BR-CO-20

If Invoice line period (BG-26) is used, the Invoice line period start date (BT-134) or the Invoice line period end date (BT-135) shall be filled, or both.

error: the document is invalid Peppol documentation ↗

What the rule checks

As the rule set's publisher wrote it. The rule runs on every element the context matches, and fails where the test is false; the validator reports the line of that element.

Context
//ram:SpecifiedLineTradeSettlement/ram:BillingSpecifiedPeriod
Test
(ram:StartDateTime) or (ram:EndDateTime)

Checked with EN 16931 Invoice (CII)