KSeF and foreign invoices - what about imports and exports?

The National e-Invoicing System (KSeF) will come into effect in 2026 and will cover all businesses in Poland. For companies operating solely in the domestic market, process preparation will be relatively straightforward. However, companies involved in international trade need to consider additional issues - especially for invoices issued or received from foreign counterparties.
In this article, we explain how KSeF affects import and export invoices, and what steps a company should take to stay compliant.

Why is it mandatory to integrate with KSeF?

KSeF is the Ministry of Finance's central platform for issuing, transmitting and archiving invoices in a structured electronic format. This allows tax authorities to control and analyze transactions faster, reducing the risk of tax fraud.
Companies that do not integrate their invoicing systems with KSeF will not be able to properly issue and receive compliant invoices. What's more, invoices sent through traditional channels, such as email or paper, without an acknowledgement of receipt by KSeF, will not be considered tax documents. This means that the counterparty will not be obliged to pay them - and your company may have trouble collecting the receivables.

What are the risks of not integrating with KSeF?

1. risk of rejection of invoices by clients and customers
Without KSeF uploading the invoice, the document will not have the status of a valid VAT invoice. Recipients may refuse to accept and settle such a document, which in practice means liquidity problems.
2. possibility of financial penalties
Non-compliance with the KSeF obligation may result in tax audits and penalties for improper accounting records. Sanctions can range from fines to other financial consequences.
3 Problems with VAT deduction and tax settlements
Invoices outside of the KSeF system may be challenged by tax authorities, which could hinder VAT deductions and lead to billing adjustments.
4 Loss of business confidence
Contractors, especially large companies and public institutions, are increasingly demanding compliance with KSeF as a condition for cooperation. Failure to integrate could result in the loss of key customers and partners.

Does an emailed invoice have to be paid?

According to current regulations, an invoice must be issued and received by KSeF to be a tax document. An invoice sent only by email, without the intermediation of the KSeF system, does not meet this requirement. In practice, this means that:

• Email invoices without confirmation of receipt by KSeF are not invoices in the sense of tax law.
• The recipient of an invoice has no legal obligation to pay it if it was issued outside KSeF (unless the parties agree otherwise).
• Such an invoice does not allow for proper accounting for VAT or showing it in the VAT register.

How to prepare your company for integration with KSeF?

Verify your financial and accounting systems for KSeF readiness - check whether your ERP or invoicing software allows integration.

• Use a professional technology partner to ensure fast and secure KSeF implementation and support during the process.
• Train your invoicing and billing staff to minimize the risk of errors and delays.
• Implement a contingency plan for technical problems with KSeF, such as a local document archive and monitoring of invoice statuses.

Failure to integrate with KSeF carries serious financial and operational consequences for any company operating in the Polish market. Only invoices issued and received by the KSeF system will be considered valid tax documents, while invoices sent traditionally, e.g. by email, will not have such status and may not be paid by contractors. To avoid penalties and liquidity problems, it is advisable to implement the appropriate integration solutions as soon as possible and ensure full compliance with the new requirements.