From a B2B invoice of PLN 20,000 net per month, an entrepreneur on full ZUS keeps in 2026 — after contributions, tax and minor costs — between about PLN 12,400 and PLN 14,100, depending on the form of taxation. The difference between the variants grows with the rate, and the stage of ZUS contributions (start-up relief, preferential contributions, full ZUS) changes it even more strongly. Below are step-by-step calculations that let you estimate your own take-home amount.
What the "take-home" amount on a B2B contract consists of
The invoice amount (net of VAT) is only the starting point. VAT is not the contractor's income — it goes to the tax office in the JPK_V7 settlement, so we omit it in the calculations. Four items are deducted from net revenue:
- social contributions — retirement, disability, accident, voluntary sickness insurance plus the Labour Fund and the Solidarity Fund; in 2026, on full ZUS and the minimum base of PLN 5,652, this is a total of PLN 1,926.76 per month,
- health contribution — its amount depends on the form of taxation and on income or revenue,
- income tax — on the scale, flat tax (podatek liniowy) 19% or ryczałt,
- costs of running the business — accounting, equipment, software, phone.
A comparison of a B2B contract itself with employment at the same company budget is covered separately in the article B2B or employment contract. Here we focus solely on how the form of tax and the ZUS stage change the result of the contract itself.
Assumptions used in the calculations
- Year 2026, the contractor provides programming services for which the ryczałt rate is 12%.
- Business costs: PLN 1,000 net per month (under ryczałt they do not reduce the tax, but they still reduce the cash in pocket).
- Full ZUS with voluntary sickness insurance: PLN 1,926.76 per month, deductible from income or revenue.
- Scale: 12% up to PLN 120,000 of the base, 32% on the excess, tax-reducing amount PLN 3,600; health contribution 9% of income.
- Flat tax: 19%; health contribution 4.9% of income, deductible from income up to the limit of PLN 14,100 in 2026.
- Ryczałt: health contribution in a fixed amount depending on the revenue bracket (PLN 498.35, PLN 830.58 or PLN 1,495.04 per month); 50% of the paid contribution reduces revenue for taxation.
- Minimum health contribution on the scale and flat tax: PLN 432.54 per month. For simplicity, 2026 rates have been assumed for the full 12 months and reliefs settled in the annual return have been omitted.
Three rate levels, three forms of tax
The amounts are the average monthly net take-home after the annual settlement, rounded to the nearest zloty.
| Net invoice per month | Scale 12%/32% | Flat tax 19% | Ryczałt 12% |
|---|---|---|---|
| PLN 12,000 | PLN 7,468 | PLN 6,989 | PLN 7,084 |
| PLN 20,000 | PLN 12,373 | PLN 13,152 | PLN 14,124 |
| PLN 30,000 | PLN 18,273 | PLN 20,826 | PLN 22,299 |
What the table shows:
- At PLN 12,000 the scale turns out most favourable. The annual base (about PLN 108,900) falls within the 12% bracket, and the tax-reducing amount works in full. Ryczałt performs worse because the 12% tax is calculated on the whole revenue and business costs do not reduce it; the flat tax, in turn, offers no tax-free amount and takes 19% from the first zloty.
- At PLN 20,000 the scale loses out — part of the income falls into the 32% bracket, and a 9% health contribution on income already costs over PLN 18,000 per year. The 12% ryczałt beats the flat tax by almost PLN 1,000 per month.
- At PLN 30,000 ryczałt's advantage remains, even though revenue exceeds the PLN 300,000 threshold and the health contribution rises to PLN 1,495.04 per month.
How the PLN 20,000 row was calculated — step by step
- Annual revenue: PLN 240,000. Costs: PLN 12,000. Social contributions: PLN 23,121.
- Ryczałt: base = 240,000 − 23,121 − 50% of PLN 9,967 health contribution ≈ PLN 211,895; tax 12% ≈ PLN 25,427. Take-home: 240,000 − 12,000 − 23,121 − 9,967 − 25,427 ≈ PLN 169,485, i.e. about PLN 14,124 per month.
- Flat tax: income = 240,000 − 12,000 − 23,121 = PLN 204,879; health contribution 4.9% ≈ PLN 10,039; base after deducting the contribution (within the PLN 14,100 limit) ≈ PLN 194,840; tax ≈ PLN 37,020. Take-home about PLN 13,152 per month.
- Scale: the same income PLN 204,879; health contribution 9% ≈ PLN 18,439 (no deduction); tax = 10,800 + 32% × 84,879 ≈ PLN 37,961. Take-home about PLN 12,373 per month.
The ZUS stage changes the result more than the form of tax
A new business usually goes through three stages: 6 months of start-up relief (no social contributions, only the health contribution is paid), then up to 24 calendar months of contributions on the preferential base (PLN 1,441.80 in 2026), and then full ZUS. Below is the same contract at PLN 15,000 net per month, calculated as if a given stage lasted the whole year.
| Contribution stage (2026) | Social contributions per month | Ryczałt 12% | Flat tax 19% |
|---|---|---|---|
| Start-up relief | PLN 0 | PLN 11,419 | PLN 10,784 |
| Preferential contributions | PLN 456.18 | PLN 11,018 | PLN 10,433 |
| Full ZUS | PLN 1,926.76 | PLN 9,724 | PLN 9,300 |
Moving from start-up relief to full ZUS reduces the take-home amount by almost PLN 1,700 per month — more than the difference between ryczałt and the flat tax at this rate. It is worth bearing this in mind when the first months of the business are used to judge whether B2B "is worth it". The conditions of start-up relief are described in the article on ZUS contributions in Poland.
Lower contributions have another side: a lower base for future retirement and a lower sickness benefit (there is no sickness insurance at all under start-up relief).
Ryczałt rate of 8.5% instead of 12%
Some B2B contracts in IT do not concern creating software but, for example, consulting or technical support services, for which the 8.5% rate may be appropriate. For a PLN 15,000 net invoice and full ZUS the difference is about PLN 440 per month (about PLN 10,167 instead of PLN 9,724 take-home). The rate, however, is determined by the actual type of service according to the PKWiU classification, not by the invoice description — the rules are discussed in the article on the 12% and 8.5% rates for IT specialists.
What the tables do not show
- Costs above PLN 1,000 per month (car lease, more expensive equipment) improve the result on the scale and flat tax, but not on ryczałt.
- Reliefs in the annual return — child relief and joint settlement with a spouse are available on the scale, but not on the flat tax or ryczałt.
- Gaps in assignments — ZUS contributions are also paid in months without an invoice, which at low rates hits the result hard.
- Holiday and sickness — on B2B no one pays for days off; with 20 days off in a year, the real monthly income drops by several percent.
- Changing the form of taxation is in principle possible once a year, by the 20th of the month following the month of first revenue in the given year, so the decision is worth taking on the basis of a forecast for the whole year.
How Good Balance can help
We prepare an individual simulation for a specific rate, costs and ZUS stage, and in case of doubt about the ryczałt rate we help obtain an individual tax interpretation. We also run ongoing settlements for sole proprietorships as part of simplified accounting.