International · Validation
Australian Registered Body Number (ARBN) validator.
Check a 9-digit ARBN, the number ASIC gives registered foreign companies and other registered bodies, or an ARSN. ASIC says both are built with the same formula as an ACN, and this tool shows each step.
How it works: multiply the first eight digits by 8, 7, 6, 5, 4, 3, 2, 1 and add them. Divide by 10, subtract the remainder from 10 (a result of 10 becomes 0), and the answer must equal the ninth digit.
Inputs
Result
Enter a number and press Check.
How the ARBN and ARSN check digit works
ASIC describes the Australian Company Number as a nine digit number whose last digit is a check digit from a modified modulus 10 calculation. Its digit-check page then adds that Australian Registered Body Numbers (ARBNs) and Australian Registered Scheme Numbers (ARSNs) are constructed using the same formula. ASIC's glossary describes an ARBN as a unique 9-digit number that ASIC gives to registered bodies once they are registered, which covers local registered bodies and overseas companies.
| Step | What happens |
|---|---|
| 1 | Weight digits 1 to 8 by 8, 7, 6, 5, 4, 3, 2, 1: 0, 0, 24, 0, 32, 15, 12, 1 |
| 2 | Add them: 84 |
| 3 | Divide by 10: remainder 4 |
| 4 | Complement the remainder to 10: 10 − 4 = 6. If the complement is 10, set it to 0 |
| 5 | 6 equals the ninth digit, so the check digit is correct |
Why the tool cannot tell an ARBN from an ACN
The three numbers share one formula, so a passing result only tells you the nine digits are well formed. It cannot say whether they are an ACN, an ARBN or an ARSN. Looking the number up on an ASIC register is the way to find out.
Format check, not an ASIC search
A valid check digit does not show that a body holds the number. To confirm a registered body, search ASIC's registers or ABN Lookup. To work out the ABN that ends in the same nine digits, see the ACN to ABN converter.
Sources
- ASIC: Australian Company Number digit check (archived 2024; ARBN and ARSN note)
- ASIC glossary: Australian Registered Body Number (ARBN)
Retrieved October 2026. Agencies can change these rules; check the issuing authority if a result matters.
FAQ
What is an ARBN?
An Australian Registered Body Number, a 9-digit number ASIC gives to registered bodies, including foreign companies registered to do business in Australia.
How is the ARBN check digit calculated?
ASIC says ARBNs and ARSNs are constructed with the same formula as ACNs. The first eight digits are weighted 8 down to 1 and added; the remainder after dividing by 10 is subtracted from 10, with 10 set to 0; the result must equal the ninth digit.
What is an ARSN?
An Australian Registered Scheme Number. ASIC says it is built with the same formula as an ACN, so this tool checks it the same way.
Can this tell me whether a number is an ARBN or an ACN?
No. Both pass the same test, so a passing number is only well formed. A register search shows which kind it is.
Is the number I type sent anywhere?
No. The check runs in your browser and nothing you type is transmitted, stored or logged.
Check digit only, not a register lookup
This tool tests the structure and check digit of the number in your browser. It does not query any ASIC register, and a passing result does not show the number was issued or is still registered. To confirm that, look it up on ABN Lookup or search ASIC. Nothing you type is transmitted, stored or logged.