Issuing correct VAT invoices is one of the fundamental obligations for any VAT-registered business in Poland. An invoice that is missing required fields — or contains errors — can result in the buyer losing the right to deduct input VAT, while the seller may face penalties. This guide covers everything your Polish VAT invoices must contain in 2026.
Mandatory Fields on a Polish VAT Invoice
Under Polish VAT law (the PTU Act), every VAT invoice must include the following information:
Seller Information
- Full legal name and address of the seller
- Seller's Tax Identification Number (NIP)
Buyer Information
- Full legal name and address of the buyer
- Buyer's NIP (required for B2B transactions; for B2C, only if the buyer requests an invoice)
Invoice Identification
- A sequential invoice number — each invoice must have a unique number within a defined series
- Date of issue of the invoice
- Date of supply (or date of receipt of payment if different from the issue date)
Transaction Details
- Description of goods or services supplied (name and quantity, or scope of service)
- Unit price excluding VAT (net price)
- Value of discount or price reduction, if applicable
- Net value of the supply (quantity × unit net price, minus discounts)
- Applicable VAT rate (23%, 8%, 5%, 0%, or exempt)
- Total VAT amount in PLN
- Total gross value of the invoice (net + VAT)
Invoicing Deadline
In 2026, a VAT invoice must be issued by the 15th day of the month following the month in which the goods were supplied or the service was performed. For advance payments, the invoice must be issued within 15 days of receiving the payment.
You may also issue an invoice up to 30 days before the supply date — for example, when billing in advance for a subscription service.
Correction Invoices (Faktury Korygujące)
If you need to correct an already-issued invoice — for example, because of a pricing error, a return of goods, or a granted discount — you must issue a faktura korygująca (correction invoice). This document must reference the original invoice number and date, and clearly state what has changed and the corrected values.
The buyer must confirm receipt of the correction invoice before you can reduce your output VAT. This confirmation can be an email acknowledgement, a signed document, or in the case of KSeF invoices, an automatic system confirmation.
KSeF — The National e-Invoicing System
Poland is rolling out the Krajowy System e-Faktur (KSeF), a centralised government platform for issuing and receiving structured electronic invoices. Following delays, the mandatory KSeF rollout schedule in 2026 is:
- 1 February 2026 — mandatory for large enterprises (turnover above 200 million PLN in 2023)
- 1 April 2026 — mandatory for all other VAT-registered active taxpayers
- Entities with VAT exemption: deadline to be confirmed
Under KSeF, every invoice receives a unique numer KSeF from the system. Paper and PDF invoices are phased out for B2B transactions. Invoices must be submitted to the KSeF platform in an XML format (FA(2) schema), and buyers can download them directly from the system.
Non-compliance with KSeF after the mandatory date can result in financial penalties of up to 100% of the VAT shown on the non-compliant invoice.
Invoices Without VAT (Zwolnienie)
If you issue invoices under a VAT exemption (zwolnienie podmiotowe below the 200,000 PLN threshold, or zwolnienie przedmiotowe for exempt activities), your invoice must still include most mandatory fields but will not show a VAT amount. Instead, it must indicate the legal basis for the exemption.
B2C Invoices
For sales to private individuals (non-VAT-registered), you are not obliged to issue a VAT invoice unless the customer specifically requests one. When a customer requests an invoice within 3 months of the sale, you must issue it. For online sales above certain thresholds, cash register receipts with the customer's NIP number serve as simplified invoices.
Common Errors That Invalidate Invoices
- Missing or incorrect NIP numbers
- Applying the wrong VAT rate to a supply
- Not issuing a correction invoice after returning goods
- Using non-sequential numbering that breaks the invoice series
- Issuing invoices more than 30 days before supply or more than 15 days after the month of supply
Calculate VAT on your invoices: Use the Liczbnik.pl VAT Calculator to split any gross amount into net and VAT at the correct Polish rate — ideal for checking your invoices before sending.