KSeF: mandatory e-invoicing from 2026 | Kancelaria Prawna i Doradztwa Prawnego

Business law

KSeF: mandatory e-invoicing from 2026

The mandatory KSeF timetable and organisational points to check.

What has changed

The Act of 5 August 2025 introduced mandatory issuing of structured invoices through the National e-Invoice System (KSeF). These rules replace voluntary use of the system for transactions covered by the obligation.

From when

From 1 February 2026, the obligation applies to taxpayers whose VAT-inclusive sales exceeded PLN 200 million in 2024. For other taxpayers, the main date is 1 April 2026; certain obligations for the smallest entities are deferred until 1 January 2027.

Who is affected

The scope depends on the taxpayer's status, the invoice type and transitional rules. A counterparty's use of KSeF does not by itself determine the other party's obligation.

What to prepare

Consider identifying authorised users, the flow of data between accounting and sales, and procedures for system outages. It is also worth checking whether the accounting system supports the current invoice logical structure.

Source and notice

The primary source is the Act of 5 August 2025 amending the VAT Act and certain other acts, Journal of Laws 2025 item 1079. This is general information; applying the rules requires an assessment of the specific facts.

This material is for general information only; it is not legal advice and does not promise an outcome.

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