How do you check if an e-invoice is valid?

What is checked

Structure. Is the file technically valid XML in the expected format?

Mandatory fields. Invoice number, date, performance period, tax information, details for both parties.

Calculation rules. The standard contains rules that check mathematical consistency: sum of items, tax amounts, total sum.

Specific implementation. XRechnung and other national specifications have additional rules beyond the standard.

When it should be checked

Upon receipt, automatically. An invoice that only becomes apparent as faulty three weeks later causes multiple times the effort – and potentially missed early payment discounts.

Before sending. Equally important: A rejected invoice delays payment.

What a validation does not achieve

It indicates whether the invoice is formally correct – not whether it substantially matches. A wrong amount in the correct field passes every validation.

The substantive check – does it match the order, was it delivered – remains a separate step.

Practical setup

1. Receipt → automatic validation
2. Faulty → immediate feedback to sender
3. Valid → substantive check against order and delivery
4. Approval → booking

Steps 1 and 2 can be fully automated. Exactly this is the benefit of e-invoicing.