PEPPOL-EN16931-R051:Currency codes are not consistent
Fix: Invoice Navigator automatically fixes this issue by correcting the `cbc:PrepaidAmount` element in your Invoice (PEPPOL-EN16931-R051). Upload your invoice to fix this automatically.
All amounts in the invoice must use the same currency, matching the document currency code. For example, if the invoice is in EUR, every amount, tax total, line item, and allowance/charge must also use EUR as the currency code. The only exception is the accounting currency tax amount (BT-111).
Engine Classification
Sets all currencyID attributes to match the DocumentCurrencyCode
Confidence: 95% · Applied automatically in pipeline
What is PEPPOL-EN16931-R051?
PEPPOL-EN16931-R051 is a fatal validation rule defined in the Peppol BIS 3.0 specification. It validates the @currencyID 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: //@currencyID
Why This Error Matters
Invoice will be rejected by PEPPOL validation. Mixed currencies (except for accounting VAT) are not allowed.
PEPPOL-EN16931-R051 is a hard failure — the invoice must be corrected and re-sent before it can reach the recipient.
Mixed currencies make the invoice ambiguous and impossible to process. The receiver does not know which currency to pay in. Validation systems reject invoices with inconsistent currencies.
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
- ·Rejected by PEPPOL Access Points
- ·Error returned: PEPPOL-EN16931-R051
- ·Specification: Peppol BIS 3.0
How to Fix It
Find the document currency
Check the DocumentCurrencyCode at the top of the invoice (e.g. EUR, SEK, GBP).
Check all amounts
Every amount in the invoice should have currencyID matching the document currency.
Fix mismatches
Update any currencyID attributes that do not match. The only exception is BT-111 (accounting currency tax amount) if a TaxCurrencyCode is specified.
Before / After
<cac:LegalMonetaryTotal> <cbc:PrepaidAmount><!-- invalid or missing value --></cbc:PrepaidAmount> </cac:LegalMonetaryTotal>
<cac:LegalMonetaryTotal> <cbc:PrepaidAmount>correct-value</cbc:PrepaidAmount> </cac:LegalMonetaryTotal>
Technical Reference
//@currencyIDCommon Causes
- ·ERP uses different currency fields for headers and lines
- ·Template has hardcoded currency that differs from invoice currency
- ·Copy-paste from invoice with different currency
Seeing this in production? The API handles PEPPOL-EN16931-R051 automatically. See the fix response →
Commonly Seen In
Frequently Asked Questions
All amounts in the invoice must use the same currency, matching the document currency code. For example, if the invoice is in EUR, every amount, tax total, line item, and allowance/charge must also use EUR as the currency code. The only exception is the accounting currency tax amount (BT-111).
Invoice Navigator automatically fixes this issue by correcting the `cbc:PrepaidAmount` element in your Invoice (PEPPOL-EN16931-R051). You can also use Invoice Navigator's compliance engine to correct this automatically in your pipeline.
Yes, PEPPOL-EN16931-R051 is a critical error that will cause invoice rejection. It must be fixed before submission.
Many instances of PEPPOL-EN16931-R051 can be automatically corrected using Invoice Navigator's compliance engine. The fix is applied in your pipeline with full audit evidence.
PEPPOL-EN16931-R051 is commonly seen in exports from All invoicing software. These packages sometimes generate invoices that need adjustment.
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Last updated: 27 February 2026
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