The form of taxation of a sole proprietorship is changed once a year, in advance: the statement must be filed by the 20th day of the month following the one in which the first revenue of the year appeared (if the first revenue is in December, the deadline is 31 December). The easiest way is to file an application to amend the entry in CEIDG (Central Register and Information on Economic Activity). Missing the deadline means the previous form applies for the whole year, and for a new business – the tax scale.
How the deadline works – and why it is not always 20 February
The regulations do not set a fixed date. The deadline runs from the first revenue of the year, so for different entrepreneurs it falls in different months:
| First revenue in 2027 | Last day to change the form |
|---|---|
| in January (e.g. an invoice from 4 January) | 20 February 2027 |
| in March (January and February without sales) | 20 April 2027 |
| in December | 31 December 2027 |
A trap to watch for: revenue is the amount due, not the inflow to the account. An invoice issued on 2 January for a service rendered in January "triggers" the deadline even if the client pays in March. When the 20th day of the month falls on a non-working day, the deadline moves to the next working day.
The change applies from the start of the tax year – you cannot switch to another form mid-year just because the results turned out different from what was assumed. A filed statement also works in the following years, until the entrepreneur files a new one.
What changes are possible
- from the scale to flat tax (podatek liniowy) or ryczałt (lump-sum tax on recorded revenue) – a statement choosing the new form,
- from flat tax or ryczałt back to the scale – a statement changing the current form (the scale is the default form),
- between ryczałt and flat tax in either direction – a statement choosing the new form within the same deadline,
- giving up the tax card – by 20 January; returning to the card is no longer possible, as since 2022 it may only be applied by people who used it earlier and did not drop it.
Ryczałt is not available to everyone – excluded are, among other things, certain types of activity and services provided to a current or former employer within the scope of previous duties. When choosing ryczałt, the correct rate for each type of revenue must also be identified – we describe this in the article on ryczałt and its rates.
How to file the statement step by step
- Log in to the entrepreneur's account on biznes.gov.pl (trusted profile, e-dowód (e-ID) or qualified signature).
- Choose the application to amend the data in the CEIDG entry.
- In the section on the form of income tax payment, mark the new form: general rules, flat tax or ryczałt.
- Sign and send the application, then keep the official confirmation of receipt – it is proof that the statement was filed on time.
- Inform the accounting office so that it changes the way advance payments and records are kept from January.
The statement can also be filed directly at the tax office. Partners in a civil-law partnership each file it in their own name, and ryczałt can be applied only if all partners file the statement.
What to recalculate before the change
The decision is best taken in the last quarter of the year, based on a forecast of revenue and costs for the following year. In 2026 the key parameters are:
| Form | Tax | Health contribution |
|---|---|---|
| Scale | 12% up to PLN 120,000 of income, 32% above, tax-free amount PLN 30,000 | 9% of income, min. PLN 432.54 per month |
| Flat tax | 19% of income regardless of amount | 4.9% of income, min. PLN 432.54 per month |
| Ryczałt | from 2% to 17% of revenue, depending on the type of activity | a fixed amount depending on the revenue bracket: PLN 498.35, PLN 830.58 or PLN 1,495.04 per month |
Beyond the rates themselves, it is worth taking into account:
- costs – ryczałt does not allow deduction of expenses, so with high costs (equipment, subcontractors, car) it usually loses to flat tax or the scale,
- losses – can arise only on the scale or flat tax; ryczałt is therefore worse in a year of large investments,
- joint settlement with a spouse and reliefs – available only on the scale; flat tax removes most reliefs, including the child relief,
- records – scale and flat tax require the KPiR (tax book of revenue and expenditure), ryczałt – revenue records; when switching, one must be closed and the other opened from January.
Example (2026, full social contributions): a developer earns PLN 200,000 of revenue with PLN 10,000 of costs. On the scale, after deducting costs and social contributions, income is about PLN 167,000 – tax is about PLN 25,800, and the health contribution (9%) is about PLN 15,000, together about PLN 40,800. On ryczałt at 12% tax will be about PLN 20,600 and the health contribution (bracket PLN 60,000–300,000) about PLN 10,000, together about PLN 30,600. If in the next year, however, they plan to buy equipment for PLN 60,000, the advantage of ryczałt would clearly shrink. That is why the choice is worth reviewing every year, not set once for ever. The scale and flat tax are also compared in our article on the flat tax.
The most common mistakes
- counting the deadline from the date money comes in rather than from the date of the revenue,
- assuming the change will "take effect" from the next month, not from the start of the year,
- choosing ryczałt without checking whether the activity can use it and at what rate,
- leaving the health contribution out of the comparison – on flat tax and the scale it rises with income.
How Good Balance can help
Before the end of the year we prepare a comparison of the forms of taxation based on real company data and the forecast for the following year, then file the statement in CEIDG within the deadline. Support with registration and amendments to the entry is provided under the business activity service, and the new records and advance payments are handled under simplified accounting.