The dates that matter most to a Czech sole trader in 2026: 1 April for filing the personal income tax return on paper, 4 May for filing it electronically (moved from 1 May because of the public holiday), and 1 July if a tax adviser files it for you. The 20th of each month is the flat tax payment. The 25th of the month after each period covers the VAT return and the control report. 15 June and 15 December are the income tax advance dates.
One rule applies throughout: if a deadline falls on a Saturday, a Sunday or a public holiday, it moves to the next working day.
January 2026
By 12 January (Monday)
- Notice of entry into the flat-tax regime for 2026 — the statutory date of 10 January falls on a Saturday, so it moves to Monday 12 January
- Flat tax payment for January — by 20 January (and by the 20th of every month after that)
By 25 January (a Sunday, so the deadline moves to 26 January)
- VAT return for December 2025 (monthly payers) — form DPHDP3, filed electronically through EPO
- VAT return for Q4 2025 (quarterly payers) — form DPHDP3
- Control report for December 2025 (monthly payers) — form DPHKH1
- Control report for Q4 2025 (quarterly payers, which covers most sole traders) — form DPHKH1
- VAT for December 2025 or Q4 2025 falls due
January is traditionally the heaviest month. You close the previous year and file your last VAT return for 2025. It is worth starting to gather the paperwork in the first week of January.
February 2026
By 25 February (Wednesday)
- VAT return for January 2026 (monthly payers)
- Control report for January 2026 (monthly payers)
- VAT for January 2026 falls due
February is also when your health insurer and the district social security office send you the figures used to calculate last year's contributions. Start collecting what you need for the income tax return.
March 2026
By 15 March (a Sunday, so the deadline moves to 16 March)
- Quarterly income tax advance, if your last known tax liability exceeded 150,000 CZK
By 25 March (Wednesday)
- VAT return for February 2026 (monthly payers)
- Control report for February 2026 (monthly payers)
- VAT for February 2026 falls due
March is the last month to prepare your personal income tax return. If you are filing on paper, the deadline is 1 April.
April 2026
By 1 April (Wednesday)
- Personal income tax return for 2025 (paper filing) — form DPFDP7
By 25 April (a Saturday, so the deadline moves to 27 April)
- VAT return for March 2026 (monthly payers)
- VAT return for Q1 2026 (quarterly payers)
- Control report for March 2026 (monthly payers)
- Control report for Q1 2026 (quarterly payers)
- VAT for March or Q1 2026 falls due
April is the busiest month in the calendar. If you file the income tax return yourself, without a tax adviser, the paper version has to be in by 1 April.
May 2026
4 May 2026 — the electronic filing deadline
The deadline for filing the 2025 personal income tax return electronically is 4 May 2026. The statutory period is four months after the end of the tax period, which would be 1 May — but that is a public holiday, and 2 and 3 May fall on the weekend, so the deadline moves to Monday 4 May. The paper deadline was 1 April 2026 (a Wednesday).
- Personal income tax return for 2025 (filed electronically through EPO) — form DPFDP7
- Annual statements of income and expenses (přehled) for 2025 for the social security administration and your health insurer — if you filed the tax return by 1 April (the statements are due within one month of the return deadline)
By 25 May (Monday)
- VAT return for April 2026 (monthly payers)
- Control report for April 2026 (monthly payers)
- VAT for April 2026 falls due
Filing electronically gives you a month more than filing on paper. If you use a datová schránka (data box) or EPO, the 2025 return is due on 4 May. It is worth taking that route: it is quicker, more convenient, and buys you the extra month.
June 2026
By 2 June (Tuesday)
- Annual statement of income and expenses for ČSSZ for 2025 — if you filed the tax return electronically after 1 April
By 4 June (Thursday)
- Annual statement of income and expenses for your health insurer for 2025 — if you filed the tax return electronically after 1 April
By 15 June (Monday)
- Income tax advance — both the half-yearly (40%) and the quarterly (25%) advance, if your last known tax liability exceeded 30,000 CZK
By 25 June (Thursday)
- VAT return for May 2026 (monthly payers)
- Control report for May 2026 (monthly payers)
- VAT for May 2026 falls due
July 2026
By 1 July (Wednesday)
- Personal income tax return for 2025 filed by a tax adviser — if you have given an adviser power of attorney, the deadline is 1 July
By 25 July (a Saturday, so the deadline moves to 27 July)
- VAT return for June 2026 (monthly payers)
- VAT return for Q2 2026 (quarterly payers)
- Control report for June 2026 (monthly payers)
- Control report for Q2 2026 (quarterly payers)
- VAT for June or Q2 2026 falls due
August 2026
By 3 August (Monday)
- Annual statements for 2025 for the social security administration and your health insurer — if a tax adviser filed your return (within one month of the 1 July deadline; 1 August is a Saturday)
By 25 August (Tuesday)
- VAT return for July 2026 (monthly payers)
- Control report for July 2026 (monthly payers)
- VAT for July 2026 falls due
September 2026
By 15 September (Tuesday)
- Quarterly income tax advance, if your last known tax liability exceeded 150,000 CZK
By 25 September (Friday)
- VAT return for August 2026 (monthly payers)
- Control report for August 2026 (monthly payers)
- VAT for August 2026 falls due
October 2026
By 25 October (a Sunday, so the deadline moves to 26 October)
- VAT return for September 2026 (monthly payers)
- VAT return for Q3 2026 (quarterly payers)
- Control report for September 2026 (monthly payers)
- Control report for Q3 2026 (quarterly payers)
- VAT for September or Q3 2026 falls due
November 2026
By 25 November (Wednesday)
- VAT return for October 2026 (monthly payers)
- Control report for October 2026 (monthly payers)
- VAT for October 2026 falls due
December 2026
By 15 December (Tuesday)
- Income tax advance, if your 2025 tax liability exceeded 30,000 CZK — half-yearly advances fall due on 15 June and 15 December, quarterly advances on 15 March, 15 June, 15 September and 15 December
By 25 December (a Friday and a public holiday; 26 and 27 December are the weekend, so the deadline moves to Monday 28 December)
- VAT return for November 2026 (monthly payers)
- Control report for November 2026 (monthly payers)
- VAT for November 2026 falls due
Note that the December VAT return — for December 2026 and for Q4 2026 — is not filed until January 2027.
