HU-R-004:Hungarian VAT code required
Fix: Map VAT category to Hungarian code. Provide the required value in the free validator.
NAV requires Hungarian-specific VAT category codes.
Engine Classification
Business data required · Explicit input workflow · No assumptions made
Required input: Hungarian VAT Category
What is HU-R-004?
HU-R-004 is a fatal validation rule defined in the nav specification (HUN national rules). It validates the XPath: Extension for NAV VAT code 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: Extension for NAV VAT code
Why This Error Matters
NAV uses specific VAT categorization.
HU-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: HU-R-004
- ·Specification: nav
How to Fix It
Map VAT
EN16931 to Hungarian category
Add code
AAM, TAM, etc.
XML Example
Generic example based on the rule's target XPath. Your actual XML structure may differ.
<!-- Triggers validation error --> <XPath: Extension for NAV VAT code></XPath: Extension for NAV VAT code>
<!-- Corrected --> <XPath: Extension for NAV VAT code>VALID_VALUE</XPath: Extension for NAV VAT code>
Technical Reference
XPath: Extension for NAV VAT codeCommon Causes
- ·Missing Hungarian VAT code
- ·Wrong mapping
Seeing this in production? The API handles HU-R-004 automatically. See the fix response →
Frequently Asked Questions
NAV requires Hungarian-specific VAT category codes.
Map VAT category to Hungarian code. Invoice Navigator detects this error and prompts for the required business data before applying a safe fix.
Yes, HU-R-004 is a critical error that must be fixed.
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Last updated: 3 March 2026
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