How to Invoice as a B2B Contractor in Poland: Step-by-Step Guide
Invoicing might seem like the simple part of running a B2B business in Poland — but there are strict legal requirements for what a valid Polish invoice must contain. An invoice missing required elements can be challenged by the tax authority or rejected by your client's accounting department.
This guide covers everything you need to know about creating, sending, and enforcing invoices as a Polish sole proprietor (JDG).
What Is a "Faktura VAT"?
In Polish, a business invoice is called a Faktura (or Faktura VAT if it includes VAT). It is the primary document confirming a business transaction and is required for:
- Tax purposes (calculating your income/revenue for tax declarations)
- VAT accounting (both your output VAT and client's input VAT)
- Client bookkeeping
Unlike informal receipts or pro-forma invoices, a Faktura VAT has legal standing and mandatory elements defined by Polish law (the VAT Act — Ustawa o VAT).
Required Elements on a Polish Invoice
Every B2B invoice you issue in Poland must contain:
Mandatory fields
| Field | Details |
|---|---|
| Invoice number | Sequential, unique (e.g., 1/2026/03 or FV/2026/001) |
| Issue date | Date you created/issued the invoice |
| Sale/service date | Date the service was actually delivered (if different from issue date) |
| Seller name | Your full legal name (as registered in CEIDG) |
| Seller NIP | Your tax identification number |
| Seller address | Your registered business address |
| Buyer name | Client's company name or full name |
| Buyer NIP (for business clients) | Client's tax ID |
| Buyer address | Client's registered address |
| Description of services | What you actually did (be specific — "software development services per agreement dated...") |
| Net amount | Amount before VAT |
| VAT rate | Applicable rate (23%, 8%, 0%, or ZW for exempt) |
| VAT amount | Net × VAT rate |
| Gross amount | Net + VAT |
| Currency | PLN or foreign currency (must state exchange rate if non-PLN) |
| Bank account | Your business account number for payment |
| Payment deadline | Due date for payment |
If you're VAT-exempt (below 200,000 PLN threshold)
Instead of VAT amounts, include:
- "zwolnienie od podatku" (tax exemption) with the legal basis
- Or simply mark VAT as "ZW" (zwolniony — exempt)
- No VAT number required (your regular NIP is sufficient)
VAT Rates in Poland
| Rate | When it applies |
|---|---|
| 23% | Standard rate — applies to most IT services |
| 8% | Reduced rate — certain goods/services (not typically IT) |
| 5% | Books, certain food items (not IT) |
| 0% | Exports, intra-EU B2B services (reverse charge) |
| ZW (exempt) | Below 200,000 PLN annual threshold, or specific exemptions |
For most IT services invoiced to Polish business clients: 23% VAT.
For IT services to EU business clients: 0% with reverse charge (client pays VAT in their country). You must be VAT-registered and include the client's EU VAT number.
For IT services to non-EU clients (US, UK, etc.): 0% — services are outside Polish VAT territory.
Invoicing Software Options
Using dedicated invoicing software is strongly recommended — it ensures legal compliance, stores your documents, and integrates with accounting.
