errorsyntaxubl-2.1

UBL-SR-05:ID elements must be unique

Fix: Ensure each ID value is unique within its context.

ID elements within scope must have unique values.

Severity
Fatal
Rule set
ubl-2.1
Country
All EU
Fix type
CONFIRM
Confidence
90%
Category
structural

Engine Classification

Requires user confirmation before application

What is UBL-SR-05?

UBL-SR-05 is a fatal validation rule defined in the ubl-2.1 specification. It validates the PaymentTerms element in the UBL invoice XML.

When this rule fires, the invoice is rejected by Peppol access points and never reaches the buyer.

Target path: /Invoice/cac:PaymentTerms

Fix this error

Why This Error Matters

Invoice will be rejected by EN16931 validators. These structural constraints ensure consistent processing by receiving systems.

UBL-SR-05 is a hard failure — the invoice must be corrected and re-sent before it can reach the recipient.

Validator Behavior

  • ·Causes invoice rejection
  • ·Fails UBL schema validation
  • ·Error returned: UBL-SR-05
  • ·Specification: ubl-2.1

How to Fix It

1.

Check line IDs

InvoiceLine/ID must be unique

2.

Check other IDs

AllowanceCharge, TaxSubtotal, etc.

XML Example

Generic example based on the rule's target XPath. Your actual XML structure may differ.

Before
<!-- Required block is missing -->
<!-- <cac:PaymentTerms> ... </cac:PaymentTerms> -->
After
<!-- Add the required block -->
<cac:PaymentTerms>
  <!-- child elements -->
</cac:PaymentTerms>

Technical Reference

XPath/Invoice/cac:PaymentTerms
Specubl-2.1
Operationremove_duplicates
StrategyRemove duplicate payment terms, keeping the first occurrence

Common Causes

  • ·ERP system exports multiple references where only one is allowed in EN16931
  • ·Data consolidation merged records that should have been deduplicated
  • ·Template or mapping incorrectly configured to output duplicate elements
  • ·Manual editing introduced extra elements
  • ·Invoice conversion from another format did not merge duplicate entries

Seeing this in production? The API handles UBL-SR-05 automatically. See the fix response →

Frequently Asked Questions

ID elements within scope must have unique values.

Ensure each ID value is unique within its context. Invoice Navigator can propose a fix for this error, which you review and confirm before it is applied.

Yes, UBL-SR-05 is a critical error that will cause invoice rejection. It must be fixed before submission.

Related Errors

BR-CO-25In case the Amount due for payment (BT-115) is positive, either the Payment...

Related Content

Errors
Malformed XML structureInvalid XML characters
Regulations
EN 16931XRechnung

Last updated: 3 March 2026

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