The flat tax (podatek liniowy) is a form of taxation of business activity in which all income is subject to a single 19% rate, regardless of its amount. Unlike the tax scale (12% and 32%), there is no tax-free amount or income threshold, and unlike ryczałt (lump-sum tax on recorded revenue) its base is income — the difference between revenue and the costs of earning it. Below we discuss the rules, the profitability calculation and the procedure for changing the form of taxation in 2026.
Who the flat tax is intended for
Only entrepreneurs running a sole proprietorship (JDG) and partners in personal partnerships settling PIT can use this form. The PIT Act (Article 30c) introduces one important restriction: in the year in which the entrepreneur has chosen this form, they may not provide services corresponding to activities which, under an employment relationship, they have performed in the same year for their current or former employer. A breach of this rule results in loss of the right to the flat tax from the first day of its application — the entrepreneur must return to the scale and pay the outstanding advances.
How the tax is calculated
The calculation procedure is similar to the scale, but without brackets:
- Total revenue cumulatively from the beginning of the year.
- Deduction of the costs of earning the revenue recorded in the KPiR (tax book of revenue and expenditure).
- Deduction of paid social insurance contributions (social ZUS, excluding health).
- Deduction of the health contribution within the applicable annual limit (below).
- Multiplication of the result by 19%.
- Reduction by the sum of advances paid during the year.
The annual return is filed on the PIT-36L form by 30 April of the following year; in the settlement for 2025, the deadline falls on 30 April 2026.
Health contribution and deduction limit
On the flat tax, the health contribution is 4.9% of income — but no less than 9% of the minimum wage (minimum monthly contribution). The annual limit for deducting the paid health contribution from income (or treating it as a cost) is PLN 12,900 in 2025 and PLN 14,100 in 2026. This solution partly eases the flat-tax health contribution burden, but does not restore the full deduction that existed before the 2022 changes.
What cannot be deducted or applied
Compared to the tax scale, the flat tax takes away several important instruments:
- no tax-free amount (on the scale — PLN 30,000),
- no joint settlement with a spouse and no preference for single parents,
- no child relief settled from income subject to the flat tax (the relief applies only to income taxed under the scale — if the entrepreneur also has scale income, they can use the relief there),
- no internet relief,
- no youth relief (people under 26 benefit from it only on the scale and under specified civil-law contracts).
What is retained, however, includes the IKZE relief, rehabilitation relief, thermomodernisation relief, research and development relief, and the so-called IP Box relief (taxation of qualified income from intellectual property at a 5% rate). The flat tax can therefore be combined with IP Box in the annual return, which is particularly relevant for developers and R&D specialists.
When the flat tax pays off — the break-even point
The point at which the flat tax overtakes the tax scale depends on family situation, reliefs, costs and the amount of the health contribution. As a reference point in 2026:
- an entrepreneur without reliefs and without joint settlement starts to gain from the flat tax at roughly PLN 115,000–130,000 of annual income — below that, the scale wins thanks to the tax-free amount and the 12% rate,
- an entrepreneur settling jointly with a low-earning spouse — the break-even point moves clearly upwards (into the hundreds of thousands of zloty),
- a high-earning entrepreneur (above PLN 400,000) almost always gains from the flat tax, because the scale's 32% rate is much higher than 19%.
In each case, it is worth preparing a calculation for the specific business — a projection of revenue, costs, contributions and reliefs gives a result closest to reality.
Comparison with ryczałt
Ryczałt taxes revenue (without costs) at industry-specific rates — in IT most often 8.5% or 12%. It pays off where the costs of earning income are low (e.g. B2B contracts of IT specialists, consulting services). Where costs are high (trade, manufacturing, employing a team), the flat tax has the edge, because it allows income to be reduced by actual expenses. An additional factor is the health contribution: on ryczałt there are three fixed brackets, on the flat tax it is 4.9% of income with a deduction limit.
How to choose the flat tax
The choice is made:
- when registering the activity in CEIDG — in the "form of taxation" field of the CEIDG-1 application,
- during the course of running the business — by changing the CEIDG entry by the 20th day of the month following the one in which the first revenue of the year appeared (most often by 20 February),
- optionally, by a statement filed directly with the head of the tax office (CEIDG forwards it to the tax office automatically).
The choice applies to the whole year. Changing the form during the year is not possible — a subsequent change takes effect only from January of the following year.
Recording duties and deadlines
- keeping the Tax Book of Revenue and Expenditure (KPiR) (or accounting books after exceeding the limit of EUR 2 million of revenue),
- payment of monthly or quarterly tax advances by the 20th day of the month following the settlement period (quarterly advances available for small taxpayers and those starting activity),
- annual PIT-36L return by 30 April of the following year,
- settlement of the health contribution in the annual ZUS return (annual DRA) — filed by 20 May of the following year.
When the flat tax does not pay off
It is worth rejecting the flat tax if:
- the company's income is low and does not exceed a few dozen thousand zloty a year — the scale with its PLN 30,000 tax-free amount gives effectively lower burdens,
- you plan to settle jointly with a low-earning spouse,
- you want to use the child relief for several children without other sources of income,
- you worked in the same year for your current counterparty under an employment relationship — the restriction in Article 30c of the PIT Act may wipe out the benefit.
How Good Balance can help
We prepare an individual calculation of the choice of form of taxation, file the choice of the flat tax in CEIDG, keep the KPiR and handle monthly advances. We combine the flat tax with IP Box, prepare records of qualified income and support clients in verifications by the tax office. See our offer: sole proprietorship services, simplified accounting and help with tax rulings. Related articles: general rules (tax scale) and ryczałt on recorded revenue.