OSVČ Tax Calendar 2026: All Important Deadlines
As an OSVČ, you need to meet dozens of deadlines throughout the year — from insurance advance payments to your tax return and reports for ČSSZ and your health insurance company. Missing even a single deadline can result in an unnecessary fine or penalty. That's why we've put together a complete tax calendar for 2026, covering all key deadlines month by month. We draw exclusively from the official Czech Financial Administration tax calendar and information from the Czech Social Security Administration.
How deadlines work in 2026
If the last day of a deadline falls on a Saturday, Sunday, or public holiday, it is automatically moved to the next working day. This is why many deadlines in 2026 differ from their "standard" dates. For example, 31 January 2026 falls on a Saturday, so those deadlines shift to Monday, 2 February.
Since 2023, all OSVČ have had a data mailbox set up automatically. If yours is activated, you are required to communicate with the tax office exclusively electronically — either via your data mailbox or through the MOJE daně portal.
Overview of Key Deadlines by Type of Obligation
Before diving into the individual months, let's take a look at the overall summary of the main OSVČ obligations and their deadlines in 2026:
📊Overview of Main OSVČ Deadlines 2026
January 2026
January is a critical month for OSVČ — a number of important deadlines fall right at the start of the year.
By 12 January 2026
- Notification of entry into the flat-rate tax regime — if you want to pay flat-rate tax from 2026 onwards, you must notify your tax office no later than 12 January. Anyone who was already in the flat-rate regime in 2025 continues automatically. A change of band must also be notified by this date. More details are available on the Financial Administration website.
By 20 January 2026
- Flat-rate tax advance payment for January 2026. Monthly flat-rate tax amounts for 2026:
| Band | Monthly advance | Annual total | Income limit | |------|----------------|--------------|--------------| | Band 1 | 9,984 CZK | 119,808 CZK | Up to 1,000,000 CZK | | Band 2 | 16,745 CZK | 200,940 CZK | Up to 1,500,000 CZK | | Band 3 | 27,139 CZK | 325,668 CZK | Up to 2,000,000 CZK |
By 26 January 2026
- VAT return and control statement for December 2025 (monthly VAT payers) or for Q4 2025 (quarterly VAT payers). 25 January falls on a Sunday, so the deadline shifts to Monday, 26 January.
By the end of January 2026
- Social insurance advance payment for January 2026 — due by the last day of the month, i.e. Saturday, 31 January. Since 31 January falls on a Saturday, it effectively shifts to Monday, 2 February.
- Income tax advance payment — quarterly advance for Q4 2025 (if your last known tax liability exceeded 150,000 CZK). The 31 January deadline shifts to 2 February.
Minimum insurance advance payments for 2026
From January 2026, minimum insurance advance payments are rising significantly. This is due to an increase in the average wage and a change to the social insurance assessment base, which moves from 35% to 40% of the average wage.
| Insurance | Primary activity | Secondary activity | |-----------|-----------------|-------------------| | Social insurance | 5,720 CZK/month | 1,574 CZK/month | | Health insurance | 3,306 CZK/month | No minimum advance | | Total | 9,026 CZK/month | 1,574 CZK/month |
The new advance amounts must be paid from the month following the submission of your report (i.e. from May or June 2026), unless your report for 2025 results in a higher advance payment.
Sources: ČSSZ – insurance advance payments, VZP – 2026 payments
February 2026
By 2 February 2026
- Real estate tax return for 2026 — only required if you acquired a property in 2025 (purchase, inheritance, gift) or if there was a change affecting the amount of tax. More details on the Financial Administration website. The standard 31 January deadline shifts due to the Saturday.
- Road tax return for 2025 and simultaneous road tax payment — applies only to operators of freight vehicles over 12 tonnes. Must be submitted exclusively electronically via the MOJE daně portal.
By 8 February 2026
- Health insurance advance payment for January 2026. Health insurance is due from the 1st day of the calendar month to the 8th day of the following month. 8 February falls on a Sunday, so it shifts to 9 February.
By 20 February 2026
- Flat-rate tax advance payment for February 2026.
By 25 February 2026
- VAT return and control statement for January 2026 (monthly VAT payers).
By 28 February 2026
- Social insurance advance payment for February 2026.
March 2026
By 9 March 2026
- Health insurance advance payment for February 2026. 8 March falls on a Sunday.
