Scale, flat tax or lump sum? Tax form comparison
The scale, the flat tax and the lump sum are taxed on different bases and carry different health contributions — which is why the cheapest one changes with your costs, your family and your rate. Change the numbers and watch the ranking move.
The lump sum ignores these for tax — but you still pay them.
Fixed by your activity, not by choice.
Child relief applies on the scale only.
- Taxable base—
- Income tax—
- Social contributions—
- Health contribution—
- Effective burden—
- Taxable base—
- Income tax—
- Social contributions—
- Health contribution—
- Effective burden—
- Taxable base—
- Income tax—
- Social contributions—
- Health contribution—
- Effective burden—
—
a year against the next-best form
Where the flat tax overtakes the scale
—
The deadline that decides it
You choose once a year, by the 20th of the month after your first revenue — 20 February for most businesses. Miss it and last year’s form carries over.
An estimate on 2026 rates. It assumes a full year of trading, one source of business income, no loss carried forward and no reliefs beyond those selected. Not tax advice.
Is that figure right for your case?
Send it to us and we will check it against your actual position — no charge for the first conversation.
Rates used (2026) — verified
- Zakład Ubezpieczeń Społecznych Składki przedsiębiorców w 2026 roku — Analiza Wydziału Planowania Funduszy, luty 2026 zus.pl
- Ministerstwo Finansów Ustawa o podatku dochodowym od osób fizycznych — scale, flat tax and lump-sum rates podatki.gov.pl
Figures are official rates for the tax year shown. They are not advice on your own case.
01 When can I change my tax form?
Once a year, by the 20th day of the month following the month in which you earn your first revenue of that year — in practice 20 February for most businesses. The declaration goes through CEIDG or straight to the tax office, and it binds you for the whole year, so it is worth running the numbers in January rather than in December.
02 Why does the lump sum sometimes win even at a higher rate?
Because the health contribution behaves completely differently. On the scale it is 9% of your income with no ceiling, and on the flat tax 4,9%; on the lump sum it is one of three fixed amounts keyed to revenue, so a profitable business with few costs can pay a few hundred złoty a month where the scale would take thousands. The trade-off is that the lump sum ignores your costs entirely — the moment your costs are large, it loses badly.
03 What do I give up by leaving the tax scale?
The 30 000 zł tax-free amount, joint assessment with a spouse and the child relief — none of which exist on the flat tax or the lump sum for business income. For a single earner with a non-working spouse and two children, those three together are often worth more than the headline rate difference, which is exactly why this calculator asks about them.
- Sole trader or sp. z o.o.? Tax comparison Put a sole proprietorship on the scale, the flat tax and the lump sum next to a limited company on classic and Estonian CIT — same revenue, five bottom lines, 2026 rates.
- Salary calculator — gross to net Estimate take-home pay in Poland across employment, mandate, specific-task and B2B contracts — with a full breakdown of ZUS, health and tax.
- Employer cost calculator — what a hire really costs Gross pay is not the cost. See the full ladder from what leaves your account to what lands in the employee’s — pension, disability, accident, Labour Fund, FGŚP and PPK, at 2026 rates.
- Company formation cost in Poland Every fee, itemised: court fee, transfer tax, notarial tariff, sworn translation and a qualified signature — with the online S24 route priced against a notarial deed and against a sole proprietorship.
Tell us about your business. We’ll map the next steps.
Leave your details and we’ll come back within one business day — with concrete answers, not a sales pitch.
- Free 30-minute introductory call
- English, Polish, Turkish, Russian, Ukrainian, Arabic and Romanian support
- No obligation — clear next steps