# FX-SCH-A-000159

Source: https://xmlvalid.com/rules/FX-SCH-A-000159

> The Buyer electronic address (BT-49) shall have a Scheme identifier.

- Level: error
- Rule sets: Factur-X BASIC rules 1.09
- Context: `/rsm:CrossIndustryInvoice`
- Test: `normalize-space(rsm:SupplyChainTradeTransaction/ram:ApplicableHeaderTradeAgreement/ram:BuyerTradeParty/ram:URIUniversalCommunication[1]/ram:URIID/@schemeID) != '' or not (rsm:SupplyChainTradeTransaction/ram:ApplicableHeaderTradeAgreement/ram:BuyerTradeParty/ram:URIUniversalCommunication)`

Validate a document against these rules: https://xmlvalid.com/validate