Self-Employed Tax Return 2026: Complete Step-by-Step Guide

Anyone who was self-employed (OSVČ) in 2025 must file a personal income tax return. It doesn't matter whether you earned a million or ended up at a loss — the obligation to file applies to virtually all self-employed individuals. This guide will walk you through the entire process: from gathering your documents and calculating your tax correctly, all the way to submitting your return electronically to the tax authority. All information is based on current legislation, with direct links to official Czech Tax Administration forms.

Key deadlines for filing your tax return in 2026

The deadline by which you must file your tax return depends on your chosen method of submission. This is also the deadline by which any outstanding tax must be paid.

| Filing method | Filing and payment deadline | Notes | |---------------|---------------------------|----------| | Paper filing | 1 April 2026 | Only if your data mailbox has not been activated | | Electronic filing (data mailbox / MOJE daně portal) | 4 May 2026 | 2 May 2026 falls on a Saturday, so the deadline shifts to Monday | | Via a tax advisor | 1 July 2026 | A power of attorney for the tax advisor must be delivered to the tax office before the standard deadline expires |

Deadlines for ČSSZ and health insurance company statements

After filing your tax return, you are also required to submit income and expenditure statements to the Czech Social Security Administration (ČSSZ) and your health insurance company. The deadline depends on when you filed your tax return:

| Situation | Statement for ČSSZ | Statement for health insurance company | |---------|-------------|------------| | Return filed by 1 April 2026 | 4 May 2026 | 4 May 2026 | | Return filed electronically by 4 May 2026 | 4 June 2026 | 4 June 2026 | | Return filed via a tax advisor | 3 August 2026 | 3 August 2026 |

You can submit the ČSSZ statement electronically at the ČSSZ ePortal. The health insurance statement is submitted through your specific insurer's portal — for example VZP or OZP.

2026 update: Starting this year, all OSVČ must submit their health insurance statements exclusively electronically — even if they do not have a data mailbox.

What forms you will need

Before you start filling anything in, make sure you have the right forms. All are available electronically on the MOJE daně portal in the EPO (Electronic Submissions) section, or as downloadable PDFs on the Tax Administration website.

| Form | Form number | When you need it | Download | |----------|----------------|-----------------|------------| | Personal Income Tax Return (main form) | 25 5405 | Always — this is the core form | PDF form | | Appendix 1 — self-employment income | 25 5405/P1 | Virtually all OSVČ — calculates the partial tax base under § 7 of the Income Tax Act | PDF appendix | | Appendix 2 — employment income | 25 5405/P2 | If you have employment income in addition to self-employment (§ 6 of the Income Tax Act) | — | | Appendix 3 — foreign income | 25 5405/P3 | If you have income from sources abroad (§ 38f of the Income Tax Act) | — |

How income tax is calculated for OSVČ — step by step

Calculating your income tax involves several sequential steps. Let's go through each one so you know exactly how you arrive at the final amount.

Step 1: Determine your tax base

Tax base = self-employment income − expenses

You can claim expenses in one of two ways — either as a flat-rate percentage of your income, or at their actual amount based on your bookkeeping records.

A) Flat-rate expenses — you apply a percentage of your income without needing to document individual expense receipts:

| Type of business activity | Percentage of income | Maximum annual amount | |---------------------------|-------------------|----------------------| | Trade crafts, agricultural production, forestry and water management | 80% | 1,600,000 CZK | | Licensed trade businesses (free, restricted, and licensed trades) | 60% | 1,200,000 CZK | | Other self-employed activity without a trade licence (authors, doctors, lawyers, expert witnesses) | 40% | 800,000 CZK | | Income from rental of assets included in business property | 30% | 600,000 CZK |

B) Actual expenses — you claim only those expenses that are documented in your bookkeeping records (income and expenditure ledger, bank statements, receipts). This approach pays off if you have high operating costs — rent, materials, employees.

