1. U4 ERPx
  2. Business cases
  3. Supplier VAT Number Validation

Supplier VAT Number Validation

Automatically validate supplier VAT registration numbers against the EU VIES (VAT Information Exchange System) database to ensure compliance with single market law, verify supplier legitimacy, and maintain accurate tax reporting for intra-EU transactions.

Key APIs used

  • GET /v1/objects/suppliers - Retrieve ERPx supplier records for validation.
  • GET /v1/suppliers/{id} - Fetch individual supplier details with VAT number.
  • PATCH /v1/suppliers/{id} - Update supplier record with validation results.
  • GET /v1/custom-fields/ - Retrieve validation status and audit trail fields.
  • PATCH /v1/custom-fields/ - Update flexi-fields with validation history.
  • GET /v1/objects/clients - Retrieve configured ERPx clients for validation.

Integration workflow

sequenceDiagram
    participant API as ERPx API
    participant EIT as Extension/Integration toolkit
    participant VIES as VAT validation service

    Note over API,VIES: Trigger: Supplier creation or scheduled 

    EIT->>API: 1. GET /v1/suppliers/{id}
    API-->>EIT: Supplier with VAT number

    EIT->>API: 2. Validate VAT format & country code
    API-->>EIT: Validation passed

    EIT->>API: 3. GET /v1/suppliers/{id}
    EIT->>VIES: SOAP request (VAT, Name, Address)
    VIES-->>EIT: Validation result (Valid/Invalid)
    EIT-->>API: VAT validation status

    EIT->>API: 4. PATCH /v1/suppliers/{id}
    EIT-->>API: Supplier updated with status

    EIT->>API: 5. PATCH /v1/custom-fields/A5
    EIT-->>API: Audit trail recorded

For detailed API specifications, request/response formats, and authentication details, refer to: