How should e-invoice XML be tested before production deployment?
Short answer
Before deploying a new or modified e-invoice generator, validate its XML with the official Peppol Testbed validator at testbed.peppol.org/validation. The validator checks the UBL 2.1 structure and the business rules defined by EN 16931 and Peppol BIS Billing 3.0.
Official validator
A free pre-production XML inspection tool.
Formal structure
Checking the basic correctness of the XML document.
Business rules
Check compliance with EN 16931 and Peppol BIS Billing 3.0.
Before the change in production
Testing after ERP update or XML generator change.
Detailed explanation
Such testing should be incorporated as a standard step whenever there is a major change to the invoicing or accounting system — for example, when updating an ERP version, changing the method of XML generation, or introducing new document types such as credit notes or debit notes. Before the modified system is connected to the live, production digital mailbox and begins sending actual invoices to business partners, testing against the validator helps to identify errors in a secure environment without risking actual business relationships.
As set out in the Act
The existence and availability of the official validator stem from the technical infrastructure of the Peppol network, managed by OpenPeppol. The obligation to comply with the electronic invoice format in accordance with the European standard is set out in Section 85o of Act No. 222/2004 Coll. on VAT.
Practical examples
- After modifying the XML template, the developer will verify the new output via the validator at testbed.peppol.org before deploying it into production.
- After migrating to the new version of the ERP system, the company will test several sample invoices before sending them to actual business partners.
- Any errors detected by the validator will be corrected in the test environment without the risk of them reaching a business partner.
Most common mistakes
- “Pre-production XML testing is not necessary; it is sufficient to rely on the e-invoicing delivery-service provider’s checks.” Verification in advance helps to catch errors before they reach actual communications with partners.
- “The Peppol Testbed validator only checks the formal XML schema, not the business rules.” The tool also verifies business (Schematron) rules in accordance with EN 16931 and Peppol BIS Billing 3.0, not just the UBL structure.
- “Testing only needs to be carried out once, during the initial deployment of the system.” It is recommended to repeat the process whenever there is a major change to the invoicing or accounting system.
Conclusion
Validate representative XML documents in Peppol Testbed before production so that both the formal schema and business rules are checked.
Legal basis
- Technical infrastructure of the Peppol network (OpenPeppol), validator testbed.peppol.org
- Act No. 222/2004 Coll. on VAT, Section 85o
Related questions
This is not legal advice. Sources: Act No. 222/2004 Coll. on VAT, EN 16931 and Peppol BIS Billing 3.0 (OpenPeppol documentation, docs.peppol.eu), official methodological and information materials from the Slovak Financial Administration on e-invoices. Verified on 7 July 2026.