What is e-invoice?
Short answer
e-invoice is a structured electronic invoice in XML format based on the European standard EN 16931 and, in Slovak practice, Peppol BIS Billing 3.0. The receiving system can automatically read, validate and process its data without manual re-entry or OCR. A PDF or image sent by email is not an e-invoice merely because it is an electronic file; machine-processable structured data is decisive. The Slovak framework is set out in § 76a and § 85o of Act No. 222/2004 Z. z. on VAT. The mandatory B2B and B2G regime starts on 1 January 2027, while 2026 is a voluntary testing period.
XML as a core
A structured document according to the agreed standard, not just a visual form of the invoice.
Automation
The system can load individual fields without rewriting or OCR.
Check the rules
The document must pass both technical (XSD) and content validation (business rules EN 16931/Peppol).
Certified channel
Sharp delivery goes through a certified delivery service — a e-invoicing delivery-service provider.
Conclusion
e-invoice is a data document that should be processable, validable and traceable.
Sources
- Law no. 222/2004 Z. z. Coll. on VAT, § 76a
- Law no. 222/2004 Z. z. Coll. on VAT, § 85o
- EN 16931 and Peppol BIS Billing 3.0
Not legal advice.