No financial penalties during 2026 grace period. From January 1, 2027: up to 100% of VAT on invoice, or 18.7% of gross for non-VAT invoices per the KSeF implementation plan .
Invoice Attachment Violations
Including prohibited content (marketing materials, contracts, price lists) in KSeF invoice attachments may result in revocation of attachment issuance rights per KSeF 2.0 regulations.
Standards:
EN 16931
Supported Formats:
Peppol BIS 3.0
KSeF XML (FA(3) schema)
Clearance Model:
Clearance model via KSeF. Invoices legally valid only after submission, validation, and timestamping by Ministry of Finance. UPO (Urzędowe Poświadczenie Odbioru) provides legal proof of clearance.
Archiving Requirements:
10 years retention via KSeF central platform operated by Ministry of Finance; businesses not required to maintain separate archive for KSeF-issued invoices; UPO (official acceptance receipt) stored alongside invoice XML; offline mode invoices must be uploaded within 24 hours.
Taxpayers must submit notification via e-Urząd Skarbowy before issuing invoices with attachments in KSeF 2.0. Notification must include: activity types, expected monthly volume, and average file sizes. Attachments restricted to tax-related information only (per Article 106e(1) of VAT Act). Violation may result in revocation of attachment rights.
KSeF mandatory for large taxpayers
1 February 2026
B2B
Companies with annual revenue exceeding PLN 200 million must use KSeF for B2B invoicing.
KSeF mandatory for all taxpayers
1 April 2026
B2B
Full KSeF roll-out for all VAT-registered businesses (except micro-entrepreneurs with monthly sales ≤PLN 10,000).
KSeF mandatory for micro-entrepreneurs
1 January 2027
B2B
Micro-entrepreneurs (monthly sales ≤PLN 10,000, individual invoices ≤PLN 450) must use KSeF from January 1, 2027.
KSeF penalty enforcement begins
1 January 2027
Domestic
Financial penalties for KSeF non-compliance take effect. Up to 100% of VAT amount on the invoice, or 18.7% of the gross amount for non-VAT invoices.
ViDA: Cross-border B2B DRR
1 July 2030
Intra-EU
Digital Reporting Requirements affect cross-border B2B transactions.
ViDA: Domestic Alignment
1 January 2035
Domestic
Member States must align domestic digital real-time transaction reporting with EU standards.