Red flags from the Czech Tax Administration in your datová schránka

If you run a business in the Czech Republic, you regularly receive letters from the tax administration (Finanční správa) via your datovou schránku. Most of the time these are simple notifications — deadline reminders, acknowledgments of receipt, or other automated messages. But sometimes something more serious arrives.

In this article, we explain which letters should be treated as a red flag, how they differ from routine notifications, what actions you need to take, and by when, so you can avoid fines or other problems.

What letters does the tax office send via datová schránka?

There can be a lot of messages from the Czech Tax Administration (Finanční správa ČR), but in essence they fall into two broad groups — notifications that do not require any action and letters that you must respond to.

Which letters from the Czech Tax Administration do not require a response?

These are technical or informational messages. Their purpose is to inform you, not to make you act. Examples include:

• Reminders — filing deadlines, control statements (kontrolní hlášení), tax payment dates, etc.
• Acknowledgments — confirming that a return was received, the system registered your document, everything is in order.
• General notices — for example, about legislative changes or scheduled maintenance on the portal.
• Replies to your inquiries — if you requested something, the tax office may simply confirm receipt or provide an official answer with no further requirements.

If you open such a letter, just save it — no action is needed.

Which letters and notices from the Czech Tax Administration require a response?

These are no longer routine notifications. In these letters, the tax office requires something from you: to provide clarification, submit documents, pay, or carry out an action within a set deadline. Examples include:

• Requests for clarification or documents
• Notices of the start of an audit
• Decisions on additional tax assessment or penalties
• Notices of arrears and the initiation of collection proceedings

These letters must not be ignored. They almost always come with specific deadlines; missing them can trigger sanctions — from fines to bank account freezes.

H2 Main types of letters from the Czech Tax Administration that require a response — and what to do if you receive them

Below is a list of the most common red-flag letters from the tax administration (Finanční správa ČR). For each type, you’ll see what the letter is, who typically sends it, how serious it is, and what the potential consequences are. Each block ends with guidance on what to do if you receive such a letter.

Request for explanation or documents (Výzva k podání vysvětlení / Výzva k doplnění údajů)

• Sender: a tax inspector (Finanční úřad) or the registration department (oddělení registrace)
• Level of concern: medium
• Consequences if ignored: a fine for non-compliance, potential initiation of a tax audit (daňová kontrola)
• Response deadline: most often 8 or 15 days from delivery to your datovou schránku

This type of letter often arrives unexpectedly. The tax administration (Finanční správa) may ask you to explain a specific transaction, attach supporting documents, or confirm data from a return. Sometimes it’s not about your filing at all but about an audit of your counterparty — yet they will still request information from you. The wording is typically dry and formal, but the signal is clear: the tax office wants to verify that your data is in order.

This is not yet a tax audit, but if you ignore the letter or respond vaguely, there is a high chance you will soon receive a formal notice of the start of an audit. Silence is treated as a breach and almost always works against the entrepreneur.

What to do if you receive a request for explanation or documents (Výzva k podání vysvětlení / Výzva k doplnění údajů)

Start by carefully reading exactly what the tax office is requesting. Do not send unnecessary documents — provide precisely what is asked for. If the request concerns a single transaction, limit your response to the relevant contracts and account statements for that transaction. It is best to prepare the response with your accountant so it is accurate and measured in tone. Stick to facts only — no emotions or speculation.

You can submit your response via the datovou schránku, and it will be deemed official. After sending, make sure to save the delivery confirmation (potvrzení o doručení); this is your protection in case of a dispute.

Notice of commencement of a tax audit (Oznámení o zahájení daňové kontroly)

• Sender: a tax inspector (Finanční úřad)
• Level of concern: high
• Consequences if ignored: fines, limitation of deductions, additional assessments, accrual of interest
• Response deadline: set individually and stated in the letter; the clock starts on the date of delivery to your datovou schránku

This letter always signals the official start of a tax audit. It rarely arrives “out of the blue.” It is usually preceded by the authority’s doubts and prior requests for clarification or supporting documents. If the responses seemed incomplete, contradictory, or were not provided at all, the inspector decides to commence a formal audit.

