Reference

BR-CO-20 Invoice line period needs a start or end date

If the 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.

Problem Description

If the 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

XRechnung 3.0

Context and Significance

This EN16931 core rule is the line-level counterpart of BR-CO-19, preventing an empty line period group with no delivery or service timeframe.

Solution

When a cac:InvoicePeriod appears inside an invoice line, provide at least a StartDate (BT-134) or an EndDate (BT-135).

Validate XML Convert invoice

Valid Examples

Use these points as the practical checks for this section.

BT-134 = 2026-02-01 with BT-135 = 2026-02-28

Invalid Examples

Use these points as the practical checks for this section.

Line cac:InvoicePeriod present but neither BT-134 nor BT-135 filled

Code Examples

Valid XML

<cac:InvoiceLine>
  <cac:InvoicePeriod>
    <cbc:StartDate>2026-02-01</cbc:StartDate>
    <cbc:EndDate>2026-02-28</cbc:EndDate>
  </cac:InvoicePeriod>
</cac:InvoiceLine>

Invalid XML

<cac:InvoiceLine>
  <cac:InvoicePeriod>
    <cbc:DescriptionCode>3</cbc:DescriptionCode>
  </cac:InvoicePeriod>
</cac:InvoiceLine>

Affected Fields

BG-26 Invoice line period

BT-134 Invoice line period start date

BT-135 Invoice line period end date

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