Poland B2B Calculator

B2B (jednoosobowa działalność gospodarcza) means you register as a sole proprietor and invoice a client company instead of being a payroll employee. It's the dominant arrangement in Polish IT because it's tax-advantageous: contractors choose their own taxation mode, pay a fixed ZUS social-insurance amount rather than a percentage of pay, and can often net significantly more than an equivalent gross salary under standard employment (umowa o pracę).

Skala podatkowa (progressive scale) taxes income at 12% up to PLN 120,000/year and 32% above, with a PLN 30,000 tax-free amount, but allows real cost deductions. Podatek liniowy (flat tax) applies a flat 19% to business income with no tax-free amount. Ryczałt (lump-sum) applies a flat rate, 12% for most IT/software services, directly to gross revenue with no cost deductions at all. Each mode also calculates health insurance (NFZ) differently. At 18.000 PLN/month revenue, ryczałt nets about 13.364 PLN/month, liniowy about 12.381 PLN/month, and skala about 11.783 PLN/month.

It depends on revenue and costs. Ryczałt is often best for contractors with low deductible business costs, since 12% on gross revenue with a flat, capped NFZ contribution frequently beats the alternatives at typical IT contractor rates, a gap of roughly 1.581 PLN/month against skala in the worked example above. Podatek liniowy tends to win at higher revenue levels for contractors with few costs to deduct, since NFZ is a percentage-of-income (4.9%) rather than a flat ryczałt band once income climbs. Skala podatkowa is rarely optimal for B2B contracting specifically (it's really designed for standard employment), but it's included here for completeness and because it can suit contractors with substantial deductible costs. Use the calculator's mode comparison above to see which wins at your own rate.

ZUS (Zakład Ubezpieczeń Społecznych) is Poland's mandatory social insurance system, covering retirement, disability, and accident insurance. For an established sole proprietor on the standard "duży ZUS" rate, it's a fixed monthly PLN amount (not a percentage of your revenue), set annually as a percentage of the average national wage. This calculator uses the 2026 standard rate; it doesn't model the lower preferential rates available to brand-new businesses in their first 24 months.

NFZ (Narodowy Fundusz Zdrowia) is Poland's public health insurance contribution, mandatory for all B2B contractors. Since the 2022 Polski Ład reforms, how it's calculated depends on your taxation mode: under skala it's 9% of income, under liniowy it's 4.9% of income, and under ryczałt it's a flat monthly amount that steps up in bands as your annual revenue crosses PLN 60,000 and PLN 300,000. This mode-dependent difference is one of the most consequential and easy-to-miscalculate parts of Polish B2B taxation.

12% is the standard ryczałt rate for software development and programming services (usługi związane z oprogramowaniem), which covers most IT contractor work. A narrower 8.5% rate applies to some adjacent, non-development service categories under specific PKWiU classifications. This is a genuinely disputed classification area in current tax-authority guidance, so if your work sits outside general software development, confirm your exact rate with an accountant before relying on it.

Only partially. For skala and liniowy, this calculator uses revenue minus mandatory ZUS contributions as a simplified cost base, rather than modeling itemized business expenses (laptop depreciation, home-office costs, accounting fees, etc.), real contractors with meaningful costs will see a lower actual tax bill under skala/liniowy than shown here. Ryczałt allows no business-cost deductions by design, though the social ZUS you pay and half your health contribution do come off its revenue base, and the calculator includes both, so its figure doesn't depend on your actual expenses.