How do I fix UBL-SR-15?

Your invoice contains multiple Buyer name elements (AccountingCustomerParty/Party/PartyName/Name). EN16931 allows only one buyer name. You can also use Invoice Navigator's compliance engine to correct this automatically in your pipeline.

Is UBL-SR-15 a critical error?

Yes, UBL-SR-15 is a critical error that will cause invoice rejection. It must be fixed before submission.

Can UBL-SR-15 be automatically fixed?

Many instances of UBL-SR-15 can be automatically corrected using Invoice Navigator's compliance engine. The fix is applied in your pipeline with full audit evidence.

errorEN16931

`UBL-SR-15`:Buyer name shall occur maximum once

Your invoice contains multiple Buyer name elements (AccountingCustomerParty/Party/PartyName/Name). EN16931 allows only one buyer name.

Severity

Fatal

Rule set

EN16931

Country

All EU

Fix type

CONFIRM

Confidence

90%

Engine Classification

Requires user confirmation before application

What is UBL-SR-15?

UBL-SR-15 is a fatal validation rule defined in the EN16931 specification. It validates the RegistrationName element under Party > PartyLegalEntity 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: /Invoice/cac:AccountingCustomerParty/cac:Party/cac:PartyLegalEntity/cbc:RegistrationName

Get API Access

Why This Error Matters

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

UBL-SR-15 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.

Validator Behavior

·Causes invoice rejection
·Fails EN 16931 business rule validation
·Error returned: UBL-SR-15
·Specification: EN16931

XML Example

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

Before

<!-- Missing or empty element triggers cbc:RegistrationName error -->
<cbc:RegistrationName></cbc:RegistrationName>

After

<!-- Provide the required value -->
<cbc:RegistrationName>VALID_VALUE</cbc:RegistrationName>

Technical Reference

XPath/Invoice/cac:AccountingCustomerParty/cac:Party/cac:PartyLegalEntity/cbc:RegistrationName

SpecEN16931

Operationremove_duplicates

StrategyRemove duplicate buyer registration names, 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-15 automatically. See the fix response →

Handle UBL-SR-15 Automatically in Your Pipeline

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

Get API Access View API Documentation

UBL-SR-15:Buyer name shall occur maximum once