116 days
Poland: KSeF becomes mandatory for the smallest micro-entrepreneurs; penalties start
The smallest Polish sole traders and micro companies; all Polish businesses regarding penalties.
Poland: KSeF e-invoicing mandatory for all VAT taxpayers (except the smallest micro-firms)
159 days ago (In force)
Date note: Large taxpayers (2024 sales above PLN 200M) started 2026-02-01; penalties for KSeF errors suspended until 2027-01-01
What changes
Since 1 April 2026 all businesses in Poland must issue B2B invoices through the National e-Invoicing System (KSeF) in the FA(3) XML schema; the system assigns the legal invoice number and the buyer receives it via KSeF. Only micro-entrepreneurs with monthly sales up to PLN 10,000 have until 2027. Paper and PDF invoices are no longer valid B2B invoices.
Who is affected
Every VAT-registered business in Poland, including foreign companies with a Polish fixed establishment.
Sizes: micro, small, medium, large · Sectors: All sectors · Applies if: We invoice other businesses (B2B)
What to do
Connect your ERP or invoicing tool to KSeF 2.0 with authentication tokens or a qualified signature, implement the FA(3) schema and offline24 fallback mode, and train staff on retrieving purchase invoices from KSeF. Use the 2026 penalty-free period to fix errors.
Penalty
Penalties for non-compliance apply from 2027-01-01
Sources
- Polish Ministry of Finance – KSeF portal (ksef.podatki.gov.pl)
- EY – Poland signs into law mandatory national e-invoicing system (www.ey.com)
- ecosio – E-invoicing in Poland: 7 topics for 2026 (ecosio.com)
Last verified 7 September 2026. Informational only, not legal advice.