Invoices submitted to Poland's mandatory KSeF electronic invoicing system cannot be cancelled — once sent to the system and processed without rejection, they enter legal circulation immediately and can only be corrected, not withdrawn.
When an invoice becomes legally binding
Under Article 106na of Poland's VAT Act, a structured e-invoice is deemed issued on the date it is sent to KSeF and received when the system assigns it an identifying number. Successful processing without technical rejection is sufficient to introduce the invoice into legal circulation — even if the underlying transaction was never completed.
This draws a hard line between cancellation and correction. Cancellation requires two conditions to be met simultaneously: the invoice must not have entered legal circulation, and it must document a genuinely unperformed transaction. Once KSeF accepts an invoice, the first condition cannot be met — the invoice is already in circulation.
Correction procedure
For KSeF invoices documenting non-existent transactions, sellers must issue a correcting invoice that zeros out the original rather than cancelling it. This differs from pre-KSeF practice, where a physical invoice could be annotated and crossed out before delivery to the counterparty.
KSeF also eliminates the buyer's option to issue corrective notes for invoice errors — Article 106k was repealed from February 1, 2026. Correction responsibility now rests solely with sellers under Article 106j of the VAT Act.
A separate risk applies to phantom invoices left uncorrected: under Article 108, any person who issues an invoice showing a VAT amount is liable to pay that tax, regardless of whether any transaction occurred.
Context
The mandatory KSeF regime applied to large taxpayers from February 1, 2026 and to all other VAT-registered businesses from April 1. The smallest taxpayers — those with monthly sales below PLN 10,000 gross — have until January 1, 2027.
The core shift: digital transmission, not physical delivery, now determines when an invoice enters legal circulation — eliminating the traditional option of controlling invoice validity through paper handling before handing documents to a counterparty.