Glossary Term

KSeF

KSeF (Krajowy System e-Faktur) is Poland's national e-invoice system that will become mandatory for all B2B invoicing in February 2026.

Quick Facts

country
Poland
operator
Ministerstwo Finansów
full name
Krajowy System e-Faktur
mandatory from
February 2026

Definition

What is KSeF?

KSeF (Krajowy System e-Faktur / National E-Invoice System) is Poland's central repository for all e-invoices. It becomes mandatory for all VAT-registered businesses in February 2026.

Key Features

  • Central Repository: All invoices stored for 10 years

  • Unique KSeF Number: Every invoice gets a unique identifier

  • Real-time Reporting: Tax authority sees all invoices immediately

  • Structured Format: FA schema (XML)

    • How It Works

    1. Submission: Submit invoice XML to KSeF via API or portal
    2. Validation: KSeF validates against FA schema
    3. Assignment: KSeF assigns unique number
    4. Access: Buyer retrieves invoice from KSeF (not sent directly)

    Key Requirements

  • Valid NIP for both parties

  • Sequential invoice numbering

  • Submission within 30 days of issue date

  • GTU codes for certain goods/services