Skip to content
Change language: English

Warning

UBL-CR-598: A line's VAT category should not carry a base unit

In short

Warning: worth checking.

UBL-CR-598 means the VAT category of an item on an invoice or credit note line has a base unit measure (cbc:BaseUnitMeasure), which EN 16931 does not use. It is a warning. Remove the element and keep the VAT category code (BT-151) and any applicable VAT rate (BT-152).

On this page

What it means

The rule looks at the item on every invoice line (or credit note line) in a UBL file. It warns when the item's VAT details (cac:ClassifiedTaxCategory) contain a cbc:BaseUnitMeasure, a base quantity used for a per-unit tax. The rule checks only for this element, not the VAT category code (BT-151), VAT rate (BT-152) or VAT scheme.

Why it matters

EN 16931 does not use a base unit measure within a line's classified tax category.

How to fix it

Check the export mapping of your invoicing software for cbc:BaseUnitMeasure in the line's VAT category and omit it from the export. If you build the XML yourself, delete cbc:BaseUnitMeasure from cac:ClassifiedTaxCategory under cac:InvoiceLine/cac:Item (cac:CreditNoteLine in a credit note). Keep cbc:ID and any applicable cbc:Percent unchanged.

Once the file is corrected, check it again for free: Validate an invoice against EN 16931

Or fix the invoice in a form and download the corrected file, for 1 credit: Fix a rejected e-invoice

The rule as published

A UBL invoice should not include the InvoiceLine Item ClassifiedTaxCategory BaseUnitMeasure

Where this rule applies

Rule set Version
EN 16931 (UBL) 1.3.17
EN 16931 (UBL credit note) 1.3.17
XRechnung 3.0 (UBL) 3.0.2
XRechnung 3.0 (UBL credit note) 3.0.2
Peppol BIS Billing 3.0 (invoice) 2026.5
Peppol BIS Billing 3.0 (credit note) 2026.5
SI-UBL 2.0 / NLCIUS (invoice) 2.0.3.13
SI-UBL 2.0 / NLCIUS (credit note) 2.0.3.13
France CTC (UBL invoice) 1.4.0-04
France CTC (UBL credit note) 1.4.0-04
CIUS-RO UBL Invoice 1.0.9 1.0.9
CIUS-RO UBL Credit Note 1.0.9 1.0.9
Rule text from phive-rules 4.6.4.

Check your file

Drop your e-invoice to see whether UBL-CR-598 still fails, and which other rules do.

Updated 6 November 2026