Polish-based companies have issued business invoices through KSeF, the national e-invoicing system, since 1 February 2026 if their 2024 sales topped PLN 200 million, otherwise since 1 April 2026. For a company based abroad, a Polish VAT number decides nothing by itself. Under Article 106ga(2) of the VAT Act, as the Ministry of Finance explained on 28 January 2026, the duty applies only where a fixed establishment in Poland takes part in the invoiced supply, judged case by case.
Where a foreign company stands
| Situation | What it means |
|---|---|
| No seat or fixed establishment in Poland | KSeF is voluntary, decided invoice by invoice |
| A fixed establishment that takes part in the sale | KSeF is mandatory |
| A fixed establishment taking no part, such as a marketing-only branch | KSeF is voluntary |
| Buying from a Polish supplier under your Polish NIP | unless you state that no establishment of yours takes part, the supplier may leave the invoice in KSeF only |
Purchase invoices live in KSeF
An invoice counts as received once KSeF assigns its number, and a company named by its NIP sees its purchase invoices after logging in. Without a qualified e-seal, a foreign company files a ZAW-FA notification naming one person, who then grants further permissions inside KSeF. An invoice's visual copy may be in English if it matches the XML sent to KSeF.
For an ERP built outside Poland that means pulling purchase invoices on a schedule and, where the duty applies, sending sales invoices as FA(3). Our integration pulls purchase invoices incrementally at the Ministry's recommended intervals, and we work remotely, with calls and contracts in English.
Our KSeF integration page covers stores, billing systems and ERPs, and Software house in Poland explains how we work with foreign clients.
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