Hub ABN Validator
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ABN Validator

Validate any Australian Business Number using the official ATO check digit algorithm — instantly, in your browser, with no data sent anywhere.

0 / 11 digits
Formatted ABN
click to copy
Digit count

This tool validates the ABN format and check digit only. To look up the registered business name or details, visit the Australian Business Register at abr.gov.au.

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How to use
  1. Paste or type the 11-digit ABN — spaces and dashes are stripped automatically.
  2. The check digit algorithm runs instantly; a green tick confirms a structurally valid number.
  3. Click the formatted ABN to copy it, or use the ABR lookup link to verify the business details.
FAQ

An ABN (Australian Business Number) is a unique 11-digit identifier issued by the Australian Business Register to each business entity. Any business with a turnover of $75,000 or more must register for one.

The ATO algorithm subtracts 1 from the first digit, multiplies each of the 11 digits by the weighting factors [10, 1, 3, 5, 7, 9, 11, 13, 15, 17, 19], and checks the sum is divisible by 89.

No. It's an independent tool that implements the publicly documented ATO algorithm. A pass here means the number is mathematically correct — always confirm active registration via the ABR at abr.gov.au.