AT-R-004:ERB (e-Rechnung Bund) compliance required
Austrian B2G invoices must comply with ERB requirements.
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 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: Various ERB-specific requirements
Why This Error Matters
Required for Austrian federal government invoices.
AT-R-004 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
- ·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 Content
Last updated: 3 March 2026
Detect AT-R-004 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.