Employment contract (UoP) — payslip-style model

The engine simulates a real monthly payslip, not a smoothed annualization. Employee pension (9.76%) and disability (1.5%) contributions use the annual base cap of PLN 282,600 (30 times the monthly forecast average wage for 2026 under the Polish Social Insurance Act—the usual “30×” pension/disability ceiling) enforced year-to-date: full contributions until YTD base + current month ≤ PLN 282,600; a top-up in the overflow month (typically December for PLN 25,000 gross); zero pension/disability afterwards. Sickness 2.45% has no cap. Each contribution is rounded to grosze separately and summed like on an actual payslip. Health 9% on the post-employee-ZUS base.

PIT advance: progressive 12%/32% with a PLN 120,000 annual bracket threshold, computed month by month with YTD tracking of the PIT base: (a) if YTD + current month ≤ 120k → month × 12%; (b) if YTD ≥ 120k → month × 32%; (c) in the crossover month the portion up to 120k is taxed at 12% and the rest at 32%. The monthly PIT-2 relief (0 / 100 / 150 / 300 PLN) is subtracted from the advance, then the result is rounded to a whole PLN. Youth relief (PIT-0 for <26) zeroes PIT for UoP/zlecenie when the annual PIT base is within the statutory limit.

Three net figures on the main result card: “January payout” = January net (YTD = 0, full ZUS, full relief, first PIT bracket); “Monthly average” = annual net / 12; “Lowest month” = the smallest monthly net (typically after crossing the 120k threshold). The 12-month projection matches wynagrodzenia.pl to the grosz for the reference case of PLN 25,000 gross UoP. This is still an educational model — a full yearly PIT return (spousal settlement, year-only reliefs, year-end reconciliation) requires payroll/accounting software.

Contract work (zlecenie)

When a zlecenie contract is a title to insurance, the contractor pays mandatory pension (9.76%) and disability (1.5%) contributions (annual cap applied YTD, same as UoP) plus health (9% on post-ZUS base). The sickness contribution 2.45% is VOLUNTARY (Art. 11 par. 2 of the Social Security Act) — we expose it as an optional checkbox, unchecked by default. Accident insurance (0.67–3.33%) is paid entirely by the contracting party (not the contractor). PIT is computed payslip-style month by month with cumulative base. KUP is 20% (or 0%) on the post-ZUS base — no UoP 250/300 PLN monthly allowance. Student contract (<26 with student status) skips ZUS and health; youth relief zeroes PIT. The youth relief in the model compares annual gross (× 12) to the 85,528 PLN limit — gross revenue, not the post-ZUS/KUP PIT base. The three net figures (January / average / minimum) are shown whenever contributions are on.

Contract for specific work (dzieło)

0 / 20 / 50% KUP on the appropriate base; by default no ZUS. “Work for own employer” forces the ZUS path and the engine switches to the payslip-style UoP model (YTD cap, monthly PIT with cumulative base, three net figures).

B2B / sole proprietorship

Linear 19%: health 4.9% on a base at least the minimum wage when taxable income is positive; with positive business revenue but non-positive income after costs and social, at least the monthly minimum health applies (January 314.96 PLN, from February 432.54 PLN). Part of health reduces taxable income with a simplified monthly slice of the 14 100 PLN annual cap. Health base from the previous month per ZUS rules is not implemented - we use the current month as a simplification.

Scale: same progressive PIT as employment on income after costs and social; health 9% with the same minimum rules as linear.

Lump-sum: tax on revenue at the selected rate; stepped health contributions from cumulative revenue (optional YTD input); optional deduction of 50% of health from revenue before the lump rate.

ZUS (JDG) simplifications

Variants: no contributions (e.g. start relief), preferential, full, small ZUS plus (~half of full basis), custom amount, contribution holiday (no social in that month). This does not replace individual ZUS calculations.

Net → gross

Binary search on gross → net with penny polish at the end. Monthly PIT advance is rounded to whole PLN (after grosze calculation). For a given net there may be a small gross “window”; we return the lowest gross that still meets the target—other tools may pick a higher point in that band (minor contribution differences).

Net → gross (B2B)

Row amounts are client totals including VAT, not target take-home net; the engine derives invoice net and allocates across sources.

Employer cost

By default we show gross + estimated employer ZUS (incl. FP/FGŚP) + employer PPK when you enter an employer PPK percentage—educational estimate only.