`BR-DE-28`

XRechnung (KoSIT) · validation rule

XRechnung (KoSIT)Warning

The seller contact e-mail address (BT-43) is malformed: XRechnung expects exactly one @ with at least two characters on each side, no spaces, and no dot directly before or after the @ or at the start/end. The sender must correct cac:Contact/cbc:ElectronicMail / ram:EmailURIUniversalCommunication/ram:URIID.

Field: seller.contact.email (BT-43)
Rule set: XRechnung (KoSIT)
Rule-set version: XRechnung 3.0.2 Schematron 2.6.0 · in force since 2026-10-17 · Rule-set changelog
Who has to fix it: The sender

This is a property of the file you received, so it cannot be corrected on your side without changing the document — ask the supplier to reissue it.

Check your own invoice

Drop the file that failed. We parse it, run the official rule sets against it and list every finding with a fix — 20 invoices per day, no key, nothing stored.

Open the live demo

Same explanation over the API: GET /v1/rules/BR-DE-28?lang=en