Government proposes further changes to KSeF, a legislative proposal is ready

Michał Wykurz

The Finance Ministry has published a proposal to amend the VAT Act to introduce many important changes to the National E-Invoicing System (KSeF). The most prominent among these is an option to issue invoices offline without having to be permanently connected to KSeF.

Offline KSeF – what’s it about?

It is proposed that businesses be allowed to issue electronic invoices even without having a direct access to KSeF, e.g. due to system failure, lost internet connection or technical issues. In such cases an invoice will be issued locally and will have to be submitted to KSeF on the next business day at the latest.

Important points:

• Offline mode is supposed to be a permanent feature rather than merely an emergency option.
• Use of the feature will require a new invoice issuer certificate that will have to be downloaded and duly registered.

Invoices with attachments but not for everybody

Another change is to allow businesses to submit invoices with attachments. While the functionality will be available technically, not everyone will be permitted to use it straight away.

To submit your invoice with an attachment (e.g. contract scan, technical specs, certificate of acceptance) you will have to first notify such a need to e-Tax Office. In response, the system is supposed to confer an individual authorisation enabling you to use the option.

Changes are for the better, but time running short

Experts are in agreement that the proposed changes do address real needs of business. The offline mode and the attachments functionality are long-awaited facilities that make KSeF more flexible and usable.

On the other hand, the introduction of KSeF as a mandatory system is approaching fast (1 February 2026 is the new deadline for most taxpayers) and any legislative amendments trigger the need for process updates, system integration and new tests.

Summary

The projected KSeF changes are a step towards a greater flexibility of the system that will make it better suited for operation in the realities of everyday business. The offline mode and the invoice attachment functionality are important options that can greatly increase e-invoicing comfort.

At the same time, as is always the case with system changes, appropriate organisational and technological preparation will be of key importance. You are advised to monitor the development of this legislation and not to wait with planning for implementation.