Mandatory since 2026

E-invoicing in Poland, compliant through KSeF

Since 2026, Polish businesses must issue and receive invoices through the national KSeF system. Invoicier sends and receives compliant FA(3) invoices through KSeF, so you are covered in minutes.

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KSeF and Peppol e-invoicing

Is e-invoicing mandatory in Poland?

Yes. Since 1 February 2026 large taxpayers, and since 1 April 2026 all other VAT-registered businesses, must issue and receive structured invoices through KSeF (Krajowy System e-Faktur). The smallest micro-businesses follow from 1 January 2027.

How e-invoicing works in Poland

Poland's e-invoicing runs through KSeF (Krajowy System e-Faktur), the national clearance platform operated by the Polish Ministry of Finance. Every B2B invoice must be issued to KSeF, which validates it and assigns a unique KSeF identification number. An invoice is only legally issued once KSeF accepts it.

Invoices use the structured FA(3) XML schema, which replaced FA(2) on 1 February 2026. KSeF is a national system, separate from the Peppol network used elsewhere in Europe, and businesses are identified by their NIP (tax identification number).

Peppol still matters for Poland: it is used for cross-border invoices to and from suppliers in other Peppol countries. Invoicier handles both, sending and receiving FA(3) through KSeF and connecting you to Peppol for international invoicing.

E-invoice formats and standards in Poland

Polish e-invoices use the FA(3) schema and clear through KSeF. Invoicier generates and validates them for you.

FA(3)
The current structured Polish e-invoice XML schema, mandatory in KSeF since 1 February 2026 (replacing FA(2)).
KSeF (Krajowy System e-Faktur)
The national clearance platform every B2B invoice must pass through to be legally issued.
Peppol BIS Billing 3.0
Used for cross-border invoices to and from Polish businesses, alongside the domestic KSeF flow.

Invoice identifiers in Poland

Polish businesses are identified in KSeF by their tax number, and each cleared invoice receives a KSeF number.

NIP 1234567890
The Polish tax identification number used to identify businesses in KSeF.
KSeF number 1234567890-20260213-ABCDEF123456-7C
The unique identifier KSeF assigns to each invoice once it is validated and accepted.

Poland e-invoicing timeline

2022

KSeF voluntary

KSeF launches as a voluntary national e-invoicing system.

February 2026

Large taxpayers

KSeF becomes mandatory for businesses above 200 million PLN turnover. The FA(3) schema replaces FA(2).

April 2026

All B2B businesses

KSeF becomes mandatory for all other VAT-registered businesses, including SMEs and sole traders.

January 2027

Micro-businesses

The smallest taxpayers, with the lowest-value invoices, are brought into the KSeF mandate.

How Invoicier gets you invoicing in Poland

No ERP migration, no paperwork. Sign up and start sending compliant invoices.

1

Create your account

Sign up with your email. No credit card, no lengthy onboarding.

2

Add your Polish company

Enter your company details and NIP, and we set up your connection to KSeF.

3

Send your first invoice

Create an FA(3) invoice and Invoicier issues it through KSeF, which returns the KSeF number.

4

Receive invoices automatically

Invoices issued through KSeF, and cross-border invoices over Peppol, arrive in your dashboard.

Start free, no credit card

Why send Polish e-invoices with Invoicier

FA(3) and KSeF handled for you, with Peppol for cross-border, and none of the ERP complexity.

Compliant by design

Issue and receive valid FA(3) invoices through Poland's KSeF, exactly as the Ministry of Finance requires.

Live in minutes

No ERP migration or paperwork. Sign up, add your NIP, and send your first invoice.

KSeF handled for you

We connect you to KSeF and manage clearance, returning the KSeF number for each invoice.

Cross-border ready

Send and receive invoices with suppliers abroad over Peppol, all in one place.

E-invoicing in Poland: frequently asked questions

KSeF e-invoicing is mandatory in Poland

Start issuing compliant FA(3) invoices today. It takes minutes.

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