errorEN 16931

BR-CO-19:Invoice period must have at least one date

If Invoicing period (BG-14) is used, the Invoicing period start date (BT-73) or the Invoicing period end date (BT-74) shall be filled, or both.

Severity
Fatal
Rule set
EN 16931
Country
All EU
Fix type
AUTO-FIX
Confidence
85%
Category
structural

Engine Classification

Remove empty invoice period elements that lack both start and end dates

Confidence: 85% · Applied automatically in pipeline

What is BR-CO-19?

BR-CO-19 is a fatal validation rule defined in the EN 16931 specification. It validates the InvoicePeriod element in the UBL invoice XML.

When this rule fires, the invoice is non-compliant and will be rejected by Peppol access points and national validation services. The sending system receives a rejection response and the invoice does not reach the buyer.

Target path: //cac:InvoicePeriod[not(cbc:StartDate) and not(cbc:EndDate)]

Why This Error Matters

An empty invoice period element serves no purpose and violates the EN16931 specification. If you include an invoice period, it must specify at least one date to indicate the billing period covered.

BR-CO-19 is a hard failure. Invoices that trigger this rule are rejected at the access point and never reach the recipient. In Peppol networks, this means your sending system receives an MLR (Message Level Response) with a rejection status. The invoice must be corrected and re-sent, adding delay to your payment cycle.

Invoice Navigator can automatically correct this error in your pipeline. The fix is applied with full audit evidence, so your compliance trail remains intact.

Validator Behavior

  • ·Causes invoice rejection
  • ·Error returned: BR-CO-19
  • ·Specification: EN 16931

How to Fix It

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Before / After

Failing XML
<cac:InvoicePeriod>\n  <!-- Empty - no dates -->\n</cac:InvoicePeriod>
Corrected XML
<cac:InvoicePeriod>\n  <cbc:StartDate>2026-01-01</cbc:StartDate>\n  <cbc:EndDate>2026-01-31</cbc:EndDate>\n</cac:InvoicePeriod>

Technical Reference

XPath//cac:InvoicePeriod[not(cbc:StartDate) and not(cbc:EndDate)]
SpecEN 16931
Operationremove
StrategyRemove empty invoice period elements that lack both start and end dates

Code Example

<!-- Option 1: Add dates -->\n<cac:InvoicePeriod>\n  <cbc:StartDate>2026-01-01</cbc:StartDate>\n  <cbc:EndDate>2026-01-31</cbc:EndDate>\n</cac:InvoicePeriod>\n\n<!-- Option 2: Remove empty element entirely -->

Common Causes

  • ·Template includes empty InvoicePeriod by default
  • ·Export process creates structure without populating dates
  • ·Copy-paste from another invoice forgot to update dates
  • ·Conditional logic error in invoice generation

Seeing this in production? The API handles BR-CO-19 automatically. See the fix response →

Frequently Asked Questions

BR-CO-19 occurs when an InvoicePeriod element exists in the invoice but contains no StartDate (BT-73) or EndDate (BT-74). The period element must have at least one date.

Either add dates to the invoice period (StartDate and/or EndDate), or remove the empty InvoicePeriod element entirely. Invoice Navigator can fix this automatically.

Yes, BR-CO-19 is a business rule violation that will cause invoice rejection. An invoice period must have at least one date to be valid.

Yes! Invoice Navigator automatically removes empty InvoicePeriod elements when no dates are present. This is a safe structural fix with no data loss.

See Also

Related Errors

Last updated: 27 February 2026

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Handle BR-CO-19 Automatically in Your Pipeline

The compliance engine auto-remediates this error with controlled safety policies and evidence pack generation.