What the rule checks, the affected field, an example correction and how to validate again.
Affected field
seller.email
Business term
BT-43
Reviewed
10 Oct 2026
Cause and affected field
Use one @, no spaces, and at least two characters on each side of @. A dot should not touch @ or start or end the address. This syntax check does not verify delivery.
Rule family: XRechnung 3.0.2. The finding from the ruleset actually executed remains authoritative.
Correction and example
Fails · schematic excerpt
billing @example.com
Passes · replace with your details
billing@example.com
Validate again
Correct the original in your invoicing system and inspect the replacement file. Ask the supplier to correct an incoming invoice.
Technical validity does not confirm acceptance by the recipient’s portal.