By 20 March 2026
- Flat-rate tax advance payment for March 2026.
By 25 March 2026
- VAT return and control statement for February 2026 (monthly VAT payers).
By 31 March 2026
- Social insurance advance payment for March 2026.
April 2026
April is one of the most important months for OSVČ — tax return deadlines fall here.
By 1 April 2026
- Personal income tax return for 2025 (paper submission) — this deadline applies to OSVČ who do not have an activated data mailbox and are submitting their return on paper. This is also the deadline for paying any outstanding tax liability.
Important: Mandatory electronic filing
Practically all OSVČ have had a data mailbox set up automatically since 2023. If your data mailbox is activated, you must submit your return electronically — either via your data mailbox or through the MOJE daně portal. Submitting on paper when electronic filing is required can result in a fine of 1,000 CZK. Electronic submission also gives you an extra month (until 4 May). You can check the status of your data mailbox at info.mojedatovaschranka.cz.
By 8 April 2026
- Health insurance advance payment for March 2026.
By 15 April 2026
- Income tax advance payment — semi-annual advance (if your last known tax liability exceeded 30,000 CZK but did not exceed 150,000 CZK). The payment is 40% of the last known tax liability.
By 20 April 2026
- Flat-rate tax advance payment for April 2026.
By 27 April 2026
- VAT return and control statement for March 2026 (monthly VAT payers) or for Q1 2026 (quarterly VAT payers). 25 April is a Saturday, so it shifts to 27 April (Monday).
By 30 April 2026
- Social insurance advance payment for April 2026.
May 2026
By 4 May 2026
This is one of the busiest days of the year for OSVČ:
- Personal income tax return for 2025 (electronic submission) — 2 May falls on a Saturday, so the deadline shifts to Monday, 4 May. This is also the deadline for paying any outstanding tax liability.
- Report on income and expenditure for ČSSZ for 2025 — if you submitted your tax return by 1 April.
- Report on income and expenditure for your health insurance company for 2025 — same deadline.
New in 2026: Mandatory electronic submission of health insurance reports
From 2026, all OSVČ must submit reports to their health insurance company exclusively electronically — even if they do not have a data mailbox. This is a significant change compared to previous years.
By 8 May 2026
- Health insurance advance payment for April 2026.
- Supplementary insurance payment for both social and health insurance for 2025 — due within 8 days of actually submitting the report.
By 20 May 2026
- Flat-rate tax advance payment for May 2026.
By 25 May 2026
- VAT return and control statement for April 2026 (monthly VAT payers).
By 31 May 2026
- Social insurance advance payment for May 2026.
- Real estate tax payment — first instalment (or the full amount if it does not exceed 5,000 CZK).
June 2026
By 1 June 2026
- Income tax refund — if you submitted your return and refund request by 1 April, the tax authority will return the overpayment within 30 days of the last day of the deadline. For electronic submissions by 4 May, the refund is returned by 4 June.
By 4 June 2026
- Report on income and expenditure for ČSSZ for 2025 — if you submitted your tax return electronically after 1 April (by 4 May).
- Report on income and expenditure for your health insurance company for 2025 — same deadline.
By 8 June 2026
- Health insurance advance payment for May 2026.
By 15 June 2026
- Income tax advance payment — semi-annual advance (for tax liability of 30,000–150,000 CZK) or quarterly advance (for tax liability above 150,000 CZK).
By 20 June 2026
- Flat-rate tax advance payment for June 2026.
By 25 June 2026
- VAT return and control statement for May 2026 (monthly VAT payers).
By 30 June 2026
- Social insurance advance payment for June 2026.
July 2026
By 1 July 2026
- Personal income tax return for 2025 (via a tax advisor) — the power of attorney for the tax advisor must be delivered to the tax office before the standard filing deadline expires.
By 8 July 2026
- Health insurance advance payment for June 2026.
By 20 July 2026
- Flat-rate tax advance payment for July 2026.
By 27 July 2026
- VAT return and control statement for June 2026 (monthly VAT payers) or for Q2 2026 (quarterly VAT payers). 25 July is a Saturday, so it shifts to 27 July.
By 31 July 2026
- Social insurance advance payment for July 2026.
