BR-DEC-21:Tax total: max 2 decimals
TaxTotal/TaxAmount allows maximum 2 decimal places.
Engine Classification
Financial or legal field · Modification blocked by policy
Reason: Tax total amounts must have maximum 2 decimal places. Automatic rounding of tax amounts is not permitted as it affects VAT calculations. Fix the tax calculation in your source system to produce proper 2-decimal values.
What is BR-DEC-21?
BR-DEC-21 is a fatal validation rule defined in the en16931 specification. It validates the TaxAmount element under Invoice > TaxTotal 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: XPath: /Invoice/cac:TaxTotal/cbc:TaxAmount
Why This Error Matters
Total VAT must have proper precision.
BR-DEC-21 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: BR-DEC-21
- ·Specification: en16931
How to Fix It
Check tax total
TaxTotal/TaxAmount precision
Round
Sum of subtotals, rounded
XML Example
Generic example based on the rule's target XPath. Your actual XML structure may differ.
<!-- Missing or empty element triggers cbc:TaxAmount error --> <cbc:TaxAmount></cbc:TaxAmount>
<!-- Provide the required value --> <cbc:TaxAmount>VALID_VALUE</cbc:TaxAmount>
Technical Reference
XPath: /Invoice/cac:TaxTotal/cbc:TaxAmountCommon Causes
- ·Sum of rounded subtotals may need rounding
Seeing this in production? The API handles BR-DEC-21 automatically. See the fix response →
Frequently Asked Questions
TaxTotal/TaxAmount allows maximum 2 decimal places.
Round total VAT to 2 decimals. This error involves a protected field — Invoice Navigator flags it in your pipeline so your team can correct it at the source.
Yes, BR-DEC-21 is a critical error that will cause invoice rejection. It must be fixed before submission to ensure your invoice is accepted by the recipient's system.
BR-DEC-21 involves a financial or legal field that cannot be auto-modified by policy. Invoice Navigator detects and flags this error immediately, but the correction must be made manually in your ERP or invoicing software.
Related Content
Last updated: 3 March 2026
Detect BR-DEC-21 Before Submission
This error involves a financial or legal field that cannot be auto-modified. The compliance engine flags it immediately with a clear diagnosis so your team can fix it at the source.