How do I fix UBL-SR-48?

Invoice Navigator automatically fixes this Invoice compliance issue by updating the relevant XML elements (UBL-SR-48). You can also use Invoice Navigator's compliance engine to correct this automatically in your pipeline.

Is UBL-SR-48 a critical error?

Yes, UBL-SR-48 is a critical error that will cause invoice rejection. It must be fixed before submission.

Can UBL-SR-48 be automatically fixed?

Many instances of UBL-SR-48 can be automatically corrected using Invoice Navigator's compliance engine. The fix is applied in your pipeline with full audit evidence.

errorEN 16931

`UBL-SR-48`:Invoice line has wrong number of tax categories

Each invoice line must have exactly one tax category classification. One of your lines has either no tax category or multiple tax categories, which is not allowed.

Severity

Fatal

Rule set

EN 16931

Country

All EU

Fix type

AUTO-FIX

Confidence

80%

Engine Classification

For lines with multiple ClassifiedTaxCategory elements, keep only the first and remove duplicates. For lines missing ClassifiedTaxCategory, prompt user to add the tax category.

Confidence: 80% · Applied automatically in pipeline

What is UBL-SR-48?

UBL-SR-48 is a fatal validation rule defined in the EN 16931 specification. It validates the ClassifiedTaxCategory element under Item 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:InvoiceLine/cac:Item/cac:ClassifiedTaxCategory

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Why This Error Matters

Invoice will be rejected. Tax categorization per line is mandatory for VAT calculation and reporting.

UBL-SR-48 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: UBL-SR-48
·Specification: EN 16931

How to Fix It

Before / After

Failing XML

<Invoice>
  <!-- Issue: Invoice lines shall have one and only one classified tax cat -->
</Invoice>

Corrected XML

<Invoice>
  <!-- Issue resolved per EN 16931 -->
</Invoice>

Technical Reference

XPath//cac:InvoiceLine/cac:Item/cac:ClassifiedTaxCategory

SpecEN 16931

Operationremove_duplicates

StrategyFor lines with multiple ClassifiedTaxCategory elements, keep only the first and remove duplicates. For lines missing ClassifiedTaxCategory, prompt user to add the tax category.

Common Causes

·Invoice line created without assigning a tax category
·Multiple tax categories assigned to a single line item
·ERP export missing tax classification for some products
·Template does not enforce single tax category per line
·Tax category element accidentally duplicated or removed

Seeing this in production? The API handles UBL-SR-48 automatically. See the fix response →

Handle UBL-SR-48 Automatically in Your Pipeline

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

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UBL-SR-48:Invoice line has wrong number of tax categories