# GR-R-001-4

Source: https://xmlvalid.com/rules/GR-R-001-4

> When Supplier is Greek, the Invoice Id third segment must be a positive integer

- 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($IdSegments[3]))>0 and string(number($IdSegments[3])) != 'NaN' and xs:integer($IdSegments[3]) >= 0`

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