# GR-R-001-5

Source: https://xmlvalid.com/rules/GR-R-001-5

> When Supplier is Greek, the Invoice Id in the fourth segment must be a valid greek document type

- Level: error
- Rule sets: Peppol BIS Billing 3.0 rules 3.0.21
- Context: `/ubl-invoice:Invoice/cbc:ID[$isGreekSender] | /ubl-creditnote:CreditNote/cbc:ID[$isGreekSender]`
- Test: `string-length(normalize-space($IdSegments[4]))>0 and (some $c in $greekDocumentType satisfies $IdSegments[4] = $c)`

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