In Poland, a "B2B contract" usually means invoicing a client as your own business, typically a JDG (jednoosobowa działalność gospodarcza, sole proprietorship), instead of being their employee. It is common among IT professionals, consultants and other specialists, and it usually pays more on paper than an equivalent salary. But an invoice amount is not take-home pay. You deduct ZUS (social insurance) contributions, a health contribution, and income tax yourself before anything reaches your account. This guide breaks down what actually gets deducted, compares B2B to employment with real numbers, and flags the legal risk of a B2B contract that turns out to be disguised employment, based on the rules in force in 2026.
What comes out of a B2B invoice before it is yours
Unlike an employment contract, on B2B you handle your own contributions and tax advances. Your invoice amount gets reduced by, in order:
- VAT, if you are VAT-registered, is added to the invoice but passes straight through: it is not your income.
- ZUS social contributions (pension, disability, accident and, optionally, sickness insurance).
- The health contribution, which varies depending on your tax form.
- The income tax advance, under skala, liniowy or ryczałt.
- Deductible business costs, if you have any to claim.
What is left after all of that is your real net income. Two decisions affect it more than anything else: your tax form, and your ZUS variant.
How much is ZUS on a B2B contract in 2026
| ZUS variant | Social contributions | With the health contribution (min.) |
|---|---|---|
| Ulga na start (start relief), 6 months | 0 PLN | 432.54 PLN |
| Preferential contributions, 24 months | 456.18 PLN | 888.72 PLN |
| Full ZUS | 1,926.76 PLN | 2,359.30 PLN |
New businesses can cut their costs substantially for their first two and a half years: six months on the health contribution alone, then twenty-four months on a preferential base, before full ZUS applies.
The health contribution itself depends on your tax form: 9% of income (minimum 432.54 PLN) on skala, 4.9% of income (minimum 432.54 PLN, deductible up to 14,100 PLN a year) on liniowy, or a fixed amount by revenue bracket on ryczałt: 498.35 PLN, 830.58 PLN or 1,495.04 PLN a month.
A timing note. The 432.54 PLN minimum applies from February 2026 through January 2027. The health contribution has its own coverage year, running February to January rather than the calendar year, so January 2026 still fell under the previous year's, lower, minimum. The figures in this guide use the February 2026 minimum, which is current for most of the year.
What is actually left: example take-home figures
The table below shows approximate monthly net income at full ZUS, for a few invoice amounts and tax forms, assuming low business costs:
| Invoice/month | Ryczałt 12% | Liniowy 19% | Skala 12% |
|---|---|---|---|
| 5,000 PLN | ~3,100 PLN | ~2,950 PLN | ~3,050 PLN |
| 10,000 PLN | ~7,100 PLN | ~6,700 PLN | ~6,900 PLN |
| 15,000 PLN | ~10,800 PLN | ~9,949 PLN | ~9,800 PLN |
| 20,000 PLN | ~14,400 PLN | ~13,100 PLN | ~12,400 PLN |
These are approximate and assume low costs. Your own numbers will shift with real business expenses and any reliefs you qualify for.
A worked example. An IT freelancer invoicing 15,000 PLN a month, on full ZUS and ryczałt 12%: ZUS social contributions of 1,926.76 PLN, a health contribution of 830.58 PLN (the second revenue bracket), and ryczałt tax of roughly 1,700 PLN after deducting 50% of the health contribution from revenue, leaving roughly 10,500-10,800 PLN net. The same freelancer on liniowy 19%, with low costs, nets roughly 9,949 PLN instead, which shows why ryczałt tends to win for IT contractors with few deductible costs.
Which tax form leaves you the most
- Ryczałt (12% for IT, 8.5% for many other services) usually wins at low business costs.
- Liniowy, at a flat 19%, usually wins at high costs, since you can deduct them, or at income above roughly 120,000 PLN a year.
- Skala (12%/32%) wins at lower income, thanks to the 30,000 PLN tax-free amount, and if you also have other income taxed under general rules, such as a salary.
Because ZUS is a flat amount rather than a percentage of revenue, its share of your income shrinks as you earn more. At higher invoice amounts, your effective rate moves closer to your headline tax rate, which is why high-earning contractors on ryczałt often end up with some of the lowest effective rates overall.
B2B vs. employment: a real comparison
At the same cost to the paying company, B2B typically nets 20-40% more than an equivalent salary. Here is why, using a company willing to spend 12,293 PLN a month either way:
As an employment contract, paying a 10,000 PLN gross salary: employer ZUS contributions (about 20.48%) add 2,048 PLN, the Labor Fund (2.45%) adds another 245 PLN, and the employer's total cost comes to 12,293 PLN. The employee takes home roughly 7,095 PLN net.
