Changing the form of taxation in 2026: the 20 February deadline and exceptions

The choice of form of taxation for a sole trader business and a partnership is a decision that binds you for the whole tax year. Article 9a of the PIT Act sets a strict rule: by 20 February of the given year you must file a declaration on the choice of form if you want to change it from the default tax scale to the flat tax or lump-sum tax (or between them). More precisely: the declaration is filed by the 20th day of the month following the month in which the first revenue of the year was earned. With revenue in January, that is 20 February (Article 9a(2) of the PIT Act, Article 9(1) of the Act on lump-sum income tax). After that deadline you are bound until the end of December.

In 2026 the rules have not changed compared with 2025, but the choice itself matters more than ever because of the reform of the health insurance contribution (from 2022) and the introduction of new reliefs (R&D, IP Box, Estonian CIT for companies).

Forms available in 2026

For sole trader businesses and partners in partnerships, three forms remain active:

| Form | Rate | Health insurance contribution | Costs deducted | |-------|--------|---------------------|--------------------| | Tax scale | 12% / 32% (threshold PLN 120 thousand) | 9% of income (minimum PLN 432.54 a month) | Yes | | Flat tax | 19% | 4.9% of income (minimum PLN 432.54 a month; deduction up to PLN 14,100 a year) | Yes | | Registered lump-sum tax | 2%–17% (depending on the type of service) | Fixed amounts (PLN 498.35 / 830.58 / 1,495.04) | No (from revenue) |

The tax card is theoretically active, but reserved for people who used it before 2021 and continue it without a break.

A full comparison of the forms is in our article PIT 2026 for entrepreneurs: tax-reducing amount, thresholds, lump-sum tax.

How to change the form: the procedure

For a sole trader business

1. Go to biznes.gov.pl
2. File the change in the Central Register and Information on Business (CEIDG): form CEIDG-1, the section “Choice of form of taxation”
3. Tick the new form: scale, flat tax or lump-sum tax (for lump-sum tax choose the specific industry rate)
4. Sign electronically: with a Trusted Profile or an e-ID card
5. Confirmation: you will receive it within 1 day, and the change takes effect from 1 January

For a partner in a partnership

The declaration is filed by each partner separately. A partnership is tax-transparent, and the partners are taxed individually.

Partners in a general partnership and a professional partnership file a written declaration with the head of the tax office. Partners in a civil-law partnership can do it through CEIDG.

A limited partnership has been a CIT taxpayer since 2021, so its partners do not choose a PIT form of taxation in the way described here.

For a limited company (sp. z o.o.) (CIT)

A limited company does not choose a PIT form. It is taxed under CIT. It can, however, choose Estonian CIT (details in the article Estonian CIT 2026). The declaration is filed on form ZAW-RD by the end of the first month of the tax year (for companies with a calendar year, by 31 January).

The 20 February deadline

You file the declaration on the change of form by 20 February of the tax year.

A preclusive deadline: filing on 21 February no longer works. What decides is the date of receipt by CEIDG or the tax office, not the date of posting. That is why you should file electronically, ideally by 19 February.

Exceptions: when you can change during the year

Exception 1: closing a business and starting a new one

Closing a business and setting up a new one is not a statutory exception to the deadline for changing the form of taxation, and it can be misleading. If the new business is in essence a continuation of the previous one, the tax office may treat such a step as circumventing the rules.

An example of circumvention: you close one IT sole trader business and open a second IT sole trader business.

Exception 2: a new business during the year

If you start a business during the year, you choose the form of taxation when registering in CEIDG, and you file the declaration on the flat tax or lump-sum tax by the 20th day of the month following the month in which you earn your first revenue at the latest (Article 9a(2) of the PIT Act, Article 9(1) of the Act on lump-sum tax).

Exception 3: a forced change from lump-sum tax

If revenue under lump-sum tax exceeds EUR 2,000,000 a year (the limit for registered lump-sum tax), a compulsory change to the scale or the flat tax follows from the next year. There is no need to file a declaration: the change happens by operation of law.

Exception 4: a change in the structure of the company

When a partnership is converted into a capital company (for example general partnership → limited company), there is an automatic change from PIT to CIT. The details depend on the form of the conversion.

Calculating profitability: how to think about it

Before changing the form we recommend a comparative calculation based on last year’s numbers:

1. Estimate income or revenue for 2026 (most often assuming +5–10% compared with 2025)
2. Calculate the PIT for each form
3. Add the health insurance contribution according to the formula for each form
4. Take reliefs into account: spouse, children, family reliefs (the scale only), IP Box, R&D
5. Compare the total effect

The most common traps

1. Lump-sum tax without checking the classification of the service: different types of service have different rates, and they are assigned to the PKWiU classification, not to the PKD code entered in CEIDG. Programming services are settled at 12%, and other advisory services may have a higher rate (for example 15%). A difference of 3 percentage points × revenue = significant amounts.
2. The scale at high incomes: an income of PLN 250 thousand on the scale = 32% on the excess of PLN 120 thousand + a 9% contribution = about 38% in total. The flat tax would give 19% + 4.9% = about 23%.
3. The flat tax without family reliefs: the flat tax rules out joint taxation with a spouse and the child relief. For a family with 2 children that is 2 × PLN 1,112 = PLN 2,224 a year of lost relief.
4. A change during the year without a basis: the risk of being challenged by the tax office, penalty interest.

Summary

Changing the form of taxation is an annual decision, with a deadline of 20 February. Not filing a declaration means staying with the current form. A comparative calculation should be standard every January. At Profais we prepare an analysis of the profitability of the forms of taxation within two working days for every client. See our revenue and expense ledger (KPiR) service. We are an accounting firm, not a tax adviser. We explain how the rules translate into your accounts, and tax advice and opinions that go beyond day-to-day accounting are provided by tax advisers (in line with the Tax Advisory Act). More about the health insurance contribution that affects this decision is in Health insurance contribution 2026.

Sources: biznes.gov.pl: changing the form of taxation, the PIT Act (Articles 9a, 9b), the Act on lump-sum income tax (Article 9).