Step 2: Deduct non-taxable portions of the tax base

Before calculating the actual tax, you can deduct so-called non-taxable items from your tax base. This reduces the amount on which the tax is calculated:

| Item | Maximum annual deduction | Conditions | |---------|------------------------|----------| | Mortgage or housing loan interest | 150,000 CZK (housing acquired after 1 January 2021) / 300,000 CZK (before 1 January 2021) | You must have a bank confirmation of interest paid | | Pension savings (supplementary pension savings, pension insurance) | 48,000 CZK | The deduction applies to contributions exceeding 1,700 CZK per month | | Life insurance | 48,000 CZK | The policy must meet statutory requirements (minimum 60-month term, payout no earlier than age 60) | | Long-term care insurance | 14,400 CZK | New deduction introduced in 2024 | | Donations to public benefit causes | Min. 1,000 CZK or 2% of the tax base; max. 30% of the tax base | You must have a confirmation from the recipient | | Blood donation | 3,000 CZK per donation | Confirmation from the transfusion centre | | Bone marrow / stem cell donation | 20,000 CZK per donation | Confirmation from the medical facility | | Trade union membership fees | 3,000 CZK per year | Confirmation from the trade union |

Step 3: Calculate the tax

From the reduced tax base (after deducting non-taxable items), you calculate tax using the rates applicable for 2025:

| Band | Tax rate | Tax base range | |-------|-----------|-------------------| | 1st band | 15% | Up to 1,676,052 CZK (36 times the average wage of 46,557 CZK) | | 2nd band | 23% | On the portion of the tax base exceeding 1,676,052 CZK |

Taxation is progressive — the 23% rate applies only to the amount that exceeds the first band threshold. So if an OSVČ has a tax base of 2,000,000 CZK, the 15% rate applies to the first 1,676,052 CZK and the 23% rate only to the remaining 323,948 CZK.

Step 4: Apply tax credits

Tax credits are deducted directly from the calculated tax (not from the tax base). This is a key difference from the non-taxable items in the previous step. The basic personal tax credit is applied automatically:

| Tax credit | Annual amount | Conditions | |--------------|-------------|----------| | Personal tax credit (basic) | 30,840 CZK | Automatic, applies to every taxpayer | | Spouse credit | 24,840 CZK | Spouse's income must not exceed 68,000 CZK per year, and they must be caring for a child under 3 | | Spouse credit with ZTP/P disability card | 49,680 CZK | Double the standard credit | | Disability — grade I or II | 2,520 CZK | Confirmation of disability pension award | | Disability — grade III | 5,040 CZK | Confirmation of disability pension award | | ZTP/P disability card holder | 16,140 CZK | Copy of ZTP/P card |

Note — abolished credits: As of 2024 (the consolidation package), the student tax credit (previously 4,020 CZK) and the nursery/kindergarten credit (previously up to 17,300 CZK) were abolished. These credits can no longer be claimed.

Step 5: Apply the child tax credit

The child tax credit for dependent children is the most important item for families with children. The amount depends on the child's birth order:

| Dependent child | Annual credit | Monthly credit | |----------------|-----------------|-------------------| | 1st child | 15,204 CZK | 1,267 CZK | | 2nd child | 22,320 CZK | 1,860 CZK | | 3rd and each additional child | 27,840 CZK | 2,320 CZK |

For a child holding a ZTP/P disability card, the credit amount is doubled.

Tax bonus: If your child tax credit exceeds your calculated tax (after applying credits), you receive a tax bonus — the government pays you the difference directly into your account. To be eligible for the tax bonus, your annual income must be at least 124,800 CZK (six times the minimum monthly wage of 20,800 CZK).

Important restriction: If you claim flat-rate expenses, you cannot simultaneously claim the child tax credit in the form of a tax bonus. The credit can only be applied up to the amount of your calculated tax, or it can be claimed by the other parent instead.

