E-invoicing in Poland

Poland is moving into mandatory B2B e-invoicing through the National e-Invoicing System, KSeF. After postponements and redesign work, the mandatory KSeF 2.0 rollout begins in 2026, with large businesses first and the rest of the in-scope B2B market following shortly after.

KSeF is a central platform model. That means compliance depends not only on producing the correct XML structure, but also on authentication, submission, validation, receipt confirmation, exception handling and integration with internal finance processes.

At a glance

B2B e-invoicing

Mandatory rollout in 2026

First wave

Businesses above the PLN 200 million sales threshold from 1 Feb 2026

Second wave

Remaining in-scope B2B businesses from 1 Apr 2026

Core platform

Krajowy System e-Faktur (KSeF)

Format

Polish structured invoice schema, including FA(3) for the mandatory period

B2G

Public e-invoicing channels remain relevant, with KSeF/PEF interaction evolving

What the mandate means

In-scope businesses must issue structured invoices through KSeF and manage the tax authority platform response as part of their invoice lifecycle. The invoice becomes part of a centralised national process, so businesses need a reliable connection, strong controls and a fallback strategy for outages or rejected files.

Foreign businesses should assess whether they have a Polish fixed establishment or other in-scope status. Polish e-invoicing scoping can be highly fact-specific, especially for VAT-registered but non-established entities.

Timeline

2024: Earlier mandatory date postponed and KSeF redesign launched

2025: KSeF 2.0 documentation, schema and implementation work progressed

1 Feb 2026: Mandatory KSeF begins for the largest taxpayers

1 Apr 2026: Mandatory KSeF extends to remaining in-scope B2B taxpayers

What businesses should do now

Poland should be treated as a high-priority ERP integration project. Businesses should:

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Test FA(3) mapping, permissions and authentication, customer master data, split payment indicators, VAT codes, invoice correction flows, attachments, offline procedures

Reconciliation between KSeF status and ERP posting status

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Frequently asked questions

Is KSeF the same as sending an XML file by email?

No. KSeF is a central government platform. The invoice must be submitted to and processed through KSeF according to the applicable technical and legal rules.

Can businesses wait until April 2026?

Only businesses outside the first wave may be able to rely on the later date. Large taxpayers should be ready for 1 February 2026, and all in-scope businesses need testing well before their go-live date.

Sources:‍

Polish Ministry of Finance: KSeF mandatory period

Polish Ministry of Finance: KSeF information portal

European Commission: eInvoicing in Poland

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