Engine Classification
Financial or legal field · Modification blocked by policy
Reason: ERB compliance requires multiple Austrian-specific fields that cannot be auto-determined
What is AT-R-004?
AT-R-004 is a fatal validation rule defined in the erb specification (AUT national rules). It validates the XPath: Various ERB-specific requirements 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: XPath: Various ERB-specific requirements
Why This Error Matters
Required for Austrian federal government invoices.
AT-R-004 is a hard failure — the invoice must be corrected and re-sent before it can reach the recipient.
Validator Behavior
- ·Causes invoice rejection
- ·Error returned: AT-R-004
- ·Specification: erb
How to Fix It
Check ERB rules
Austrian federal e-invoice requirements
Validate format
Use ERB validator
XML Example
Generic example based on the rule's target XPath. Your actual XML structure may differ.
<!-- Triggers validation error --> <XPath: Various ERB-specific requirements></XPath: Various ERB-specific requirements>
<!-- Corrected --> <XPath: Various ERB-specific requirements>VALID_VALUE</XPath: Various ERB-specific requirements>
Technical Reference
XPath: Various ERB-specific requirementsCommon Causes
- ·Not ERB compliant
- ·Missing required fields
Seeing this in production? The API handles AT-R-004 automatically. See the fix response →
Frequently Asked Questions
Austrian B2G invoices must comply with ERB requirements.
Follow Austrian ERB specification for federal invoices. This error involves a protected field — Invoice Navigator flags it in your pipeline so your team can correct it at the source.
Yes, AT-R-004 is a critical error that must be fixed.
Related Errors
Related Content
Last updated: 3 March 2026
Validate your invoice
Drop your XML here to check for AT-R-004
Detect AT-R-004 before submission
This error involves a financial field that can't be auto-modified. We'll flag it with a clear diagnosis so you can fix it at the source.