KSeF in Poland: e-invoicing through the state system

What is different

The dates in this article are as the rules stood in October 2026. The rollout in Poland is staged in 2026, and the smallest businesses follow from 1 January 2027. Check the Polish Ministry of Finance (Ministerstwo Finansów) for exact dates per type of business, because the stages depend on turnover and status.

In the Peppol model you send to an access point, and the recipient picks up the invoice there. In KSeF the invoice goes through the state's system. The system checks the invoice, assigns it a number and makes it available to the recipient. This is a so-called clearance model.

The clearance model in Business Central

Microsoft Learn describes the clearance model in connection with setting up e-documents. Here the seller has to get the invoice approved by a tax authority or a certification party before it is sent to the customer. Countries such as Spain, India, Mexico and Italy are mentioned as examples.

Microsoft also writes that the support in Business Central is only a framework. You must build or acquire an extension that fits the country's requirements, and use it as a service integration. There is a field where you mark that the service is a clearance service, and that requires you to have chosen a dedicated service integration.

What we have not been able to confirm

Poland is not on Microsoft's list of supported localizations for E-Documents on Microsoft Learn, as it stood in October 2026. We have not been able to confirm that the standard version of Business Central connects to KSeF by itself.

Before you count on it, you should therefore ask your partner and search Microsoft AppSource for extensions for KSeF. Ask specifically which document types it covers, how errors are handled, and how invoices received through KSeF end up as purchase documents.

What you should prepare

• Find out which stage your Polish entity or customers belong to.
• Clarify whether you must send through KSeF yourselves, or only receive.
• Check how your Polish customers will receive invoices.
• Agree who can correct master data quickly when an invoice is rejected.
• Test with a few invoices before you move the full volume.

When an invoice is rejected

With a state system there is a rejection process. Business Central's E-Documents keeps status and a log for each document, so you can see where an invoice is stuck. A clear internal routine for who corrects, and how quickly, is at least as important as the technical connection itself.

Remember also that rules for retaining e-documents may be set in the country's legislation. E-Documents has setup for retention policies for logs and data, but you are the one who must know how long to keep them.

Talk to those who will use it, and next steps

Ask your Polish customers whether they expect to receive invoices through KSeF, and who on their side works with it. Also ask whether they require particular information on the invoice that is not standard at your company.

Ask your auditor or tax adviser in Poland which stage you belong to. The rules are staged, and a wrong guess can mean that you either start too late or spend time on something that does not apply yet.

We can help find out what your setup requires. We are working on an e-invoicing app for Business Central. It is an idea under development, it is not available, and it has no price or date. You can see what we are working on at the link below.