Official FS FAQ · attachments

What is the maximum size of an e-invoice attachment?

⚠ Machine-translated answer, not yet manually reviewed. For the exact wording, see the Slovak original.

Short answer

There is no single universal limit that applies to every delivery-service provider. The Slovak Financial Administration states that providers may set their own technical limits; in practice, a limit of approximately 100 MB is often used. Confirm the actual limit with the selected provider before implementation or submission.

Detailed explanation

For large attachments, it is therefore not enough to check the XML alone. You need to verify the limit of the specific digital mail service, the type of attachment, the size of the message after compression, and whether the attachment belongs in the invoice at all or should be handled via a separate sales channel.

As stated in an official source

This is technical and operational information from the Financial Administration’s official FAQ. The specific limit may be set out in the provider’s contractual or technical terms and conditions.

Source

This does not constitute legal advice. Primary sources: FAQ Financial Administration of the Slovak Republic k e-invoice; portal of the Financial Administration of the Slovak Republic to e-invoice. Further sources: Financial Administration of the Slovak Republic, FAQ 9/DPH/2025/IM on e-invoices, version 7 July 2026, Example No. 67. Verified 8 July 2026.

Official cases from the Slovak Financial Administration’s FAQs

The following questions and answers are taken from the current July FAQ from the Financial Administration and have been assigned to this topic. Grouping the cases prevents the creation of duplicate pages, whilst retaining the full answer and the exact wording of the question.

Example No. 67: What is the maximum size of an e-invoice attachment?

The Peppol specifications do not explicitly define a uniform global hard limit on message size, whilst individual delivery service providers (DSPs) may have their own technical limits defined. In practice, a limit of approximately 100 MB is often used.

Primary source: Financial Administration of the Slovak Republic, FAQ 9/VAT/2025/IM k e-invoice, July 2026 update. Processed and checked on 13 July 2026.