Poland

Poland has moved to a central clearance model for B2B invoicing. Invoices are no longer sent directly between businesses. Instead they are issued in KSeF (Krajowy System eFaktur), the national e-invoicing system run by the Ministry of Finance, and the buyer collects them from there.

An invoice only exists legally once KSeF has accepted it and assigned a unique KSeF number. This gives the tax authority real-time visibility of every B2B invoice and supports Poland's fight against VAT fraud, which already led to tools such as JPK (SAF-T) reporting and the split payment mechanism. KSeF started as a voluntary system in 2022. After several delays, it became mandatory in phases during 2026, and the final group joins in 2027. For businesses with Polish entities, KSeF is now a core part of invoicing operations.

The mandate covers businesses with a registered office or fixed establishment in Poland, for B2B invoices. Phasing depends on size. The largest taxpayers started first in February 2026, other businesses followed in April 2026, and the smallest join in January 2027 (verify the phases and thresholds).

Foreign businesses that are only VAT-registered in Poland, without a fixed establishment, are generally not required to issue invoices through KSeF, but they may choose to. B2C invoices remain outside the mandatory scope, although they can also be issued through KSeF.

Every in-scope invoice must be created in the structured FA(3) format and sent to KSeF, which validates it and assigns a KSeF number. The ERP must store this number and use it in payment references and corrections. Businesses must also set up authorisations, using tokens, certificates or qualified signatures, so that the right people and systems can act in KSeF on the company's behalf.

Page 2 of 16 HubBroker – Country pages: PL, FI, HR, NL, UK, GR Inbound invoices must be fetched from KSeF rather than received by email. When KSeF is unavailable, there are offline and emergency procedures. Invoices issued offline must carry a QR code and be sent to KSeF within the set deadline (verify the rules). A PDF can still be shared with a customer as a visual copy, but it is not the legal invoice.

KSeF uses its own national XML schema, FA(3) (verify the current version). Unlike Peppol formats, it is not based on UBL or EN 16931, so ERP data must be mapped specifically to the Polish structure.

The infrastructure is a single central platform. Businesses connect to KSeF through its API, either directly or through a service provider. For public-sector invoicing, Poland also runs the PEF platform, which is connected to Peppol.

HubBroker connects your ERP to KSeF through its API. We map your invoice data to the FA(3) schema, validate it before submission, and return the KSeF number and status to your ERP, so your records and payment references stay correct. Inbound invoices are fetched from KSeF automatically and delivered to your ERP as structured data, ready to post.

This replaces manual downloads and email handling, and helps your accounts payable team keep up with the new process. For international groups with Polish entities, this means Poland can run from the same ERP as the rest of the group. HubBroker handles the Polish format and the KSeF connection, and you keep control of your invoicing process.