Launch of Poland’s National e-Invoicing System

Invoices issued and stored in KSeF are uploaded to a central database maintained by the Ministry of Finance, enabling tax authorities to view documents almost in real time. KSeF will gradually become mandatory for nearly all entities issuing invoices in Poland, starting from 01 February 2026.

General information

KSeF forces businesses to issue invoices exclusively in electronic form, using a standardised XML format. Once issued, invoices are validated and assigned a unique identification number. According to the Ministry of Finance, this solution will simplify the invoicing process and reduce risks associated with invoicing errors.

At the same time, the transition presents certain challenges. From a technical standpoint, accounting systems will need to be updated to integrate with KSeF. If such integration is not feasible, businesses will either have to switch to a different system or use a free invoicing tool that the Ministry plans to release in November 2025.

Who will be required to use KSeF?

The obligation to use KSeF will be introduced in stages:

• Effective 01 February 2026: Businesses whose sales in 2024 exceeded PLN 200 million (including VAT).
• Effective 01 April 2026: All remaining businesses.

It should be noted that, in general, foreign entities are not required to use KSeF and can continue issuing invoices in paper or electronic form outside the new system. They may also use KSeF and enjoy its benefits, provided they have a Polish tax identification number (NIP).

On the other hand, Polish contractors are required to issue invoices to their foreign counterparts via KSeF. Since foreign businesses do not face the same obligations, Polish contractors must also provide them with invoices in paper or electronic form outside of KSeF.

Practical impact 

The introduction of KSeF will have far-reaching consequences for Polish businesses and their foreign counterparts. The most significant changes include:

• A substantial limitation on the ability to issue paper invoices for Polish companies; 
• Near-instant delivery of invoices to recipients once issued;
• Simplified document retention. Invoices issued via KSeF will be archived electronically for 10 years;
• Faster VAT refunds. Taxpayers using KSeF will be eligible for VAT refunds within 40 instead of 60 days; and 
• Faster invoicing – KSeF makes it possible to import invoice data from customers and suppliers directly into the company’s accounting system.

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Piotr Prokocki specialises in comprehensive services for M&A, and develops effective structures for financing transactions, capital withdrawal, and profit distribution. 

Konrad Gańczarczyk has experience in ongoing tax advisory services to companies operating in the real estate, construction, and IT sectors.