The document specifies which tax and which period will be examined. Most often it concerns VAT or income tax, but other obligations may be covered as well. The audit can target a single transaction or span the entire reporting period. From this point on, every action you take is recorded and has legal significance.

The inspector is entitled to request primary documents, contracts, accounting statements, and other records. All your replies and explanations become part of the official proceedings. If you ignore such requests or respond perfunctorily, this leads to fines and additional assessments. An audit does not end in a day — it can last for weeks or even years.

What to do if you receive a notice of the start of a tax audit (Oznámení o zahájení daňové kontroly)

First of all, do not panic. Contact your accountant or a tax advisor and show them the letter. Prepare the documents for the specified period and make sure they are organized and readily accessible for review. Every letter and document you send to the inspector should be saved together with the delivery confirmation. Respond strictly to the point — excessive information or attempts to “explain informally” can complicate the process. If you feel uncertain, discuss your strategy with an advisor right away rather than trying to handle it alone.

Notice of commencement of administrative proceedings (Oznámení o zahájení řízení)

• Sender: a tax inspector (Finanční úřad) or the registration department (oddělení registrace)
• Level of concern: high
• Consequences if ignored: a decision issued without your participation, refusal of registration, revocation of status, fines
• Response deadline: stated in the letter; the clock starts from the moment of delivery to your datovou schránku

This letter is also typically preceded by requests for clarification or supporting documents. If no answers were provided or the inspector deemed them unsatisfactory, you will receive a notice of the start of administrative proceedings (Oznámení o zahájení řízení). From this point on, you become a party to a formal procedure. Depending on the situation, it may concern refusal to register as a VAT payer, revocation of an existing status, or other sanctions. The wording is brief and dry, but the consequences for your business can be significant. If you ignore the notice, a decision will be issued automatically and will take effect without your participation.

What to do if you receive a notice of commencement of administrative proceedings (Oznámení o zahájení řízení)

First, carefully read the text of the letter and its attachments to understand exactly what the proceedings concern. Then prepare an objection or explanation. It is best to do this with a lawyer or accountant, as every word in your response matters. Above all, meet the deadline stated in the notice. If you remain silent, the tax authority will issue a decision automatically, and challenging it later will be much more difficult.

Decision on additional tax assessment or a fine (Rozhodnutí o doměření daně / Rozhodnutí o pokutě)

• Sender: a tax inspector (Finanční úřad) or an authorized officer of the Finanční správa
• Level of concern: critical
• Consequences if ignored: automatic entry into force of the decision, accrual of interest, enforced collection, bank account freezes
• Response deadline: 30 days from the date of delivery of the decision to your datovou schránku (unless otherwise stated in the poučení rozhodnutí)

This letter never comes first. It is usually preceded by a tax audit (daňová kontrola) or administrative proceedings (řízení). If the inspector believes your filing contains errors or violations, they issue a decision assessing additional tax or imposing a fine. The document always states the amount and the grounds: refusal of a VAT deduction, understated income, fictitious expenses, or failure to meet filing deadlines.

The wording is dry and formal, for example: «Bylo vydáno rozhodnutí o doměření daně…». Behind that phrase is a concrete requirement — either pay the stated amount or appeal the decision. If you do nothing, it takes effect automatically. The process will then move forward without your involvement: interest will accrue, enforced collection (daňová exekuce) may begin, and your accounts can be frozen.

What to do if you receive a decision on an additional assessment or a fine (Rozhodnutí o doměření daně / Rozhodnutí o pokutě)

First, note the date of delivery to your datová schránka. From that moment, the clock starts for payment or appeal. If you agree with the decision, do not delay — pay the tax or fine on time to avoid interest. If you are confident the tax authority is wrong, prepare an appeal (odvolání). It must be submitted in writing and include arguments: legal references, calculations, and supporting documents. Simply stating «I disagree» is not enough.

