KSeF for foreign companies selling to Polish businesses: what changes and who must use it

As of 30 October 2026; the status of the act deferring the penalties is as of 8 November 2026. This is not tax or legal advice. The article describes the Polish VAT Act, EU VAT rules and guidance from Poland’s Ministry of Finance. For your specific situation, speak to a tax adviser who knows Polish VAT.

KSeF (Krajowy System e-Faktur) is Poland’s national e-invoicing system. Since 2026, Polish businesses must issue invoices to other businesses as structured XML files sent through it. Foreign companies that sell to Polish customers or buy from Polish suppliers often ask the same question: does this apply to us? Usually not for issuing. But it does change what you receive.

The timeline in Poland

• 1 February 2026: KSeF became mandatory for issuing invoices for businesses whose 2024 sales including VAT exceeded PLN 200 million. From the same date, Polish businesses receive invoices through KSeF.
• 1 April 2026: mandatory for all other Polish businesses.
• Until 31 December 2026: a business may still issue invoices outside KSeF if the invoices that would have to go through KSeF total no more than PLN 10,000 gross in a month (Article 145m).
• 1 January 2027: the monthly limit ends.

The duty to receive invoices through KSeF does not apply to foreign businesses or consumers. The Ministry of Finance says so in its questions and answers.

Who must issue invoices in KSeF

Article 106ga(1) of the VAT Act requires taxpayers to issue structured invoices through KSeF. Article 106ga(2) lists exceptions. Two matter for foreign companies:

1. No seat and no fixed establishment in Poland: the taxpayer does not have to issue invoices in KSeF.
2. No seat in Poland, but a fixed establishment there that does not take part in the sale: the obligation does not apply to that invoice.

If a foreign company’s fixed establishment in Poland does take part in the sale, the invoice goes through KSeF like any Polish invoice.

The fixed establishment test

“Fixed establishment” is an EU VAT concept. Article 11 of Council Implementing Regulation 282/2011 describes it as an establishment, other than the business’s main seat, with a sufficient degree of permanence and a suitable structure of human and technical resources. The two tests concern receiving services for its own needs and supplying services.

Two points matter in practice:

• A Polish VAT number is not enough. Article 11(3) says that having a VAT identification number does not in itself mean a fixed establishment.
• The Ministry of Finance gives an example: a Slovak company registered for VAT in Poland, with no seat or fixed establishment there, does not have to issue invoices in KSeF.

Whether a warehouse, office or team in Poland is a fixed establishment depends on the facts. This is the question to put to a tax adviser.

Using KSeF voluntarily

A foreign company that is not obliged may still issue structured invoices in KSeF (Article 106ga(4)). To do so, the company needs a Polish tax identification number, access to KSeF and invoicing software that can send files in the required format.

The Ministry of Finance also covers self-billing:

• a foreign buyer with a Polish VAT number that self-bills is not obliged to use KSeF, but may do so voluntarily;
• self-billing by a buyer without a Polish tax number is excluded from KSeF by a regulation of 7 December 2025 (Dz.U. 2025 poz. 1740), and technically cannot be done in KSeF.

Selling to Polish businesses: what your customers see

If you are not obliged and do not use KSeF, you invoice your Polish customer as before, on paper or electronically (Article 106ga(3)). As the Ministry of Finance puts it, KSeF changes the form of invoicing, not the VAT rules themselves, such as the place of supply.

What may change is your customer’s process. Polish companies now receive most supplier invoices in one system and may ask you to use it. You are not obliged to agree. If many of your Polish customers ask, voluntary use is an option to consider.

Buying from Polish suppliers: how invoices reach you

This is where every foreign business feels KSeF. Your Polish supplier must issue its invoice to you in KSeF. Because you are a buyer without a seat or fixed establishment in Poland, the supplier then makes it available to you in a way you agree (Article 106gb(4)), for example as a PDF or printout.

When the invoice is used outside KSeF, it must carry a QR code linking to the invoice in KSeF, so you can check its data (Article 106gb(5)). The Ministry of Finance shows this with a Polish doctor invoicing a Swedish business: the invoice is issued in KSeF and sent to the buyer as a printout or PDF with a QR code.

The date of receipt for you is the date you actually receive the invoice (Article 106na(4)), not the date it gets a KSeF number.

If the supplier issues an invoice in an offline mode, before it has a KSeF number, a PDF for a foreign buyer carries two QR codes, labelled “OFFLINE” and “CERTYFIKAT”. Once the invoice has a KSeF number, one code is enough.

What to agree with Polish suppliers:

• the channel: e-mail address, portal or other;
• the format: PDF with QR code, and the XML file if your system can read it;
• who to contact if an invoice does not arrive.

Penalties

Article 106ni provides for a penalty of up to 100% of the VAT on an invoice issued outside KSeF when it should have been issued in it, or up to 18.7% of the total where the invoice shows no VAT. It applies only to taxpayers who were obliged to use KSeF. Under the current text of the Act it applies from 1 January 2027. On 16 September 2026 the Ministry of Finance announced that the penalties would apply from 1 January 2028. On 20 October 2026 the Council of Ministers adopted the draft act and sent it to the Sejm as print no. 3245, which had its first reading on 21 October 2026. The Sejm passed the act without amendments on 6 November 2026. As of 8 November 2026 it still needs the Senate and the President’s signature and has not been published in the Journal of Laws, so the current text applies until then.

A checklist for foreign companies

1. Confirm with a tax adviser whether you have a fixed establishment in Poland, and whether it takes part in your sales.
2. If you do and it does, plan KSeF invoicing now, before the PLN 10,000 monthly limit ends on 1 January 2027.
3. If you do not, decide whether voluntary KSeF use is worth it for your Polish customers.
4. Tell Polish suppliers how you want to receive invoices: channel and format.
5. Check that your accounts payable team accepts PDFs with a KSeF QR code and knows how to check them.
6. Record the actual date you receive each Polish invoice.
7. If you self-bill Polish suppliers, check whether you have a Polish tax number and what that means for KSeF.
8. Keep an eye on the draft that moves penalties to 2028.

For an overview of how we work with companies in Poland, see our page for Poland.

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