2 min
How to Handle Non-Polish Invoices in KSeF: A Guide for Businesses
Polish National e-Invoicing System (pl. Krajowy System eFaktur, KSeF), as the name suggests, was primarily designed for domestic transactions. But as the 2026 deadline for mandatory e-invoicing approaches, many businesses are asking: How does KSeF handle foreign invoices? What are the rules when working with international partners? And what should you keep in mind to stay compliant? This article will guide you through the essentials.
Table of contents
- General Rules: KSeF and Non-Polish Invoices
- Receiving Foreign Invoices in KSeF
- Issuing VAT Invoices to Foreign Clients
- Invoicing in Foreign Currencies via KSeF
- Smarter Handling of Foreign Invoices
General Rules: KSeF and Non-Polish Invoices
KSeF is mandatory for all businesses paying taxes in Poland. If your company is registered in Poland and has a Polish tax ID (NIP), you’re considered a Polish taxpayer—even if your headquarters are abroad. That means you’re required to use KSeF, just like any other domestic business.
Receiving Foreign Invoices in KSeF
The process of receiving invoices from a foreign contractor with a Polish NIP is straightforward. You handle it just like any other structured invoice (e-invoice).
However, if the contractor doesn’t operate in Poland and doesn’t have a Polish NIP, you’re not required to report the invoice in KSeF. You can still receive it via traditional methods—paper or PDF—and process it using standard accounting procedures (currency conversion, VAT deduction, etc.), outside of KSeF.
Issuing VAT Invoices to Foreign Clients
If your foreign client has a Polish VAT number, you issue the invoice through KSeF.
In all other cases, you can skip KSeF and send the invoice using your usual method—email, post, or any format agreed upon with the client.
Invoicing in Foreign Currencies via KSeF
Need to issue an invoice in a currency other than PLN? No problem. KSeF supports foreign currencies—just make sure the invoice amount is expressed only in that currency. Use the “KodWaluty” field to specify which one. Currency conversion to PLN follows the same rules as before.
Accurate mapping of XML invoice fields is key to a successful KSeF implementation. It’s not just about compliance—it’s about unlocking the full potential of your financial data in reporting, control, and decision-making processes.
At GoNextStage, we created the KSeF Connector to integrate KSeF with your document workflow and ERP systems. Together with our clients, we analyze every field in the XML structure. Each element is mapped in a dedicated tool, allowing businesses to highlight the fields they use—mandatory and optional alike.
This ensures full compliance with the FA(3) schema, prevents data loss, and enables extended data sharing across internal systems. The result? Better automation, smoother reporting, and more reliable financial insights.
Stanisław Korwin-Kossakowski, Solution Architect GoNextStage
Smarter Handling of Foreign Invoices
KSeF isn’t just a legal requirement—it’s an opportunity to streamline your accounting processes. Instead of manually uploading invoices and posting them separately, imagine a system that automatically pulls data from KSeF into your workflow.
Already using WEBCON BPS or Microsoft PowerPlatform? GoNextStage KSeF Connector lets you keep working in your familiar environment. It fetches invoices directly from KSeF, eliminates double data entry, and supports compliant invoice delivery to foreign clients.
And if you’re just starting to optimize your accounting processes—now’s the perfect time. GoNextStage helps companies analyze, implement, and improve data flows. With the KSeF Connector, you get compliance and real business value. Trusted brands like Canal+, Harden Construction, and G-City have already chosen GoNextStage to streamline their financial operations—proof that smart automation delivers results.
