# BR-DE-7

Source: https://xmlvalid.com/rules/BR-DE-7

> Das Element "Seller contact email address" (BT-43) muss übermittelt werden.

- Level: error
- Rule sets: XRechnung 3.0 rules (UBL) 2.6.0
- Context: `/ubl:Invoice/cac:AccountingSupplierParty/cac:Party/cac:Contact | /cn:CreditNote/cac:AccountingSupplierParty/cac:Party/cac:Contact`
- Test: `cbc:ElectronicMail[boolean(normalize-space(.))]`

> Das Element "Seller contact email address" (BT-43) muss übermittelt werden.

- Level: error
- Rule sets: XRechnung 3.0 rules (CII) 2.6.0
- Context: `/rsm:CrossIndustryInvoice/rsm:SupplyChainTradeTransaction/ram:ApplicableHeaderTradeAgreement/ram:SellerTradeParty/ram:DefinedTradeContact`
- Test: `ram:EmailURIUniversalCommunication/ram:URIID[boolean(normalize-space(.))]`

## Why it fails

- The seller contact has no email address: `cac:Contact/cbc:ElectronicMail` (`ram:EmailURIUniversalCommunication/ram:URIID` in CII) is missing or empty.

## How to fix it

- Add an email address to the seller contact, one that someone reads: German public buyers use it for questions about the invoice.

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