Practical steps for filing your tax return

What to prepare before you start filling in the form

To complete your return smoothly without having to stop and search for documents, prepare the following in advance:

• Bank account statement for the entire year 2025 (business income and expenses)
• Invoice summary — issued invoices (income) and received invoices (expenses)
• Confirmations of advance payments made for social insurance to ČSSZ and for health insurance to your insurer
• Bank confirmation of mortgage interest paid (if claiming the deduction)
• Pension savings confirmation from your pension company
• Life insurance confirmation from your insurer
• Donation confirmations from recipients (if claiming the deduction)
• Children's birth certificates (if claiming the child tax credit) and proof of full-time study for children over 18

Social and health insurance for OSVČ — how much will you pay

In addition to income tax, as an OSVČ you also pay social security contributions (pension insurance) and public health insurance. Contributions are calculated from your assessment base, which is derived from your tax base.

How contributions are calculated

• Social insurance assessment base: 55% of the tax base under § 7 of the Income Tax Act
• Health insurance assessment base: 50% of the tax base under § 7 of the Income Tax Act
• Social insurance rate: 29.2% of the assessment base
• Health insurance rate: 13.5% of the assessment base
• Maximum assessment base (social insurance): 2,234,736 CZK (48 times the average wage); health insurance has no maximum

Secondary activity threshold: If you operated as an OSVČ with secondary activity in 2025, you only pay social insurance if your annual profit (tax base) exceeded 111,736 CZK. Below this threshold, no social insurance contributions are due at all.

Flat-rate tax — a simpler alternative for smaller OSVČ

If you'd rather not deal with filing a tax return or insurance statements, you can opt for the flat-rate tax regime (paušální daň). A single monthly payment covers your income tax, social insurance, and health insurance. You are not required to file a tax return, a ČSSZ statement, or a health insurance statement.

Full details are available on the Tax Administration website — flat-rate tax.

Monthly payments by band (2025)

| Band | Monthly payment | Total annual payment | Annual income limit | |-------|---------------|--------------------|--------------------| | Band 1 | 8,716 CZK | 104,592 CZK | Up to 1,000,000 CZK | | Band 2 | 16,745 CZK | 200,940 CZK | Up to 1,500,000 CZK (or 2,000,000 CZK if at least 75% of income comes from activities eligible for a 60%+ flat-rate expense deduction) | | Band 3 | 27,139 CZK | 325,668 CZK | Up to 2,000,000 CZK |

Conditions for enrolling in the flat-rate tax regime

• You are not a VAT payer (and did not become one during the year)
• Your annual self-employment income did not exceed 2,000,000 CZK
• You have no employment income, except for income taxed at source by withholding tax
• You are not in insolvency proceedings
• You are not a partner in a general commercial partnership or a general partner in a limited partnership

The 10 most common mistakes in OSVČ tax returns

These are the mistakes we see most often. Avoid them and save yourself trouble with the tax office:

1. Wrong flat-rate expense percentage — You apply the 80% rate instead of the correct 60% for your trade licence. The tax office will issue additional tax and penalties upon review.
2. Missing Appendix 1 — A return without the appendix for self-employment income is incomplete, and the tax office will ask you to supplement it.
3. Unclaimed credits and deductions — You forget the personal tax credit, mortgage interest deduction, or pension savings deduction. You end up paying more than you need to.
4. Paper filing instead of electronic — You have a data mailbox but submit on paper. Automatic fine of 1,000 CZK.
5. Advance tax payments not recorded — You fail to enter the advance payments you already made during the year. This results in a falsely inflated underpayment.
6. Incorrect insurance assessment base — An error in the tax return automatically carries over into the ČSSZ and health insurance statements.
7. Overlooked secondary income — You fail to include rental income, one-off project fees, or royalties.
8. Late filing without a valid excuse — After the 5-working-day grace period, a penalty of 0.05% per day of the calculated tax starts accruing.
9. Wrong bank account for overpayment — You enter an incorrect account number and the overpayment is never returned to you.
10. Confusing non-taxable deductions with tax credits — Non-taxable items (mortgage, pension) are deducted from the tax base; credits (personal, children) are deducted from the calculated tax.