Even if the decision seems unfair, you must follow the procedure precisely. Miss the deadline and, regardless of the merits, the document will take effect. In such cases, it is wise to engage a tax lawyer or advisor to prepare a correct and timely response.

Notice of arrears (Výzva k úhradě nedoplatku / Upomínka)

• Sender: the enforcement department (exekuční oddělení) or the Finanční správa automated system
• Level of concern: medium
• Consequences if ignored: transition to enforcement proceedings (daňová exekuce), accrual of late-payment interest
• Response deadline: indicated in the letter, usually 15 days from delivery to your datovou schránku

This letter is sent when the system records an outstanding balance. It may be an unpaid tax, an overdue advance payment, or accrued interest. Sometimes a balance arises from a simple technical error: you paid on time, but the payment was not allocated correctly. For the tax administration, however, that does not matter — as long as the system shows a debt, the obligation to pay remains with you.

The level of concern here is medium. This is not a tax audit and not a final decision, but it must not be ignored. If you leave it unanswered, the next step will be enforced collection, which may result in bank account freezes.

What to do if you receive a notice of arrears (Výzva k úhradě nedoplatku / Upomínka)?

You must respond in any case. If the debt is real, pay it within the deadline and be sure to inform the tax office, for example via the datovou schránku, attaching proof of payment. If you are sure there is no arrears, send a response with evidence as well: a bank statement or confirmation of the prior payment. Silence is treated as acceptance of the debt, and the collection procedure will start automatically. The rule is simple — either pay or prove, but always notify officially.

Decision ordering tax enforcement (Usnesení o nařízení daňové exekuce)

• Sender: the enforcement department (exekuční oddělení)
• Level of concern: critical
• Consequences if ignored: bank account freezes, withholdings from incoming payments, third-party levies, growth of the debt due to interest and enforcement costs
• Response deadline: stated in the letter; the clock runs from the moment of delivery to your datovou schránku

This letter means the tax authority is moving from reminders and demands to compulsory enforcement. The reason is almost always the same — the system shows an outstanding debt that was neither paid nor contested in time. Once the decision is issued, your accounts may be restricted, incoming funds levied, and additional expenses added: execution fees, postal and banking charges. Even if you paid recently but the payment has not yet posted, the process can still start — which is why it is crucial not only to pay, but also to notify the authority officially via the datovou schránku.

Sometimes the decision specifies the method of enforcement. This may include debiting an account, withholdings via payment processors, or other measures. If the debt is disputed, there are safeguards: an objection to actions taken within the enforcement, an application to discontinue enforcement (zastavení daňové exekuce) after full repayment, or a request for an instalment plan (splátkový kalendář) or a deferral (posečkání) for good cause. All of these are effective only within the set deadlines and via official correspondence.

What to do if you receive a decision ordering tax enforcement (Usnesení o nařízení daňové exekuce)

First, verify the amount and the period to which the debt relates, and note the delivery date — all deadlines depend on it. If the debt is real and you can clear it, pay without delay and immediately send the tax authority a message with proof of payment via the datovou schránku or another official channel. If you believe there is no debt or it has already been settled, file an objection with evidence: a bank statement, payment details, an explanation. If a lump-sum payment is not possible, submit a formal request for an instalment plan or a deferral with a brief justification and supporting documents. In every case, do not remain silent — failing to respond almost always leads to account freezes and a growing balance due to enforcement costs.

Decision to cancel VAT registration (Rozhodnutí o zrušení registrace k DPH)

• Sender: the tax office (Finanční úřad)
• Level of concern: high
• Consequences if ignored: loss of VAT payer status, prohibition on issuing invoices with VAT (DPH), possible back-assessment of tax
• Response deadline: 30 days from the date of delivery of the decision (unless otherwise stated in the poučení rozhodnutí)

This letter does not appear out of nowhere. It is usually preceded by requests for clarification, demands for documents, or the authority noticing that you are not filing VAT returns. If you have not reported revenue for a long time, are not paying tax, or show no activity at all, the tax office may deem the registration fictitious and remove you from the VAT payer register (registr plátců DPH). This means you are no longer entitled to issue invoices with VAT and to claim input VAT.

