The introduction of the mandatory National e-Invoicing System (KSeF) will significantly change not only the way invoices are issued, but also how they are delivered and received. As of 1 February 2026, KSeF will become the primary channel for invoice delivery between VAT taxpayers in Poland.

Obligation to Receive Invoices via KSeF

From 1 February 2026, the general rule will be that structured invoices, including invoices issued under the offline24 mode, are delivered to the buyer via KSeF. Importantly, the obligation to receive invoices through KSeF will apply to all taxpayers holding a Polish VAT identification number (NIP), including those who remain temporarily exempt from the obligation to issue invoices in KSeF until the end of March 2026.

This means that:

• if the seller is required to issue invoices via KSeF, and
• the buyer is a Polish VAT taxpayer identified with a NIP,

the invoice must be delivered through KSeF, even if the buyer is not yet required to issue invoices via the system themselves.

Until 31 January 2026, the situation is different — the buyer may decide in which form they wish to receive invoices, and the seller cannot deliver an invoice via KSeF without the buyer’s consent. This model will cease to apply once the mandatory KSeF regime comes into force.

Exceptions to the Obligation to Deliver Invoices via KSeF

The VAT Act (Article 106gb) provides for exceptions under which invoices will not be delivered through KSeF, despite the system being mandatory. These exceptions apply in particular where:

1. the place of supply is located in another EU Member State or in a third country,
2. the buyer does not have a registered office or a fixed establishment in Poland,
3. the buyer has a fixed establishment in Poland, but that establishment is not involved in the transaction,
4. the buyer is a taxpayer from another EU Member State applying the SME VAT exemption scheme,
5. the buyer does not use a VAT identification number or tax identification number,
6. the buyer is a private individual not conducting business activity.

In such cases, the invoice will be made available to the buyer in another agreed form, most commonly as a readable PDF visualization.

Invoice Receipt Date and Tax Consequences

A structured invoice will be deemed received on the date the KSeF reference number is assigned. This date is decisive for, among other things:

• the right to deduct VAT, and
• the recognition of tax-deductible costs.

Where, however, the seller is required by law to make the invoice available to the buyer outside of KSeF, the date of receipt will be the actual date on which the buyer receives the document.

Additional Copy of the Invoice Outside KSeF

Even though an invoice is formally delivered via KSeF, the seller may, but is not required to, provide the buyer with an additional copy or visualization of the invoice (e.g. a PDF) outside the system. This depends solely on the seller’s discretion and is not a statutory obligation.

“Traditional” Invoices and the Right to Deduct VAT

The introduction of mandatory KSeF has not been linked to a prohibition on deducting VAT based on invoices issued in breach of the obligation to use KSeF. The regulations also do not provide for sanctions against taxpayers who:

• deduct VAT, or
• recognize tax-deductible costs

based on “traditional” paper or electronic invoices that were issued incorrectly outside the KSeF system.

This position has been confirmed by the Director of the National Tax Information in an individual tax ruling dated 12 August 2025 (ref. no. 0114-KDIP1-3.4012.507.2025.1.JG).

Summary

Mandatory KSeF represents not only a change in the form of invoices, but a fundamental shift in the logic of invoice delivery and the timing of tax consequences. For taxpayers, this means the need to:

• prepare systems for invoice receipt,
• revise internal procedures,
• closely monitor the moment when a KSeF reference number is assigned.

The earlier companies adapt their processes, the lower the operational and tax risk they will face in 2026.