Starting a B2B cooperation in Poland: how to begin, what to sign, and what it costs in the first year

You start a B2B cooperation in Poland by agreeing a net rate, opening a JDG (jednoosobowa działalność gospodarcza, a sole trader business) and registering with ZUS, then sending your first invoice. Most of the paperwork fits into one evening online, and the first deadlines fall on the 15th and the 20th of the month after you start.

Before you say yes: three checks

Settle these before you agree a start date.

1. Is the rate net? Agree in writing that the rate is “net, plus VAT” if you will charge VAT. To compare it with a salary, remember that a job costs the employer roughly 1.2 times the gross salary, and that on B2B a day off is usually unpaid. B2B or an employment contract has a worked example.
2. Is the client your employer, now or last year? Then ryczałt (the lump-sum tax) is lost if you did that work as their employee this year or last year, the 19% flat tax is lost for the year if you also did it as their employee this year, and the ZUS start-up reliefs do not apply. Redo the numbers first.
3. Can you run a business here? EU, EEA, Swiss and US citizens can open a JDG like Poles. Other foreigners need a status on the law’s list; a work permit is not enough. See how a foreigner opens a JDG.

Read the draft contract before you register. What a B2B contract should contain lists the clauses to check, and the 2026 reclassification rules explain why fixed hours and a boss in the contract are a risk.

Week one: register your business

1. Get a way to log in. Online filing goes through login.gov.pl, the national login gateway, with a profil zaufany (trusted profile, free), an e-ID card or a qualified e-signature. A trusted profile needs a PESEL, the 11-digit national number.

2. Decide before you open the form. Have these ready:

• PKD code, the activity code from the PKD 2025 list. Most programmers choose 62.10.B.
• Tax form: the tax scale (12% and 32%) applies unless you choose the 19% flat tax or ryczałt (12% of revenue for software development). You can choose in the form, or by the 20th of the month after your first revenue. Choosing your tax form compares them.
• ZUS: ulga na start (the 6-month start-up relief), preferential ZUS, or “I am insured abroad”.
• An email address for e-Doręczenia, the official electronic mailbox.

3. File in CEIDG (the public register of sole traders) on biznes.gov.pl. It is free, and one application also gets you a NIP (tax number) and a REGON (statistics number) and passes your data to ZUS. From 1 November 2026 a new registration must be filed electronically: a paper application handed in after 31 October 2026 is not examined. Your start date can be the day you file, not earlier, and the entry normally appears by the next business day.

4. Set up e-Doręczenia in the same form. Every business in CEIDG must have an e-Doręczenia address since 1 October 2026. Give your email and accept the terms in section 22.1, and the public provider sets it up free.

5. Register with ZUS within 7 days. Attach the form to the CEIDG application, or send it within 7 days of your start date: ZUS ZZA for ulga na start (health insurance only), ZUS ZUA for preferential ZUS. ZUS then sends you your personal contribution account number (NRS). If another EU country insures you, take your A1 certificate to ZUS instead.

For foreigners: from 1 November 2026 you need a PESEL, or the identifier from an EU country’s eID scheme, to register. biznes.gov.pl warns that checking a foreigner’s status can take up to 30 days, usually about 7. Build that into your start date.

Weeks two and three: get ready to be paid

6. Decide on VAT. In 2026 you can stay VAT-exempt while your net sales stay within 240,000 PLN a year, cut by the days left if you start mid-year. Legal and advisory services can never be exempt. If you choose VAT, file VAT-R (free) before your first taxable sale; you can attach it to the CEIDG application. If any client is a business in another EU country, you also need VAT-UE registration before the first invoice, even if you are exempt.

7. Open a bank account for the business. The law does not require a separate business account. But a single deal between businesses worth more than 15,000 PLN must be paid through a payment account, and the VAT white list (the public list of VAT payers’ accounts) shows only business accounts. If you charge VAT and Polish clients pay you more than 15,000 PLN at a time, you need a Polish business account on that list in practice.

