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E-Invoice Validator

DE-R-028

warningUBL

Official rules text

"Seller contact email address" (BT-43) should contain exactly one @-sign, which should not be framed by a whitespace or a dot but by at least two characters on each side. A dot should not be the first or last character.

Rules and regulations

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  • Official EN 16931 regulations
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Official rule sets up to date: EN 16931 1.3.17 · Peppol BIS 3.0.20 · XRechnung 3.0.2 (KoSIT 2.6.0). Last checked against the sources on 12.10.2026.