Some Purchase Invoices May Still Be Received Outside KSeF

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The mandatory National e-Invoicing System (KSeF) significantly changes the way transactions between VAT taxpayers are documented. However, for many entrepreneurs, the crucial question is not how to issue invoices, but how to receive purchase invoices after 1 April 2026.

Will every invoice need to be downloaded exclusively from the system? The answer is more nuanced.

Receiving an Invoice – A New Definition Under KSeF

With the implementation of mandatory KSeF, the very concept of “receiving an invoice” changes.

A structured invoice is deemed delivered once the system assigns it a unique identification number. This means that:

• the moment of receipt does not depend on whether the buyer has actually reviewed the document,

• the right to deduct input VAT is directly linked to the invoice’s presence in the central database,

• traditional delivery channels (paper copies, email, PDF attachments) no longer constitute official invoice transmission in B2B transactions covered by KSeF.

For businesses and accounting departments, this requires a significant operational shift and ongoing system monitoring.

Must All Purchase Invoices Be Received via KSeF?

No.

The obligation applies only to invoices that, under applicable regulations, must be issued as structured invoices.

The VAT Act provides several exceptions, including situations where:

• the seller is not subject to the obligation to use KSeF,

• a simplified invoice is issued,

• the invoice is issued by a foreign entity without a registered seat or fixed establishment in Poland,

• a specific transaction is excluded from the KSeF obligation under special provisions.

In such cases, invoices may still be issued in paper or electronic form outside the system and remain legally valid.

This means that:

• such documents may serve as a basis for recognizing expenses in accounting records,

• they may allow VAT deduction (provided all statutory conditions are met),

• the buyer is not required to upload or introduce these invoices into KSeF.

  
  

If an Invoice Is Issued in KSeF – Only That Version Has Legal Effect

If a seller is obliged to issue a structured invoice and does so in KSeF, the only invoice producing tax effects is the one made available in the system.

Any visual representation (PDF, printout, email attachment) serves solely an informational purpose. It does not replace the structured invoice and cannot serve as an independent basis for settlements.

For tax purposes, only the invoice available within KSeF is binding.

A Hybrid Operational Model After 1 April 2026

In practice, businesses must prepare to operate in a hybrid environment:

1. Continuous KSeF monitoring – receiving structured invoices will become a routine obligation.

2. Handling invoices outside KSeF – paper and electronic invoices will still circulate in transactions with entities not covered by the system.

3. Verification of counterparties’ status – determining whether an invoice should have been issued via KSeF becomes essential.

For management boards and decision-makers, this entails:

• adapting internal procedures,

• updating document workflow policies,

• training accounting and finance teams,

• integrating ERP systems with KSeF.

  
  

Conclusion

The obligation to receive purchase invoices via KSeF applies only to invoices that should legally be issued as structured invoices.

In other cases, paper or electronic invoices issued outside the system remain valid and may be settled under the general VAT rules.

The key issue is no longer merely where the invoice is received, but whether it should have been issued through KSeF in the first place.