As a B2B invoice for that same 12,293 PLN, on liniowy 19%: minus ZUS (1,927 PLN), minus the health contribution at 4.9% (roughly 506 PLN), minus 19% tax (roughly 1,873 PLN), leaves roughly 7,987 PLN net, about 892 PLN more than the employee.
On ryczałt 12% (a common rate for programmers): minus ZUS (1,927 PLN), minus the health contribution (first bracket, 498 PLN), minus ryczałt tax (roughly 1,475 PLN), leaves roughly 8,409 PLN net, about 1,314 PLN more than the employee, over 15,000 PLN a year.
What you give up moving to B2B
| Employee benefit | Estimated value/year |
|---|---|
| Paid annual leave (26 days) | 5,000-15,000 PLN |
| Sick pay | Varies |
| Maternity/parental leave | Varies |
| Equipment, phone, software | 2,000-5,000 PLN |
| Employer-funded training | 1,000-5,000 PLN |
| Job security | Hard to price |
On B2B, there is no paid leave. A day off is a day without income. Sick pay only exists if you pay a voluntary sickness contribution (2.45% of your ZUS base, roughly 138 PLN a month at full ZUS), and even then it only starts from day 34 of a continuous absence, and only once you have been insured for at least 90 days. On an employment contract, sick pay starts from day one.
When B2B is worth it, roughly
| Monthly net rate | Is B2B worth it? |
|---|---|
| Up to 6,000 PLN | Usually not, ZUS and your own costs eat the difference |
| 7,000-9,000 PLN | Depends on your industry and costs, worth calculating |
| Above 10,000 PLN | Usually yes, the benefit is clear |
At lower ZUS costs, such as during the start relief or on Mały ZUS Plus, the break-even point is lower too.
Fake B2B: a real legal risk
A B2B contract is only legal if you genuinely run an independent business. ZUS and tax authorities can examine whether a B2B relationship is actually employment in disguise, and reclassify it if so. Under Poland's Labor Code (art. 22), signs of a real employment relationship include: working at a place and time set by the client, working under the client's direction and instructions, having a single client who supplies your tools and equipment, and carrying no economic risk yourself.
If ZUS or the Labor Inspectorate (PIP) finds a B2B contract to be disguised employment, the paying company can be ordered to pay the missing ZUS contributions for the entire period, with interest, and the contractor may have to return part of the tax benefit received. Safer B2B looks like having multiple clients, or the realistic ability to take on more, your own equipment, flexibility on time and place, and genuine economic risk.
Two 2026 changes worth knowing
Kasowy PIT (cash-basis PIT) has been available to JDG owners since January 1, 2025, when the revenue limit to qualify was 1,000,000 PLN a year. From January 1, 2026, that limit rose to 2,000,000 PLN a year (based on the prior year's revenue), so it now covers considerably more businesses. It lets you pay income tax only once the client has actually paid you, rather than at the moment you issue the invoice, which helps considerably if you deal with long payment terms.
KSeF, Poland's mandatory e-invoicing system, became compulsory for most businesses on April 1, 2026 (micro-businesses invoicing under 10,000 PLN a month have until January 1, 2027). If you invoice as a JDG, you need software that issues invoices through it. Our guide to KSeF covers what is required.
Common questions
Can I have a full-time job and a JDG at the same time? Yes. If your salary is at least the minimum wage, you do not have to pay ZUS social contributions from your JDG, only the health contribution, which you pay from both sources.
Is B2B always worth it for a programmer? Usually, at IT rates above roughly 100-120 PLN an hour (around 15,000-18,000 PLN a month net). At lower rates, or without any ZUS relief, it is worth running the numbers first.
Do I need multiple clients to keep my B2B legitimate? There is no formal requirement, but a single client raises your reclassification risk. Many contractors work for one client and remain legitimate, as long as the other markers of genuine independence are in place.
How much does running a JDG cost on top of ZUS? Bookkeeping typically runs 100-300 PLN a month, with Plumm's Starter plan starting at 149 PLN. Add the health contribution and social contributions, and minimum fixed costs usually land around 600-700 PLN a month.
Before you can invoice anyone as a contractor, you need to register a JDG. Our step-by-step guide covers the process.
Plumm calculates your ZUS, health contribution and tax automatically, tracks your deadlines, and issues KSeF-compliant invoices. Start a free trial.
This article is general information, not tax advice, and reflects the rules in force in 2026. If you are unsure which structure or tax form fits your situation, talk to an accountant before you commit.