Deadlines and obligations for the self-employed (OSVČ) 2026: tax and insurance calendar
Find all the OSVČ deadlines for 2026: due date of the flat-rate tax, tax return and DPH (VAT) deadlines and insurance advance payments – and what happens if you miss one.
Overview of deadlines an OSVČ must not miss
As a self-employed person (OSVČ) you juggle several types of deadlines at once – tax, insurance and those relating to the flat-rate regime. This page brings them all together in one place, so none of them slip through your fingers.
You will find the exact advance payment amounts in the overview [Minimum OSVČ advances 2026](/pojisteni-osvc/minimalni-zalohy-2026), and the filing procedure in [OSVČ tax return](/dane-osvc/danove-priznani). Current forms, calculators and payment information are also available from the [Financial Administration](https://www.financnisprava.cz) and [ČSSZ](https://www.cssz.cz).
OSVČ 2026 deadline calendar
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by the 20th of every month next deadlineFlat-rate tax – monthly payment If you are in the flat-rate regime, you pay income tax and both insurance advances together in a single payment. → detail
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by the 25th day after the period ends next deadlineVAT return and VAT control statement Applies to VAT payers and identified persons for months (or quarters) in which a taxable supply occurred. → detail
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by 1 April 2026 next deadlineTax return – paper filing Applies to individuals without a data box (datová schránka) and without a tax adviser. Most OSVČ have a data box set up automatically by law, so this applies only to exceptions.
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by 4 May 2026 next deadlineTax return – electronic filing The standard deadline for OSVČ with a data box (datová schránka), which is set up automatically by law. → detail
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by 1 July 2026 next deadlineTax return – with a tax adviser The condition is a power of attorney filed with the tax office by the end of the basic deadline, i.e. by 4 May 2026.
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roughly 1 month after the tax return next deadlineStatements (přehled) for ČSSZ and your health insurance company These follow the tax return. For electronic filing for 2025, typically ČSSZ by 1 June 2026 and the health insurance company by 4 June 2026. → detail
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by the 8th of the following month next deadlineHealth insurance advance Paid for every month, minimum 3,306 Kč. If the deadline falls on a weekend, it moves to the nearest working day. → detail
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by the end of the current month next deadlineSocial insurance advance Minimum 5,005 Kč from 7/2026 (until 6/2026: 5,720 Kč; starting OSVČ: 3,575 Kč) – due earlier than the health insurance advance. → detail
What happens if you miss a deadline
A missed deadline is almost never an immediate disaster, but the longer you leave the problem unresolved, the more expensive it becomes.
- **Tax return** – a penalty for late filing arises only once the delay exceeds the 5-working-day grace period. It then amounts to 0.05 % of the assessed tax for each day of delay, up to a maximum of 5 % of the tax (and at least 500 Kč if you do not file the return at all). In addition, late-payment interest runs on the tax itself, matching the CNB repo rate increased by 8 percentage points per year (in 2026 roughly 11.5–11.75 % p. a.).
- **Social and health insurance** – for late payment, both ČSSZ and the health insurance company charge a penalty equal to the late-payment interest rate, i.e. the CNB repo rate + 8 percentage points per year (from 7/2026 this is 0.0322 % of the amount owed for each day of delay). For the social insurance advance there is also relief: no penalty is added if you settle it by the end of the following calendar month. Long-term debt can end in enforcement (exekuce) or a demand for payment with interest.
- **Flat-rate tax** – an unpaid flat-rate payment becomes an arrears, which the tax office recovers like any other tax (including late-payment interest); a single forgotten payment usually just needs to be settled as soon as possible. Non-payment alone does not automatically remove you from the flat-rate regime – you fall out of the regime only once you stop meeting its conditions (you exceed your band's income limit, become a VAT payer, etc.), and then you must tax the income via a standard return.
The most common OSVČ mistakes in payments and filings are summarised in the [overview of common mistakes](/dane-osvc/caste-chyby).
Where to go next for exact amounts and procedures
Frequently asked questions about OSVČ deadlines
What happens if I pay the social insurance advance late?
For late payment, ČSSZ charges a penalty equal to the late-payment interest rate – from 7/2026 this is 0.0322 % of the amount owed for each day of delay (the CNB repo rate + 8 percentage points per year). There is some relief for the advance, though: no penalty is added if you settle it by the end of the following calendar month. The advance for the main activity (hlavní činnost) is due by the end of the current month, unlike the health insurance advance, which has a deadline eight days longer. You will find the exact amounts in [minimum OSVČ advances 2026](/pojisteni-osvc/minimalni-zalohy-2026).
Do I have to file a VAT control statement if I am not a VAT payer?
No, the VAT control statement is filed only by VAT payers. An identified person (e.g. when buying services from abroad) files a VAT return only for the months in which a cross-border supply occurred, by the 25th day of the following month. Details are available in [VAT return](/dane-osvc/priznani-k-dph).
By when do I have to file my tax return if I have a data box?
By 4 May 2026. OSVČ have a data box (datová schránka) set up automatically by law, so they must file the return electronically, with the extended deadline – the 1 April paper deadline does not apply to them. You will find the step-by-step procedure in [OSVČ tax return](/dane-osvc/danove-priznani).
When is the flat-rate tax due?
Always by the 20th day of the relevant calendar month, in a single payment to the Financial Administration's account, which covers income tax and both insurance advances. Because of the social insurance reform, the amount of band 1 also changes from July 2026. You will find the current amounts in [flat-rate tax 2026](/dane-osvc/pausalni-dan).
By when must I file the statements (přehled) for ČSSZ and the health insurance company?
The deadline follows the tax return – for electronic filing, roughly one month after it (for 2025, typically ČSSZ by 1 June 2026, the insurance company by 4 June 2026). Details are available in [OSVČ statements](/pojisteni-osvc/prehledy-osvc).