The deadline for changing your taxation form falls on 20 February. Find out how to choose between the tax scale, flat-rate income tax and lump-sum tax, and what formalities are required.
Every entrepreneur has the right to change the taxation form of their business activity once a year — but only within a strictly defined deadline. In 2026, as in previous years, the final date is 20 February. Missing this deadline means you will be settled on your current terms for the entire year, even if they are not beneficial to you. In this article we explain what taxation forms are available, how to compare them in terms of fiscal burden, and how to correctly submit your declaration to the tax office (US).
Polish tax law provides for several basic forms of taxation of business activity: • Tax scale (general rules) — rates of 12% and 32%, possibility of joint settlement with a spouse, full tax-free allowance and the right to most tax reliefs. • Flat-rate income tax (podatek liniowy) — uniform rate of 19%, no right to joint settlement or most tax reliefs, but advantageous at higher income levels. • Lump-sum tax on recorded revenues (ryczałt od przychodów ewidencjonowanych) — rates from 2% to 17% depending on the type of activity, tax calculated on revenue (without costs). • Tax card (karta podatkowa) — available only to taxpayers who were using it before 2022. The choice should take into account not only the rate itself, but also the health insurance contribution (składka zdrowotna), which from 2026 continues to differ depending on the chosen form.
The decision on the form of taxation should be based on several key variables: 1. Projected income or revenue during the year — at low income levels the tax scale with the tax-free allowance is often the cheapest option; at high levels, flat-rate income tax is preferable. 2. Level of tax-deductible costs — the lump-sum tax does not take costs into account, so it is advantageous for businesses with low operating expenses. 3. Type of activity carried out — not every activity qualifies for the lump-sum tax or preferential rates. 4. Entitlement to reliefs — the tax scale allows, among others, the child relief, R&D relief or IP Box, while flat-rate income tax permits only selected deductions. 5. Amount of the health insurance contribution — its calculation differs depending on the form, which has a real impact on the total burden. It is worth preparing a simulation using real figures from the previous year before submitting your declaration.
Under the provisions of the Personal Income Tax Act, the declaration on the change of taxation form is submitted by the 20th day of the month following the month in which you received your first revenue in a given tax year. In practice, for the vast majority of entrepreneurs who received revenue as early as January, this deadline falls on 20 February. Missing the deadline is effective only in exceptional situations defined by law — for example, when registering a new business during the year. For existing businesses, a late submission means automatically remaining on the current form for the entire year. There is no possibility of filing a correction or an application for reinstatement of the deadline in this regard. It is therefore best to make the decision as early as December or at the beginning of January.
The declaration on the choice of taxation form is submitted to the head of the tax office (naczelnik urzędu skarbowego) competent for the taxpayer's place of residence. In practice, you can do this in several ways: • Via the CEIDG-1 form (entry update) — the change simultaneously constitutes a declaration to the tax office. This is the most convenient and most commonly used method. • A written declaration submitted directly to the tax office — possible if for some reason you are not updating CEIDG. • Electronically via the biznes.gov.pl portal or ePUAP. Please note that changing from the lump-sum tax to general rules or flat-rate income tax and vice versa requires an explicit indication of the new form — remaining on the previous form by default does not require any action. It is recommended to retain confirmation of the submission of the declaration in the event of any disputes with the tax authority.
The health insurance contribution (składka zdrowotna) remains one of the most important factors affecting the total burden on an entrepreneur. In 2026, the rules for its calculation are as follows: • Tax scale — the contribution amounts to 9% of income, with no possibility of deduction from tax. • Flat-rate income tax — the contribution amounts to 4.9% of income (not less than the minimum base), with the possibility of partial deduction from income or inclusion in costs. • Lump-sum tax — the contribution is set on a flat-rate basis across three thresholds depending on the level of revenue. This means that income tax itself is only part of the calculation. A full analysis should account for the total burden: tax + health insurance contribution + ZUS contributions where applicable. For many entrepreneurs, changing the taxation form brings savings precisely at the level of the health insurance contribution rather than the tax itself.
Practitioners from accounting firms observe several recurring mistakes: • Missing the deadline — the most common problem, resulting from postponing the decision until the last moment. • Failure to analyse costs — choosing the lump-sum tax for businesses with high operating costs can drastically increase the burden. • Ignoring the health insurance contribution — calculating only income tax without the contribution gives a false picture of the savings. • Incorrect CEIDG update — entering the wrong code for the taxation form or failing to record the change. • Changing without consulting a specialist — with ambiguous revenue streams (e.g. mixed activity), the regulations can be non-obvious. It is worth bearing in mind that changing the taxation form is a decision for the entire year — any correction is only possible from the following tax year.
Changing the taxation form is one of the most important financial decisions an entrepreneur can make for a given year. It requires an analysis of income, costs, the health insurance contribution and available tax reliefs — all within a very short window of time before 20 February. If you want to make this decision on the basis of reliable calculations rather than intuition, we invite you to contact Danexis accounting firm. Our specialists will help you choose the optimal form and complete all formalities on time. Call us on +48 780 760 666 or write to kontakt@danexis.pl.