The Polish tax authority has provided new guidance on how businesses should handle invoices that are mistakenly submitted through the National e-Invoicing System (KSeF). The clarification confirms that once an invoice has been accepted and assigned a KSeF number, it cannot simply be deleted or withdrawn. Any errors must instead be resolved through the formal correction process.
While the ruling relates to a specific case, it provides valuable guidance for organisations preparing for mandatory KSeF. It reinforces the importance of validating invoice data before submission and establishing clear procedures for correcting mistakes once invoices have entered the system.
What has been clarified?
The guidance follows an individual tax ruling concerning a business that accidentally submitted an invoice to KSeF that should not have been transmitted through the platform.
After KSeF accepted the invoice and assigned it an identification number, the taxpayer asked whether the document could simply remain in the system without further action.
The Polish tax authority concluded that this is not possible.
According to the ruling:
- invoices assigned a KSeF number have entered legal circulation;
- invoices registered in KSeF cannot be deleted or cancelled;
- errors must be corrected through a corrective invoice;
- in the specific case addressed by the ruling, the corrective invoice should reduce the original invoice value to zero.
This clarification confirms that KSeF is more than a transmission platform. Once an invoice has been accepted, it forms part of the official invoicing record.
Why this matters
For organisations implementing KSeF, this guidance highlights an important operational aspect of the clearance model.
Unlike traditional invoicing environments, accepted invoices cannot simply be removed from the system if a mistake is discovered afterwards. Businesses therefore need robust controls before submission and well-defined correction procedures for situations where errors occur.
This makes invoice validation an increasingly important part of the end-to-end invoicing process.
Practical implications for organisations
As businesses continue preparing for mandatory KSeF, several practical considerations become increasingly important.
Validate invoice data before submission
Because invoices cannot be deleted once accepted, organisations should minimise the risk of incorrect submissions through strong validation of master data, VAT treatment and invoice content.
Establish clear correction procedures
Finance teams should understand when corrective invoices are required, how they should be issued and how these corrections affect downstream accounting processes.
Review ERP and e-invoicing integrations
ERP systems and e-invoicing solutions should support pre-submission validation wherever possible, helping organisations prevent avoidable errors before invoices are sent to KSeF.
Earlier KSeF developments
This clarification builds on previous guidance published by the Polish Ministry of Finance as organisations prepare for mandatory e-invoicing.
To better understand the broader KSeF framework, read our previous articles:
What, why and when? KSeF explained
Poland finalises KSeF regulations ahead of the 2026 mandate
Changes companies need to implement
Although this clarification does not introduce new legislation, it provides practical guidance on how organisations should operate within the KSeF framework.
Companies preparing for mandatory KSeF should:
- validate invoices before submission;
- implement documented correction procedures;
- ensure ERP and e-invoicing solutions support robust pre-submission validation;
- train finance teams on the legal consequences of invoices accepted by KSeF.
As Poland moves closer to mandatory e-invoicing, this clarification reinforces an important principle: once an invoice has been accepted by KSeF, correcting it remains possible, but deleting it does not.