Obligations that run through the year
Social security advances
A sole trader pays monthly social security advances to the relevant district social security office. An advance is payable from the 1st to the last day of the month it relates to, so the January advance is due by 31 January. The 2026 minimum advance is 5,005 CZK: amendment No. 90/2026 Coll. lowered it with retroactive effect from 1 January 2026 (5,720 CZK was paid for January to June; the overpayment of 6 × 715 = 4,290 CZK is refunded or set off against future advances).
Health insurance advances
Monthly health insurance advances go to your health insurer and are due by the 8th day of the following month. The 2026 minimum advance is 13.5% of half the average wage.
Flat tax payment
A sole trader in the flat-tax regime pays a single monthly amount (tax plus social and health insurance) by the 20th of each month. In band I it is 9,162 CZK from July 2026 (with retroactive effect from 1 January 2026; 9,984 CZK was paid for January to June and the overpayment is set off against future payments), 16,745 CZK in band II and 27,139 CZK in band III.
Income tax advances
If your last known tax liability exceeded 30,000 CZK, you pay advances on income tax:
- 30,001–150,000 CZK: half-yearly advances of 40% of the last known tax, due by 15 June and 15 December
- above 150,000 CZK: quarterly advances of 25% of the last known tax, due by 15 March, 15 June, 15 September and 15 December
Penalties for filing or paying late
Missing a deadline has real consequences.
Income tax return
- Late filing penalty: 0.05% of the assessed tax for each day of delay, capped at 5% of the tax and at 300,000 CZK — Section 250 of the Tax Code. The penalty is not assessed if it does not exceed 1,000 CZK; the 500 CZK minimum applies only if you fail to file even after being asked by the tax administrator.
- Tolerance: 5 working days. File within 5 working days of the deadline and no penalty is imposed.
Control report
- 1,000 CZK — filed late without being prompted by the tax administrator
- 10,000 CZK — filed within the substitute period after the tax administrator asks for it
- 30,000 CZK — not filed in response to a request to change, add or confirm data
- 50,000 CZK — not filed even within the substitute period
For individuals and quarterly payers the 10,000, 30,000 and 50,000 CZK fines have been halved since 2023 — 5,000, 15,000 and 25,000 CZK.
Interest on late payment
Interest on late payment of tax runs at the ČNB repo rate plus 8 percentage points a year, charged for each day of delay from the 4th day after the due date — Section 252(2) of the Tax Code, where the tolerance is 3 calendar days, not working days. Interest is not assessed if it does not exceed 1,000 CZK.
How Taxorio helps with deadlines
Taxorio has a built-in tax calendar that shows the dates relevant to you, based on your settings: whether you are VAT registered and whether you file monthly or quarterly.
Colour-coded urgency
Deadlines are distinguished by colour:
- red — the deadline is within a week, so it needs attention now
- amber — the deadline is within two weeks; time to prepare
- blue — the deadline is further out, shown for information
The tax calendar sits on the dashboard as a card, so the next deadlines are in front of you as soon as you sign in.
VAT exports in one click
For VAT payers on the PRO plan, Taxorio generates the XML files for the control report (DPHKH1) and the VAT return (DPHDP3), ready to submit through the Financial Administration's EPO. There is nothing to retype: the system takes your invoices and expenses for the period.
Income tax
For the personal income tax return, the PRO plan offers the DPFDP7 export in XML. Every user, on any plan, has the CSV book of income and expenses, which is the basis for filling the return in.
Let Taxorio keep track of the dates for you. Register free at app.taxorio.cz and keep the tax calendar to hand.
Taxorio scope: Taxorio provides invoicing and income/expense records for Czech sole traders. It is not full accounting or personalised tax advice. For an unsupported or unusual case, verify the treatment with a Czech accountant or tax adviser before filing.