Poland’s Ministry of Finance plans to extend the deferral of penalties for errors in using the National e-Invoicing System, KSeF, until 31 December 2027. The announcement follows feedback from businesses, industry organisations and tax experts as they adapt to the system.
The proposed extension still requires a change in law. It does not postpone the KSeF mandate. From 1 January 2027, the remaining transition periods end and businesses in scope must use the system.
This follows earlier KSeF updates, including our article on what KSeF means for companies operating in Poland and our previous update on KSeF penalties, preparation and next steps.
What has been announced?
The current deferral of penalties for errors in using KSeF runs until the end of 2026. The Polish Ministry of Finance intends to extend it by one year, until 31 December 2027, and has said it will begin work on the necessary legislation.
The proposal is particularly relevant to smaller businesses whose transitional arrangements end on 31 December 2026. If adopted, it would give them more time to become familiar with KSeF and improve their processes after the system becomes mandatory for them.
Other businesses using KSeF could also use that period to identify recurring errors and strengthen their controls. Until the legislative change is adopted, however, the additional year should be treated as a proposal.
The mandate remains in place
The proposed penalty deferral concerns errors made while using KSeF. It is not a delay of mandatory e-invoicing, nor should businesses interpret it as permission to issue invoices outside KSeF where the system is required.
The Ministry says the tax administration will continue to respond to cases of invoicing outside KSeF, subject to the applicable legal exceptions. Poland’s wider focus on structured invoicing and tax control also remains unchanged. We explored that context in our article on Poland’s KSeF mandate and VAT revenues in 2027.
Companies should therefore continue preparing their invoice flows, data quality, ERP integrations and exception handling according to their applicable deadlines.
Why this matters for companies
KSeF affects how invoices are created, submitted, validated and corrected. A technical connection to the platform is only one part of readiness. Finance and tax teams also need accurate data and a clear process for dealing with invoices that fail validation or require follow-up.
These issues can still disrupt operations even if the proposed penalty extension becomes law. Incorrect or rejected invoices may delay billing, create manual work and complicate communication with customers or suppliers.
For companies with high invoice volumes, shared service centres or multiple ERP environments, the priority is to test the full process. That includes what happens when an invoice cannot be submitted, when its status needs checking and when a correction is required.
What companies should do now
Businesses operating in Poland should continue their KSeF implementation as planned. Finance, tax and IT teams should check where invoice data is validated, who monitors submission results and who resolves exceptions.
They should also follow the legislative process. The Ministry has announced its intention to extend the penalty deferral, but the change is not yet in force.
Changes companies need to implement
- Review invoice and master data quality before submission to KSeF.
- Test ERP and e-invoicing integrations across the entities and invoice types in scope.
- Define clear processes for rejected, delayed and corrected invoices.
- Assign ownership for monitoring submission results and resolving errors.
- Train users on how KSeF affects invoice creation, validation and follow-up.
- Monitor the proposed legislative change before updating compliance assumptions.
Key takeaways
- Poland plans to extend the KSeF penalty deferral for usage errors until 31 December 2027.
- The proposed extension requires a legislative change and is not yet in force.
- The KSeF mandate itself has not been postponed.
- The remaining transition periods end on 31 December 2026 for businesses in scope.
- Companies should continue testing invoice flows and improving data quality and exception handling.
For companies managing e-invoicing obligations across multiple countries, Poland shows why mandate readiness depends on reliable invoice data, connected systems and clear process ownership across finance, tax and IT.
Platforms such as Routty help organisations manage structured e-invoicing, validation and compliance processes across different mandate models.
