Regional spotlight

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Overview of B2G, B2B and B2C e-invoicing in Poland.
Key formats, networks and channels you may need to support.
High-level regulatory and compliance considerations.

e-invoicing in Poland

Poland uses KSeF (Krajowy System e-Faktur), the national e-invoicing system, as the centralised platform for all invoice traffic. Both domestic and cross-border invoices are reported to KSeF using the FA(3) structured invoice format defined by the Polish tax authority. For domestic B2B transactions, KSeF is the sole delivery channel — invoices are issued through KSeF, and KSeF handles delivery to the recipient. For cross-border invoicing, invoices are reported to KSeF and additionally sent via the Peppol network when full Peppol address details are provided.

Poland is currently supported only for selected partners. Please contact Maventa Support for more information on how to set this up with your ERP for Polish companies.

Polish company account registration

When registering a new Polish company via the API, the Polish VAT number must be used as the company identifier. At the moment, company registration requires the vendor to have KYC approval from Maventa. Contact Maventa support to get started.

Identifier	Description	Format	Validation
VAT number	Polish VAT identifier (NIP)	`PL1234567890`	Structural validation via VIES

Sending in Poland

KSeF reporting and delivery

All invoices sent through Maventa for Polish companies are reported to KSeF. When Maventa sends an invoice to KSeF, the invoice is converted to the FA(3) format — the official KSeF structured invoice schema, mandatory from 1 February 2026. For each successfully submitted invoice, KSeF returns a UPO confirmation and the sender can download both the UPO and the cleared FA(3) document via the API.

Domestic invoices are routed exclusively to KSeF by Maventa — the sender does not need to take any additional steps. KSeF acts as the delivery platform and handles forwarding the invoice to the recipient. No other delivery channel is used for domestic traffic.

Cross-border invoices are reported to KSeF and additionally sent via the Peppol network — but only when the full Peppol address details are provided in the sending API metadata. This means both the recipient’s Peppol endpoint ID and the operator’s Peppol identifier must be explicitly included.

If the full Peppol address details are not provided for a cross-border invoice, the invoice is reported to KSeF but is not delivered to the recipient via Peppol or any other channel. The invoice status shows as SENT because KSeF accepted it, even though the invoice has not actually reached the recipient. Maventa does not automatically reroute these invoices — the sender must manually reroute the invoice to email or print if these delivery channels are enabled for the sender account.

Email and print delivery

Email and postal delivery (printing) are available as additional delivery channels but are not applied automatically by Maventa. If an invoice needs to be delivered via email or print — for example when Peppol delivery was not possible or no Peppol address was provided — the sender must reroute the invoice to these channels manually. Printing is handled in Finland, and all postal deliveries are sent from Finland.

UPO — official confirmation of receipt

For every invoice successfully submitted to KSeF, Maventa receives a UPO file (Urzędowe Poświadczenie Odbioru — Official Confirmation of Receipt). The UPO is issued by the Polish tax authority system and serves as formal proof that the invoice was received and registered by KSeF.

The UPO typically contains:

Submission reference and request ID
KSeF ID (the unique invoice number assigned by KSeF)
Date and time of receipt
Processing status (accepted or rejected)
Sender details
Hash and integrity reference

The KSeF ID is also available via GET /v1/invoices/{id}/actions in the field channel_details.external_number.

Downloading the UPO and cleared document

Both the UPO file and the CLEARED_DOCUMENT (the FA(3) file as submitted to KSeF) are listed in the files array of the GET /v1/invoices/{id} response. Each file entry includes an id, filename, type, and mimetype.

File type	Description
`UPO`	Official Confirmation of Receipt from KSeF. Available only for sent invoices.
`CLEARED_DOCUMENT`	The FA(3) invoice file as registered with KSeF. Can be downloaded for bookkeeping or legal compliance purposes.

To download a file, use GET /v1/invoices/{id}/files/{file_id} with the id from the file entry.

Why is the UPO important?

The UPO serves as legal evidence that the invoice was delivered to the official KSeF platform. It provides an audit trail for compliance, dispute resolution, and customer support. The UPO can be stored in ERP or invoice management systems as the official delivery confirmation for Polish invoices.

Archiving is the partner’s responsibility. Polish invoices must be archived for 10 years.

Receiving in Poland

For domestic traffic, invoices sent by other Polish companies arrive via KSeF. Maventa retrieves these invoices from KSeF and delivers them to the recipient’s Maventa account, where they can be downloaded. For international traffic, invoices can be received via the Peppol network or directly from other Maventa customers — this requires Peppol SMP registration (see below).

Received cross-border invoices are not currently reported to KSeF. KSeF is primarily the structured invoice system for invoices issued by entities in scope — especially domestic Polish transactions. Invoices from foreign suppliers typically remain outside KSeF unless the supplier has a Polish fixed establishment participating in the supply or voluntarily uses KSeF.

Address Type	Description	Example address	Activation Requirement
Peppol address	Official identifier for the Peppol network. Uses the VAT number with scheme `9945`.	9945:xxxxxxxxxxx	Created when the company registers to receive from Peppol

Peppol SMP registration

To receive invoices via Peppol, a Polish company must first be registered in the SMP (Service Metadata Publisher). The SMP registration determines which document formats the company can receive over the Peppol network.

Maventa does not yet support Peppol SMP registration for Polish companies. This capability is expected to become available within the coming weeks.

When registration becomes available, the following document types are registered in the SMP:

Peppol BIS Billing 3.0 — Invoice

DocumentIdentifier urn:oasis:names:specification:ubl:schema:xsd:Invoice-2::Invoice##urn:cen.eu:en16931:2017#compliant#urn:fdc:peppol.eu:2017:poacc:billing:3.0::2.1

ProcessIdentifier urn:fdc:peppol.eu:2017:poacc:billing:01:1.0

Peppol BIS Billing 3.0 — Credit Note

DocumentIdentifier urn:oasis:names:specification:ubl:schema:xsd:CreditNote-2::CreditNote##urn:cen.eu:en16931:2017#compliant#urn:fdc:peppol.eu:2017:poacc:billing:3.0::2.1

ProcessIdentifier urn:fdc:peppol.eu:2017:poacc:billing:01:1.0

Scanning

Scanning is available in Poland via the AutoScan solution.

For step-by-step instructions on enabling receiving, registering for Peppol, and setting up scanning, see the invoice receiving integration guide.

e-invoicing formats used in Poland

ERP integrations for Polish companies should use Peppol BIS Billing 3.0 for both sending and receiving. This is currently the only format with a guaranteed working conversion to and from the Polish FA(3) format used by KSeF.

Format	Standard	Notes
FA(3)	Polish national standard	Official KSeF structured invoice schema defined by the Polish tax authority, mandatory from 1 February 2026. All invoices sent to KSeF are converted to this format.
Peppol BIS Billing 3.0	EN16931	Recommended format for ERP integrations. Used for cross-border Peppol delivery alongside KSeF reporting.

Maventa also supports Polish-localised PDF for both sent and received invoices.