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KSeF and FA_VAT: E-Invoicing in Poland

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docs101 currently supports ZUGFeRD/Factur-X only. KSeF/FA_VAT support for the Polish market is planned for a future release. Businesses based in Poland cannot use docs101 for compliant invoicing at this time.

Poland is introducing a centralized e-invoicing platform called KSeF (Krajowy System e-Faktur — National E-Invoice System). Like Italy's SDI, KSeF operates as a clearance system where invoices must be submitted to and validated by a government platform before they are considered legally issued.

What is KSeF?​

KSeF is a government-operated centralized platform for the issuance, storage, and retrieval of structured electronic invoices in Poland. It is maintained by the Polish Ministry of Finance and the National Revenue Administration (Krajowa Administracja Skarbowa — KAS).

KSeF has been available on a voluntary basis since January 2022, allowing businesses to familiarize themselves with the system before mandatory adoption.

What is FA_VAT?​

FA_VAT is the XML schema used for invoices within the KSeF system. It defines the structure and data fields that every electronic invoice must contain. The schema is Poland's structured invoice format, aligned with the EN 16931 standard.

The current version being prepared for the mandatory rollout is FA(3), which takes effect on February 1, 2026. This version introduces refinements to the schema based on feedback from the voluntary adoption period.

How It Works​

The KSeF process follows a clearance model:

  1. Invoice creation: The supplier creates an invoice conforming to the FA_VAT XML schema
  2. Submission: The invoice is submitted to KSeF via the platform's API or through an authorized intermediary
  3. Validation: KSeF validates the invoice against the schema and Polish tax rules
  4. Assignment: Upon successful validation, KSeF assigns a unique reference number (numer KSeF) to the invoice
  5. QR code: A QR code can be generated that links to the invoice in KSeF, allowing third-party verification
  6. Retrieval: The recipient retrieves the invoice from KSeF using the reference number, automated API access, or token-based authorization
  7. Storage: KSeF stores all validated invoices for 10 years

The unique reference number and QR code allow any third party (e.g., a tax auditor or business partner) to verify the authenticity of an invoice against the central system.

Mandatory Timeline​

The rollout follows a phased approach based on business size:

  • February 1, 2026: Mandatory for large taxpayers (those with 2024 turnover exceeding PLN 200 million, approximately €46 million)
  • April 1, 2026: Mandatory for all other VAT-registered taxpayers
  • January 1, 2027: Extended to micro-entrepreneurs and small firms with monthly sales up to PLN 10,000

Transition Period​

To ease the transition, no financial penalties will be imposed for non-compliance until January 1, 2027. This gives businesses time to integrate their systems with KSeF while the mandate is already technically in effect.

Technical Details​

FA_VAT Schema​

The FA_VAT schema defines the required structure for KSeF invoices. Key elements include:

  • Supplier and customer identification: NIP (Polish tax ID), name, address
  • Invoice metadata: Invoice number, issue date, sale date, currency
  • Line items: Description, quantity, unit, unit price, net amount, VAT rate, VAT amount, gross amount
  • VAT summary: Breakdown by VAT rate with totals
  • Payment information: Payment method, bank account, due date
  • Legal remarks: Reverse charge indicators, split payment annotations, tax exemption codes

API Integration​

KSeF provides a REST API for automated invoice submission and retrieval. Businesses can integrate directly or use authorized intermediaries. The API supports:

  • Invoice submission: Single invoice or batch upload
  • Status checking: Query the processing status of submitted invoices
  • Invoice retrieval: Download invoices by reference number or date range
  • Session management: Authentication via qualified electronic signatures or trusted profiles

Authentication​

Access to KSeF requires authentication via:

  • Qualified electronic signature (kwalifikowany podpis elektroniczny)
  • Trusted profile (profil zaufany) — Poland's national digital identity system
  • Authorization tokens issued to automated systems

Scope of the Mandate​

What is Covered​

  • All domestic B2B transactions between Polish VAT-registered entities
  • Invoices issued by Polish entities to Polish consumers (B2C) where an invoice is requested

What is Excluded​

  • Invoices issued by entities not registered for VAT in Poland
  • Certain simplified invoices (e.g., tickets, receipts up to PLN 450)
  • Cross-border invoices to non-Polish recipients (though these may be reported through KSeF in a future phase)

Relationship to EN 16931​

The FA_VAT schema is aligned with EN 16931 and incorporates Peppol BIS conventions. However, it contains additional fields specific to Polish tax requirements, such as:

  • Polish NIP tax identification numbers
  • Split payment mechanism indicators (required for certain high-value transactions in Poland)
  • GTU codes (goods and services group codes for specific transaction categories)
  • References to previous invoices for corrections

Key Differences from Other Systems​

AspectKSeF (Poland)SDI (Italy)ZUGFeRD (Germany)
ModelClearanceClearanceDecentralized
FormatFA_VAT XMLFatturaPA XMLPDF + CII XML
Central storage10 yearsYes (via Agenzia)No (supplier stores)
QR verificationYesNoNo
Mandatory sinceFeb 2026Jan 2019Receiving: Jan 2025
Penalty grace periodUntil Jan 2027NoneN/A

Learn More​