax loss has a fundamental impact on the running of the period for tax assessment. According to the Income Tax Act, the period for assessing tax for the tax period in which the tax loss arose ends at the same time as the period for assessing tax for the last tax period for which this tax loss can be utilized, as stated in Section 38r(2) of the Income Tax Act.

Moreover, due to the possibility of carrying back the loss, the periods for previous periods may also be opened. Since a tax loss can be utilized in the 5 subsequent tax periods, the period for the year the loss arose is "chained" and remains open for much longer (realistically about 8 or more years).

Practical consequences: if you report a tax loss in 2024, the tax office can audit that year until the period for 2029 expires. The taxpayer can get rid of this extension if they waive the right to utilize the loss, within the deadline for filing the return for the period in which the loss arose.

The lawyers at ARROWS law firm recommend conducting an analysis before utilizing a loss to determine whether the tax savings outweigh the risk of keeping the accounts open for audit for a long time.

Practical Recommendation – How to Verify Your Tax Security in 2026

The year 2026 is a good time to systematically review your tax history. We recommend the following procedure:

• List the dates: When were returns filed for recent years (2020–2025), when were the due dates, were amended returns filed, or were audits initiated.

• Calculate the periods: For each year, determine the end of the basic three-year period. Add extensions for amended returns (+1 year) or restart the period where an audit took place.

• Audit your documents: Verify that you have available (and legible) documents for all "open" periods.

• Consider your strategy: If you are aware of risks in open periods, consult with experts about options for correction (amended return) before an audit comes.

The lawyers at ARROWS law firm deal with such situations daily and can identify which tax risks remain current and which have already been extinguished.

Executive Summary for Management

Basic periods: The tax office typically has 3 years to make an additional tax assessment. This period is calculated from the deadline for filing the return. The maximum period is 10 years (with the exception of criminal offences).

Extension risks: Filing an amended return in the last year of the period extends it by 1 year. The initiation of a tax audit interrupts the period, and it starts to run again in its entirety (3 years).

Loss as a risk: Reporting a tax loss keeps the year in which the loss arose "open" for the period during which it can be utilized (approx. an additional 5-6 years).

Defence: A decision issued after the period has expired is unlawful. However, it is necessary to actively defend yourself (appeal). Archive documents for at least 10 years (VAT payers) to meet the burden of proof.

Prevention: A proactive audit of periods and archiving is cheaper than resolving disputes. If you are unsure, have a legal analysis of the periods performed.

Conclusion of the Article

Tax periods and preclusion are one of the most complex topics in tax administration. Although it may seem that a taxpayer is safe after three years, the reality is more complicated. There are a number of situations where periods are extended, interrupted, or tolled.

The year 2026 is an ideal time to review your tax history. This is not just about administration – it is about protecting against financial risks that could threaten your business.

The lawyers at ARROWS law firm have many years of experience in dealing with tax periods. Our portfolio includes over 150 joint-stock companies and 250 limited liability companies that we have helped with tax problems. ARROWS law firm is insured for damages up to CZK 350 million, which allows us to provide you with comprehensive legal services with a strong background.

If you are not sure where you stand in your tax history and what risks you still face, contact us at consultation@arws.cz. Our lawyers will help you with a detailed analysis of your situation and develop a strategy on how best to proceed.