State of EU e-invoice errors 2026
Which validation rules do real Peppol BIS 3.0 and e-SLOG 2.0 invoices actually fail? This report aggregates every validation observed by einvoicecheck into per-rule failure counts — original data nobody else publishes. The single most-failed rule so far is DE-R-019, which fired in 21.1% of observed validations.
Data window: 19 validations observed by einvoicecheck between 2026-07-19 and 2026-09-04. Counts are per-validation distinct rule failures — one invoice failing a rule twice counts once. Metadata only: no invoice content is stored. Refreshed continuously; page reviewed quarterly.
Most-failed validation rules
| # | Rule | Failures | % of validations |
|---|---|---|---|
| 1 | DE-R-019 | 4 | 21.1% |
| 2 | XSD-001 | 2 | 10.5% |
| 3 | DK-R-002 | 1 | 5.3% |
| 4 | PEPPOL-EN16931-R003 | 1 | 5.3% |
| 5 | UBL-CR-001 | 1 | 5.3% |
Failures by rule family
Failures by format
| Format | Failures | Share |
|---|---|---|
| Peppol BIS Billing 3.0 | 7 | 77.8% |
| unknown | 2 | 22.2% |
Methodology
Every validation run through the API or the free browser validator increments a per-day counter for each distinct rule that failed (plus one for the validation itself). No invoice content, amounts, or party data are stored, and counts are not linked to accounts — the aggregate holds rule IDs and dates only, consistent with our privacy policy. Test-mode API keys are excluded so CI loops don't skew the numbers.
Want to know what a specific rule means? Every rule has a page: browse the catalogue.