Abn Entity Lookup

ABN Entity Lookup Skill

Queries the Australian Business Register (ABR) to validate ABNs, retrieve entity names, determine entity types, check GST registration status, and verify active/cancelled status. Essential for contractor deeming analysis, payroll tax compliance, and entity type determination.

When to Use

• Validating a contractor's ABN before classifying payments
• Determining entity type (company, trust, sole trader, partnership) for tax rate selection
• Checking GST registration status for input tax credit eligibility
• Verifying ABN is active (not cancelled) before processing payments
• Populating entity details for new Xero organisation connections
• Cross-referencing Xero contact ABNs for data quality checks

ABR API Configuration

Endpoint

https://abr.business.gov.au/abrxmlsearch/AbrXmlSearch.asmx/ABRSearchByABN

Parameters

Alternative Endpoints

ABN Validation Rules

Format Validation (Client-Side)

1. Must be exactly 11 digits 2. Apply ABN weighting algorithm:

• Subtract 1 from the first digit
• Multiply each digit by its weighting factor: [10, 1, 3, 5, 7, 9, 11, 13, 15, 17, 19]
• Sum the products
• Result must be divisible by 89

Example Validation

ABN: 51 824 753 556
Step 1: Subtract 1 from first digit → [4, 1, 8, 2, 4, 7, 5, 3, 5, 5, 6]
Step 2: Multiply by weights →          [40, 1, 24, 10, 28, 63, 55, 39, 75, 85, 114]
Step 3: Sum = 534
Step 4: 534 / 89 = 6.0 (exactly divisible) → VALID

Entity Type Mapping

ABR returns entity type codes that map to tax treatment:

Response Data Extraction

Key Fields

Output Format

<abn_lookup_result>
  <abn>51824753556</abn>
  <abn_valid>true</abn_valid>
  <abn_active>true</abn_active>
  <entity_name>Example Pty Ltd</entity_name>
  <entity_type>Australian Private Company</entity_type>
  <entity_type_code>PRV</entity_type_code>
  <gst_registered>true</gst_registered>
  <gst_effective_from>2015-07-01</gst_effective_from>
  <state>NSW</state>
  <postcode>2000</postcode>
  <acn>824753556</acn>

  <tax_implications>
    <corporate_tax_rate>0.25</corporate_tax_rate>
    <!-- Base rate entity test required (passive income <80%) -->
    <amendment_period_years>4</amendment_period_years>
    <payroll_tax_grouping_risk>related_body_corporate</payroll_tax_grouping_risk>
  </tax_implications>

  <lookup_metadata>
    <source>ABR API</source>
    <queried_at>2026-02-13T10:00:00+11:00</queried_at>
    <cache_ttl_hours>24</cache_ttl_hours>
  </lookup_metadata>
</abn_lookup_result>

Privacy Considerations

• ABR data is public information — no consent required for lookup
• However, caching ABR responses containing sole trader names has privacy implications under APP 11
• Sole trader lookups return individual names — handle with same care as personal information
• Cache ABR responses for 24 hours maximum, then re-query
• RLS policies on abn_lookup_cache table must restrict access to authenticated users only

Best Practices

• Always validate ABN format client-side before making API call
• Cache responses for 24 hours to reduce ABR API load
• Handle ABN not found gracefully — entity may have recently registered or cancelled
• Check GST status separately from ABN status — ABN can be active with cancelled GST
• Entity type determines tax rate, amendment period, and payroll tax grouping — always extract
• Rate limit ABR API calls — no published limit but be respectful (max 1 req/second)