AT-01:Austrian sellers should include UID number
Fix: Review your Invoice XML structure and correct the issue described by this rule. Check relevant cbc: and cac: elements per CIUS-AT (Austria).
Austrian sellers should include UID number. This validation rule ensures Invoice compliance with CIUS-AT (Austria).
Engine Classification
Financial or legal field · Modification blocked by policy
What is AT-01?
AT-01 is a warning validation rule defined in the CIUS-AT (Austria) specification (AUT national rules).
The invoice may pass transmission, but this non-compliance can cause problems during tax audits or buyer-side processing.
Why This Error Matters
Austrian e-invoicing regulations require this for legal compliance. Invoices missing this information may be rejected by Austrian government portals and business partners.
AT-01 is a soft failure that can cause issues at the receiving end — tax audits, ERP processing, or VAT reconciliation mismatches.
Validator Behavior
- ·Generates validation warning
- ·Error returned: AT-01
- ·Specification: CIUS-AT (Austria)
How to Fix It
Identify the issue in your invoice
Austrian sellers should include UID number. This validation rule ensures Invoice compliance with CIUS-AT (Austria).
Correct this in your invoicing software
Review your Invoice XML structure and correct the issue described by this rule. Check relevant cbc: and cac: elements per CIUS-AT (Austria).
Re-export and validate
Generate a new invoice export from your accounting system and re-validate to confirm AT-01 is resolved.
Before / After
<Invoice> <!-- Issue: Austrian sellers should include UID number --> </Invoice>
<Invoice> <!-- Issue resolved per CIUS-AT (Austria) --> </Invoice>
Technical Reference
Seeing this in production? The API handles AT-01 automatically. See the fix response →
Frequently Asked Questions
Austrian sellers should include UID number. This validation rule ensures Invoice compliance with CIUS-AT (Austria).
Review your Invoice XML structure and correct the issue described by this rule. Check relevant cbc: and cac: elements per CIUS-AT (Austria). You can also use Invoice Navigator's compliance engine to correct this automatically in your pipeline.
AT-01 is a warning that may not always cause rejection, but indicates a compliance issue.
Many instances of AT-01 can be automatically corrected using Invoice Navigator's compliance engine. The fix is applied in your pipeline with full audit evidence.
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Last updated: 14 April 2026
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