The decision is issued as a formal letter that states the grounds — for example, breach of VAT payer obligations, fictitious registration, or systematic non-compliance with deadlines. If you continue to operate as a VAT payer after cancellation, that constitutes a tax violation.

Sometimes the cancellation is indeed a mistake — for example, the tax office did not receive a return you actually filed. But if you do not challenge the decision in time, it will take effect, and the consequences can be unpleasant: additional assessments, fines, and loss of the ability to work with VAT going forward.

What to do if you receive a decision cancelling your VAT registration (Rozhodnutí o zrušení registrace k DPH)?

If you believe the decision is erroneous, file a formal appeal (odvolání) via the same datovou schránku. It is important to substantiate your position: attach proof of return filings, explain the situation, and include statements if you conduct genuine business activity. Be clear and factual — the tax authority responds only to facts and documents.

If there truly was an error, you can persuade the authority to reinstate the registration. If the registration is genuinely no longer needed, make sure your VAT reporting is correct up to the date of deregistration. Otherwise, consequences may still follow.

Warning of breach of obligations (Upozornění na porušení povinností)

• Sender: Finanční úřad, most often the control department (kontrolní oddělení)
• Level of concern: medium
• Consequences if ignored: if repeated — a fine, initiation of an audit or administrative proceedings
• Response deadline: usually stated in the letter; may be 5 to 15 days from delivery to your datovou schránku

This letter may look harmless — like a formal notice. In reality, it formally records a breach: most often a failure to file a return, a delay in a control statement (kontrolní hlášení), an error in a return, or late payment of tax. The letter may contain a phrase such as: „Zjistili jsme, že jste nesplnili povinnost…“, followed by a brief description of the incident.

Usually this is a “yellow card” — a warning without direct sanctions. But it remains in the tax authority’s system, and if the situation repeats, the Finanční správa will not send another reminder — it will move straight to a fine, an audit, or the opening of administrative proceedings.

In some cases the letter includes a request to explain the situation — in that case you must respond. Even if no response is formally required, it is safer to send a brief explanation, especially if the breach has already been remedied. This signals cooperation and can help prevent escalation.

What to do if you receive a warning of a breach (Upozornění na porušení povinností)

Begin by carefully reading exactly what breach has been recorded. Often it’s something simple — a return for a specific month was not filed. If the issue has already been fixed, send a short explanation via the datovou schránku — e.g., “chyba byla opravena” — with proof of the action taken (a copy of the filed return, payment date, etc.).

If you disagree, substantiate your position with dates, documents, and calculations. There is no need for a long letter — the key is to show that you are not ignoring the matter and that you understand what happened. If you do not respond or repeat the breach, a more serious letter will follow.

Decision refusing registration (Rozhodnutí o zamítnutí registrace)

• Sender: Finanční úřad, registration department (registrační oddělení)
• Level of concern: depends on the situation — medium to high
• Consequences if ignored: inability to operate as a VAT payer, difficulties with counterparties, potential suspicions of tax avoidance
• Response deadline: 30 days from the date of delivery of the decision (unless otherwise stated in the poučení rozhodnutí)

This letter is most often received by companies that applied for VAT registration (registrace k DPH) but failed to convince the authority of their business substance. It may concern new companies without turnover, applicants with no track record, or cases where the tax office sees potential risk — for example, sham activity, lack of real operations, or merely formal office and staff.

The decision typically contains wording such as: „Registrace k DPH se zamítá…“, along with the reasons for refusal. It may also list missing documents and the inspector’s doubts about the applicant’s good faith. The letter itself carries no fines, but it can seriously affect further operations — especially if you already conduct business and planned to operate with VAT.

It’s important to understand that the tax office is not simply reluctant to register you — it proceeds from a presumption of risk. You must therefore either eliminate that risk and reapply with a stronger file, or appeal the refusal by providing more persuasive evidence.

What to do if you receive a decision refusing registration (Rozhodnutí o zamítnutí registrace)?

