Idempotency
How should idempotency be implemented for e-invoice submission?
Short answer
Use an idempotency key linked to the invoice, XML version and submission attempt. If the same request is repeated after a timeout or retry, the system should recognise it and avoid creating a second submission. Idempotency is an operational safeguard against duplicates.
Key
Unique key
Bind it to the document and the XML version.
Retros
No duplication
A repeated request should not create a second submission.
A change
New XML
Changed content needs a new record and reason.
Audit
The result of the attempt
Save whether it was a new or repeated request.
Conclusion
Idempotency is an essential practical safeguard for e-invoice API submission; it prevents an uncertain retry from becoming a duplicate delivery.
Sources
- Law no. 431/2002 Z. z. Coll. about accounting
- Law no. 222/2004 Z. z. Coll. about VAT
- Internal rules of document integrity
the VAT Act · current FAQ of the Financial Administration of the Slovak Republic on e-invoice · Peppol BIS Billing 3.0
Not legal advice.