8. Set up KSeF, the national e-invoice system. Log in to the Ministry’s free Aplikacja Podatnika KSeF at ap.ksef.mf.gov.pl through login.gov.pl (mObywatel, your bank or a trusted profile). As the owner of a JDG you have full rights automatically. Until 31 December 2026 you may still send PDF invoices while your KSeF-obligatory invoices stay at or below 10,000 PLN gross in a month. Many monthly B2B invoices are above that, so plan for your first invoice to go through KSeF. From 1 January 2027 there is no exception.

Your first month-end

9. Invoice by the 15th of the following month. The contract may ask for it earlier. Check the client’s legal name and NIP before you send: KSeF needs the NIP to deliver the invoice.

10. Pay ZUS by the 20th. File ZUS DRA and pay one transfer to your NRS. On ulga na start you still pay the health contribution, in full for every month you run the business, including the first.

11. Pay income tax by the 20th to your mikrorachunek podatkowy (micro tax account, generated from your NIP), or after each quarter: a new business may pay quarterly. On the tax scale nothing is due until your income since 1 January passes 30,000 PLN. A VAT payer also files JPK_V7M and pays VAT by the 25th.

When the 20th or the 25th falls on a weekend or public holiday, the deadline moves to the next working day.

What the first year costs in 2026

Registration, e-Doręczenia, VAT-R and the Ministry’s KSeF tools are free. What you pay each month, at 2026 rates, before income tax:

Two worked totals for a first year at 2026 rates, before income tax and the accountant:

• Flat tax or tax scale: at least 7,715.64 PLN (6 × 420.86 social, 12 × 432.54 health). More once 9% or 4.9% of your income is above the minimum.
• Ryczałt, revenue above 60,000 PLN: a full year at 830.58 PLN of health plus six months of preferential ZUS comes to 12,492.12 PLN. You pay 498.35 PLN until the month your revenue passes 60,000 PLN.

The amounts change on 1 January 2027, because the minimum wage rises to 4,950 PLN; ZUS publishes the new figures each year. After the 30 months comes full ZUS, 1,788.29 PLN a month in 2026, or Mały ZUS Plus if last year’s revenue was at most 120,000 PLN. Ulga na start and preferential ZUS explains the conditions, including that you cannot add sickness cover during ulga na start.

What to sign, and what to keep

Sign:

• The B2B contract, in writing, with your business name and NIP once your CEIDG entry is live. Check the rate, payment term, notice, liability and penalties.
• An NDA, if the client asks for one. Check what counts as confidential, how long it lasts after the contract ends, and whether it carries contractual penalties (kary umowne), which the client can claim whatever the actual loss.
• A copyright transfer, for code, designs or texts. It must be in writing or it is void, and it covers only the uses it lists. It can sit in the contract or in a separate document, ideally passing the rights on payment.

Be wary of side documents copied from an employee handbook, such as holiday approval or fixed hours: they are what a labour inspector reads as a job.

Keep: the CEIDG confirmation you get by email, the ZUS letter with your NRS, the signed contract and every annex, and every invoice and bank statement, filed by month. Tax records must be kept for 5 years from the end of the year the tax was due. Komplet, our free Mac app, files each invoice into the right month and pairs it with the payment on your bank statement.

Your first two months at a glance

An example: you file in CEIDG on Monday 2 November 2026 with ulga na start and ryczałt, and invoice one Polish client monthly.

Because you started after the 1st, November does not count towards the six months of ulga na start: they run from December 2026 to May 2027, and preferential ZUS starts in June 2027.

What to do next

1. Get the contract draft and agree a net rate and a start date on or after the day you will file.
2. Set up your trusted profile. If you are a foreigner without a PESEL, get one first: it is required from 1 November 2026.
3. File in CEIDG with ZUS, e-Doręczenia and, if needed, VAT-R in one go.
4. Log in to KSeF and open the bank account before your first invoice.
5. Put the 15th (invoice) and the 20th (ZUS and tax) in your calendar every month.