If VAT-paying clients are critical for you, do not delay. First determine the reason for refusal: missing documents, insufficient activity, no real office or turnover? Your tactics will differ accordingly.

Sometimes it is simpler to remedy the deficiencies and submit a new application with an improved package. But if you are convinced the refusal is unlawful, file an appeal (odvolání). It must be precise: legal citations, calculations, copies of contracts, client correspondence, bank statements. Only then can you persuade the authority of your good faith. Above all, do not treat the refusal as a final verdict — it is not a ban, but rather a call to provide better explanations.

Notice of review or correction of data (Oznámení o opravě / Oprava registru)

• Sender: Finanční úřad, registration department (registrační oddělení)
• Level of concern: low to medium, depending on the nature of the changes
• Consequences if ignored: discrepancies in the registry, possible bookkeeping errors, risks that transactions or filings may be deemed invalid
• Response deadline: not always specified, but if you disagree — respond immediately

This letter arrives when the tax authority has changed information about your company in its registers. It may be something minor — for example, updated contact details, a change of the responsible inspector, or a switch in the communication format. It can also be more serious — an adjustment to your registration status, tax identification number (DIČ), changes to territorial competence (místní příslušnost), or your business activity classification.

You may see wording such as: „Došlo k opravě údajů v registru…“ or „Změna registrace byla provedena…“, followed by a list of changes. If you recently submitted a change request, there is nothing to worry about. But if you did not file anything and still received the letter, carefully verify the data.

Keep in mind that any mismatch between your company’s actual details and what the tax authority sees can lead to misunderstandings, blocked correspondence, returned filings, or technical errors in Finanční správa systems. In some cases it may even result in suspended registrations or audits.

What to do if you receive a notice of review or correction of data (Oznámení o opravě)

If you yourself requested the change, simply check that everything has been recorded correctly. In that case, the letter is a formal confirmation.

If you were not expecting any changes, compare the new information with your corporate documents and what appears on the tax portal (for example, in the registru plátců DPH). If you find an error, immediately write to the Finanční úřad via the datovou schránku with an explanation and, if needed, copies of supporting documents. If you remain silent, the system will treat the new data as official — and any errors can later lead to serious consequences.

How the tax authority determines the delivery date in the datová schránka

In the Czech Republic, letters from the tax authority (and other public bodies) sent via the datová schránka are considered delivered even without your confirmation. This rule is set out in § 17 of Act No. 300/2008 Sb.

Legally, delivery is determined as follows.

1. If, after the message is posted, you log in to the datová schránka and open it — delivery occurs at the moment of login, not at the moment of opening.
2. If you log in to the datová schránka but do not open the message — it is still considered delivered as of the moment of login.
3. If you do not log in to the datová schránka at all — the fikce doručení applies, and delivery is deemed to occur on the 10th calendar day after the message was posted.

Why the delivery date of a tax letter in the Czech Republic is very important

Many letters from the tax authority carry strict deadlines for a response, an objection, or an appeal. This deadline runs not from when you read the letter, but from the moment of its legal delivery. And if you never log in to the datová schránka, or you happen to log in and overlook the new message, the clock still starts. Therefore, be sure to enable notifications of new messages and regularly review everything that arrives there so you do not face serious problems.

Conclusion

We have covered only the main types of letters you can receive from the Czech Tax Administration (Finanční správa ČR) via the datová schránka, and the typical actions that may be required of you. In practice, there are many more kinds of notices, and each letter can contain nuances that affect deadlines, consequences, and available remedies.

Tax matters in the Czech Republic are strictly formalistic: even a small delay or an improper response can lead to fines, account freezes, or other serious consequences. This is especially true for entrepreneurs and companies, who are subject to strict rules and timelines.

Therefore, if you are unsure how to respond to a letter from the datová schránka, do not wait — consult a specialist right away.

The DoMyTax team helps entrepreneurs and companies in the Czech Republic manage their relationship with the tax authority: from analysing notices to preparing official responses, filing appeals, and representation in disputes. We know how to speak the Finanční správa’s language — with legal precision and within all deadlines.

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