Mandatory from 1 January 2027

Generate and validate e-invoices — as an API

XRechnung (UBL and CII) and ZUGFeRD are formally strict and change continuously. NormAPI owns the formats and the rule maintenance so your software does not have to.

Validate an invoiceBrowse all error codes →
Validation report

Request

$ curl -X POST api.normapi.de/v1/validate \
    -H 'Content-Type: application/xml' \
    --data-binary @invoice.xml

Response

"acceptable": false

BR-CO-16Amount due for payment does not add up
Rule setv2026-01-31

The deadlines

  1. Since 1 January, every company must be able to receive e-invoices.

  2. Companies with more than €800,000 prior-year turnover must issue e-invoices.

  3. The obligation extends to every company.

Transition rules and exemptions in the guide →

What NormAPI does

Generate

Send invoice data as JSON, receive a valid XRechnung (UBL or CII) or ZUGFeRD document.

Validate

Upload a file and get a readable list of what is wrong — not just Schematron codes.

Rulesets

Rule sets are versioned. Pin a version or track the current one automatically.