August 2026
By 3 August 2026
- Report on income and expenditure for ČSSZ for 2025 — if you submitted your tax return via a tax advisor (by 1 July). 1 August is a Saturday, so it shifts to 3 August.
- Report on income and expenditure for your health insurance company for 2025 — same deadline.
By 8 August 2026
- Health insurance advance payment for July 2026.
By 20 August 2026
- Flat-rate tax advance payment for August 2026.
By 25 August 2026
- VAT return and control statement for July 2026 (monthly VAT payers).
By 31 August 2026
- Social insurance advance payment for August 2026.
September 2026
By 8 September 2026
- Health insurance advance payment for August 2026.
By 15 September 2026
- Income tax advance payment — quarterly advance (only for tax liability above 150,000 CZK).
By 21 September 2026
- Flat-rate tax advance payment for September 2026. 20 September is a Sunday, so it shifts to 21 September.
By 25 September 2026
- VAT return and control statement for August 2026 (monthly VAT payers).
By 30 September 2026
- Social insurance advance payment for September 2026.
October 2026
By 8 October 2026
- Health insurance advance payment for September 2026.
By 20 October 2026
- Flat-rate tax advance payment for October 2026.
By 26 October 2026
- VAT return and control statement for September 2026 (monthly VAT payers) or for Q3 2026 (quarterly VAT payers). 25 October is a Sunday, so it shifts to 26 October.
By 31 October 2026
- Social insurance advance payment for October 2026.
Registering for flat-rate tax for 2027
If you are considering entering the flat-rate tax regime for 2027, you can submit your application from October 2026. The final notification deadline is traditionally in early January. Keep an eye on the latest information on the Financial Administration website.
November 2026
By 9 November 2026
- Health insurance advance payment for October 2026. 8 November is a Sunday.
By 20 November 2026
- Flat-rate tax advance payment for November 2026.
By 25 November 2026
- VAT return and control statement for October 2026 (monthly VAT payers).
By 30 November 2026
- Social insurance advance payment for November 2026.
- Real estate tax payment — second instalment (for tax exceeding 5,000 CZK).
December 2026
By 1 December 2026
- Income tax advance payment — semi-annual advance (for tax liability of 30,000–150,000 CZK) or quarterly advance (for tax liability above 150,000 CZK). Note: the standard semi-annual advance is due by 15 December.
By 8 December 2026
- Health insurance advance payment for November 2026.
By 15 December 2026
- Income tax advance payment — semi-annual (40% of the last known tax liability) or quarterly (25% of the last known tax liability).
By 21 December 2026
- Flat-rate tax advance payment for December 2026. 20 December is a Sunday, so it shifts to 21 December.
By 28 December 2026
- VAT return and control statement for November 2026 (monthly VAT payers). 25 December is a public holiday (Christmas), 26 December is also a public holiday, 27 December is a Sunday — so the deadline shifts to Monday, 28 December.
By 31 December 2026
- Social insurance advance payment for December 2026.
Overview of Regular Monthly Obligations
Some obligations recur every month. Here is a summary:
📊Monthly OSVČ Obligations
Important: Social vs. health insurance — difference in due dates
Watch out for the different due dates:
- Social insurance (ČSSZ): the advance for a given month is due by the end of that same month (e.g. the March advance is due by 31 March).
- Health insurance: the advance for a given month is due from the 1st of that month to the 8th of the following month (e.g. the March advance is due between 1 March and 8 April).
Don't mix these up — late payment results in penalties.
Income Tax Advance Payments — When and How Much
Whether you need to pay income tax advances depends on your last known tax liability:
| Last known tax liability | Advance payments | Deadlines | Amount | |--------------------------|-----------------|-----------|--------| | Up to 30,000 CZK | No advance payments required | – | – | | 30,001 – 150,000 CZK | Semi-annual (twice a year) | 15 June and 15 December | 40% of tax liability | | Above 150,000 CZK | Quarterly (four times a year) | 15 March, 15 June, 15 September, 15 December | 25% of tax liability |
Example: Income tax advance payments
Scenario: Your tax liability for 2025 was 85,000 CZK.