Penalties for late filing and late payment

If you file your return or pay your tax after the deadline, you face penalties. The good news is that there is a five-working-day grace period with no fine:

| Situation | Penalty | |---------|--------| | Filed within 5 working days of the deadline | No fine — penalty-free grace period | | Filed within 30 days of the deadline (and not a repeat offence) | 0.025% of the tax per day of delay (half rate) | | Filed after 30 days | 0.05% of the tax per day of delay | | Maximum penalty | 5% of the assessed tax, up to 300,000 CZK | | Penalty below 1,000 CZK | Not levied | | Late payment interest for overdue tax | Czech National Bank repo rate + 8 percentage points (currently approx. 11.75% p.a.), calculated from the 4th day after the due date |

How DokladBot makes preparing your tax return easier

The hardest part of filing a tax return isn't filling in the form itself — it's keeping track of your income and expenses throughout the year. That's exactly where DokladBot comes in: an AI bookkeeping assistant built right into WhatsApp:

• Ongoing expense tracking — You take a photo of a receipt or invoice, send it to WhatsApp, and DokladBot automatically reads and records it. Your document is logged in 5 seconds.
• Your overview, whenever you need it — Just ask "How much have I earned this year?" and DokladBot replies instantly with a precise breakdown of your income and expenses.
• Export ready for your tax return — At year end, you download a complete income and expense summary ready to use when filling in your tax return.
• Deadline reminders — DokladBot alerts you in advance of upcoming deadlines for filing your return, submitting statements, and paying instalments.
• VAT turnover monitoring — It tracks your turnover and warns you when you're approaching the 2,000,000 CZK threshold for mandatory VAT registration.

Frequently asked questions (FAQ)

Do I have to file a tax return even if I made a loss?

Yes. You must file a tax return even if you ended up at a loss or had zero profit. The upside is that you can carry a tax loss forward and deduct it from your tax base over the following 5 tax periods — so filing even with a loss can pay off down the line.

Where can I find the tax return forms?

All current forms are available on the MOJE daně portal in the EPO section (recommended for electronic completion and submission) or as downloadable PDFs on the Tax Administration website. The main personal income tax return form carries the number 25 5405.

How do I know if I need to pay advance tax payments?

You pay advance income tax if your most recent known tax liability exceeded 30,000 CZK. If your tax was between 30,001 and 150,000 CZK, you pay twice a year (40% of the last known tax by 15 June and 15 December). If your tax exceeded 150,000 CZK, you pay quarterly (25% by 15 March, 15 June, 15 September, and 15 December).

Is it worth hiring a tax advisor?

Having a tax advisor prepare an OSVČ tax return typically costs between 3,000 and 8,000 CZK. It's worth it if your situation is more complex — a combination of self-employment and employment income, foreign income, VAT obligations, or if you want to take advantage of the extended filing deadline until 1 July. The advisor also bears responsibility for the accuracy of the return.

Can I be both an employee and self-employed at the same time?

Yes. In that case, your self-employed activity is treated as a secondary activity. Your employment income goes in Appendix 2 (§ 6 of the Income Tax Act) and your self-employment income in Appendix 1 (§ 7 of the Income Tax Act). More favourable secondary-activity rules apply to social insurance contributions (lower minimum advance payments, income threshold).

What is the child tax bonus and how do I get it?

A tax bonus arises when your child tax credit exceeds your calculated tax after applying all other credits. In that case, the government pays you the difference directly into your bank account. The condition is annual income of at least 124,800 CZK. Important: if you claim flat-rate expenses, you cannot receive the tax bonus — the credit can only be applied up to the amount of your tax liability.

Where do I submit the statement for ČSSZ and my health insurance company?

The ČSSZ statement is submitted electronically at the ČSSZ ePortal. The health insurance statement is submitted through your insurer's online portal — for example VZP, OZP, and others.

Can I correct a return I've already filed?

Yes. If you spot an error, you file a corrective tax return (if the filing deadline has not yet passed) or an additional tax return (after the deadline has passed). An additional return must be filed by the end of the month following the month in which you discovered the error.