cvc-datatype-valid.1.2.1:Invoice field value does not match the required data format
Fix: Invoice Navigator can attempt to normalize common formatting errors like decimal separators and date formats. Upload your invoice to fix this automatically.
A value in your invoice does not match the data format required by the XML Schema. This typically means a number, date, or other value is formatted incorrectly — for example, using a comma instead of a dot for decimals (1.234,56 instead of 1234.56), or a date in DD/MM/YYYY format instead of the required YYYY-MM-DD (ISO 8601).
Engine Classification
Parse the error message to identify the invalid value and target type, then normalize common formatting issues (decimal separator, date format, boolean)
Confidence: 75% · Applied automatically in pipeline
What is cvc-datatype-valid.1.2.1?
cvc-datatype-valid.1.2.1 is a fatal validation rule defined in the xsd specification. It validates the __from_error_message__ 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: __from_error_message__
Why This Error Matters
cvc-datatype-valid.1.2.1 is a hard failure — the invoice must be corrected and re-sent before it can reach the recipient.
Incorrectly formatted values make the invoice unparseable by receiving systems. Even if the intended value is correct, the wrong format means automated processing will reject the invoice.
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: cvc-datatype-valid.1.2.1
- ·Specification: xsd
How to Fix It
Check the error details
The error message identifies the invalid value and what type was expected. For example: '1.234,56 is not a valid value for decimal' means the number uses continental formatting.
Fix number formatting
Use dot (.) as decimal separator, no thousand separators: 1234.56, not 1.234,56 or 1,234.56.
Fix date formatting
Use ISO 8601 format: YYYY-MM-DD (e.g., 2026-03-12), not DD/MM/YYYY or MM/DD/YYYY.
Update software locale settings
If this error occurs consistently, check your invoicing software's locale and number format settings for XML export.
XML Example
Generic example based on the rule's target XPath. Your actual XML structure may differ.
<!-- Triggers validation error --> <__from_error_message__></__from_error_message__>
<!-- Corrected --> <__from_error_message__>VALID_VALUE</__from_error_message__>
Technical Reference
__from_error_message__Common Causes
- ·UK or continental number formatting with comma decimals (1.234,56)
- ·Dates in DD/MM/YYYY instead of ISO 8601 YYYY-MM-DD
- ·Thousand separators in numeric fields (1,234.56)
- ·Boolean values as Yes/No instead of true/false
- ·Currency amounts with locale-specific formatting
Seeing this in production? The API handles cvc-datatype-valid.1.2.1 automatically. See the fix response →
Commonly Seen In
Frequently Asked Questions
A value in your invoice does not match the data format required by the XML Schema. This typically means a number, date, or other value is formatted incorrectly — for example, using a comma instead of a dot for decimals (1.234,56 instead of 1234.56), or a date in DD/MM/YYYY format instead of the required YYYY-MM-DD (ISO 8601).
Invoice Navigator can attempt to normalize common formatting errors like decimal separators and date formats. You can also use Invoice Navigator's compliance engine to correct this automatically in your pipeline.
Yes, cvc-datatype-valid.1.2.1 is a critical error that will cause invoice rejection. It must be fixed before submission.
Many instances of cvc-datatype-valid.1.2.1 can be automatically corrected using Invoice Navigator's compliance engine. The fix is applied in your pipeline with full audit evidence.
cvc-datatype-valid.1.2.1 is commonly seen in exports from Invoicing software using locale-dependent formatting for XML export, ERP systems not converting to XML-standard formats, Custom invoice generators. These packages sometimes generate invoices that need adjustment.
Related Errors
Related Content
Last updated: 12 March 2026
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