inFakt (infakt.pl)
- Most popular among Polish IT freelancers
- Handles ryczałt, flat tax, ZUS tracking, VAT
- Creates invoices with all required fields pre-filled
- Electronic sending and PDF export
- Cost: ~49–99 PLN/month
- Partial English interface
Fakturownia (fakturownia.pl)
- Strong multi-currency support — excellent for EUR/USD invoices
- Clean interface, good for contractors billing foreign clients
- Free tier for up to 3 invoices/month
- Paid plans: from 19 PLN/month
- Bilingual invoices (Polish + English on one document)
wFirma (wfirma.pl)
- Full accounting software (not just invoicing)
- Good for self-managing your full bookkeeping
- ~49 PLN/month
- Handles ZUS, income tax declarations, VAT returns
Faktura.pl / Fakturowania.pl
- Simple and free for basic invoicing
- Limited features; suitable for very low-volume needs
Microsoft Word / Excel templates
- Legal, but tedious to maintain sequential numbering and archiving
- Not recommended for anything beyond a handful of invoices/year
Payment Terms Best Practices
What to specify
- Standard for Polish IT contractors: 14 or 30 days from invoice date
- For new clients: Start with 14 days until trust is established
- For retainer/ongoing work: Invoice monthly, due within 14 days of issuance
Late payment consequences
Under Polish law (Ustawa o terminach zapłaty w transakcjach handlowych), if a business client pays late, you are automatically entitled to:
- Statutory interest: 11.5–13.5% annually (rate changes quarterly)
- Compensation for debt collection costs: 40 EUR (for debts under 5,000 EUR), 70 EUR (5K–50K EUR), or 100 EUR above
You do not need a contract clause for these — they apply by law. However, you must actually claim them (send a written demand for interest).
Invoicing in EUR vs PLN
Many Polish IT contractors — especially those serving foreign clients or working at EUR-denominated rates — prefer to invoice in EUR.
You can legally invoice in EUR (or any foreign currency) as a Polish JDG.
How it works for tax purposes
If you invoice in EUR, you must convert to PLN for tax purposes using the National Bank of Poland (NBP) mid-rate from the last business day before the invoice issue date.
Your accounting software (inFakt, Fakturownia) handles this conversion automatically.
Practical benefits of EUR invoicing to foreign clients
- Eliminates currency conversion risk on the client side
- Matches the standard in Western European markets
- Useful if you have EUR business account (Revolut Business, mBank)
Practical consideration
If your income is mostly EUR, hold EUR in your business account and convert when the rate is favorable rather than converting every payment immediately.
When the Client Doesn't Pay
Despite payment terms, late payment happens. Here is the escalation process:
Step 1: Reminder email
Send a polite reminder with the invoice attached on the day after the deadline. Most late payments resolve here.
Step 2: Formal payment demand (wezwanie do zapłaty)
A written letter (or email with read receipt) formally demanding payment, citing the invoice number, amount, and that interest has been accruing since the due date. State a new deadline (e.g., 7 days).
Step 3: Mediation or negotiation
If the client claims a dispute, try to resolve by invoice correction or payment plan before escalating.
Step 4: Debt collection agency
Several Polish firms (e.g., Kaczmarski, Inkasso) take B2B debt collection cases on a commission basis (typically 10–20% of recovered amount). Effective for amounts over 5,000 PLN.
Step 5: Court — Electronic Payment Order (Elektroniczne Postępowanie Upominawcze, EPU)
File online at e-sad.gov.pl. For undisputed debts, a payment order is typically issued within 1–2 months. Court fee is 1.25% of claim (minimum 30 PLN). Process is entirely online and straightforward.
Step 6: Bailiff enforcement
Once you have a court order, you can instruct a bailiff (komornik) to seize assets or garnish bank accounts.
Record-Keeping Requirements
You must keep all invoices (issued and received) for 5 years after the end of the tax year in which the invoice was issued. Electronic copies are fully legal.
Most accounting software archives everything automatically. If you're using paper or simple software, maintain a systematic folder structure: year/month/client.
Correcting an Issued Invoice
If you made an error (wrong amount, wrong NIP, wrong description), issue a Faktura Korygująca (corrective invoice) referencing the original invoice number and showing the correction.
Your accounting software will have a "correct invoice" function. The client's accounting department must also process the correction.
For the full setup checklist including business registration, ZUS, and banking, see our freelance developer guide for Poland. For VAT rules when invoicing foreign clients, see our VAT for foreign clients guide.
Polish invoicing requirements are defined in the VAT Act (Ustawa z dnia 11 marca 2004 r. o podatku od towarów i usług). Requirements can change — verify current requirements with your accountant.