SMB Operations|31 Jul 2026
KSeF e-invoicing became mandatory for most Polish companies on 1 April 2026, but tax offices will not fine mistakes or n
The Story
on-use until 1 January 2027.
Why It Matters
This is a genuine no-penalty runway, not a delay of the obligation itself. From 1 January 2027 an invoice issued outside KSeF can carry a fine of up to 100% of the VAT shown on it, or 18.7% of the total value on a non-VAT invoice. Every mistake made and fixed before that date costs nothing; the same mistake made in 2027 can cost real money.
What To Do About It
If your invoicing software or accountant has not run a full KSeF cycle yet, issuing and receiving, do it in the next few weeks while errors carry no fine. Ask your accountant directly whether your firm has issued a live KSeF invoice yet or only tested the connection, those are not the same thing.
ksefe-invoicingvat penaltypolish taxministry of financeaccounting compliance