On January 1, 2026, the Ministry of Finance made the invoice submission module with attachment functionality available through the e-Tax Office, allowing taxpayers to register their intention to issue invoices with attachments in KSeF 2.0.
Process for the issuance of Invoices with Attachments
To issue invoices with attachments in KSeF 2.0, taxpayers must first submit a notification through the e-Tax Office service. The Ministry has provided a form requiring the following information:
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Taxpayer details and email address
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Type of activities to be documented with invoice attachments (e.g., electricity supply, telecommunications services, fuel supply)
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Expected technical parameters, including average monthly invoice volume and average invoice size in kilobytes
Notifications may be submitted by natural persons holding a NIP (National Tax Identification Number) on their own behalf, or by authorized users of an organization’s account (UKO) acting on behalf of non-natural persons such as companies.
Applications are processed in order of receipt, with a maximum turnaround time of three business days. Taxpayers will receive confirmation at the email address provided in the notification, after which they may begin issuing invoices with attachments.
Discontinuing the Attachment Functionality
Taxpayers wishing to discontinue issuing invoices with attachments must submit a separate notification through the e-Tax Office. Upon completion, the attachment functionality will be removed while the taxpayer retains the ability to issue standard invoices in KSeF 2.0.
Attachment’s Requirements and Restrictions
The Ministry has clarified that attachments are an integral part of the invoice XML file. KSeF 2.0 will not accept unstructured attachments separate from the invoice file.
Attachments are strictly limited to tax-related information or data closely connected to such information. The following are expressly prohibited:
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Marketing information
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Contracts
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Receipt protocols
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Price lists
A violation of these rules may result in revocation of the right to issue invoices with attachments.
Taxpayer Support
The Ministry has made support available through the KSeF notification form at ksef.podatki.gov.pl/form.
For future updates on Poland and similar developments in other countries, follow our Regulatory Analysis page.