- You fall into the 30,001 – 150,000 CZK band = semi-annual advance payments
- Advance amount: 85,000 × 40% = 34,000 CZK
- You pay the advance twice a year: by 15 June and by 15 December 2026
- Total advance payments for 2026: 68,000 CZK
VAT — Deadlines for VAT Payers
If you are registered for VAT, you have the following additional obligations:
Monthly VAT Payers
You submit your VAT return and control statement by the 25th of the following calendar month. Specific deadlines for 2026:
| Period | Submission deadline | |--------|-------------------| | January 2026 | 25 February 2026 | | February 2026 | 25 March 2026 | | March 2026 | 27 April 2026 (25 April is a Saturday) | | April 2026 | 25 May 2026 | | May 2026 | 25 June 2026 | | June 2026 | 27 July 2026 (25 July is a Saturday) | | July 2026 | 25 August 2026 | | August 2026 | 25 September 2026 | | September 2026 | 26 October 2026 (25 October is a Sunday) | | October 2026 | 25 November 2026 | | November 2026 | 28 December 2026 (25 December is a public holiday) | | December 2026 | 25 January 2027 |
Quarterly VAT Payers
| Period | Submission deadline | |--------|-------------------| | Q1 2026 | 27 April 2026 | | Q2 2026 | 27 July 2026 | | Q3 2026 | 26 October 2026 | | Q4 2026 | 25 January 2027 |
VAT control statements for OSVČ
Unlike legal entities, which submit control statements every month, OSVČ submit control statements at the same frequency as their VAT return — i.e. monthly or quarterly depending on their tax period. The control statement must be submitted exclusively electronically in XML format. More details on the Financial Administration website.
Flat-Rate Tax 2026 — What You Need to Know
The flat-rate tax is a simplified scheme where a single monthly payment covers your income tax, social insurance, and health insurance. In 2026, the monthly payment for Band 1 is increasing.
📊Flat-Rate Tax 2026 — Breakdown of Monthly Payment (Band 1)
Conditions for the flat-rate tax regime:
- Annual income up to 2,000,000 CZK
- Not a VAT payer
- No employees
- No employment income (with the exception of income taxed at source by withholding tax)
Flat-rate tax advance payments are due by the 20th of each calendar month.
Penalties for Missing Deadlines
If you're running late, it's important to know what penalties may apply:
| Situation | Penalty | |-----------|---------| | Filing within 5 working days of the deadline | No fine (grace period) | | Filing after 5 working days | 0.05% of tax per day of delay (max. 5% or 300,000 CZK) | | Late tax payment | Late payment interest: Czech National Bank repo rate + 8 percentage points | | Failure to submit VAT control statement | 10,000 – 50,000 CZK | | Paper submission when electronic filing is required | 1,000 CZK | | Late payment of insurance advance payments | Penalties per ČSSZ/health insurance rules |
📋5 tips to never miss a deadline
How DokladBot Keeps Track of Your Deadlines
Keeping track of dozens of deadlines throughout the year is no easy feat. DokladBot helps by automatically sending you reminders before every important deadline directly to your WhatsApp. You don't need to monitor anything — DokladBot will alert you in good time so you have plenty of time to prepare and submit.
DokladBot: Your personal tax assistant on WhatsApp
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- Upcoming tax return filing deadlines
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Frequently Asked Questions
What happens if a deadline falls on a weekend?
If the last day of a deadline falls on a Saturday, Sunday, or public holiday, it is automatically moved to the next working day. This rule applies to all tax obligations.
Do I have to pay insurance advance payments even if I have no income?
If you carry out a primary business activity, you must pay at least the minimum advance payments regardless of your income. For a secondary activity, social insurance advance payments only become due from the month indicated in your report, and there are no minimum health insurance advances.
How do I find my tax office and the account number for paying tax?
Your local tax office is determined by your permanent address. Account numbers for paying individual taxes can be found on the Financial Administration website.
When will the tax authority refund an overpayment?
The tax authority will return an overpayment within 30 days of the last day of the filing deadline, provided you submit a refund request (simply tick the relevant box on your return). If you file by 1 April, the refund is returned by early May; if you file electronically by 4 May, the refund is returned by early June.
Do I have to pay flat-rate tax advances in the month I start my business?
Yes, the flat-rate tax advance is also due for the month in which you entered the flat-rate regime. It is always due by the 20th of the relevant month.
This article is based on the official Czech Financial Administration tax calendar, information from ČSSZ, and data from VZP. The information is accurate as of the publication date and may change as a result of legislative updates.
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