Topic guide
ACN and TFN Number Checkers
Check an Australian company number or tax file number for format and checksum errors.
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Choose the Identifier to Check
Choose a number checker for the identifier on your document. An Australian company number (ACN) identifies a registered company. A tax file number (TFN) identifies an individual or organisation for tax purposes.
Use the ACN checker for a company number. ACNs and TFNs follow different checking rules, so use the matching check even when two numbers have the same length.
A format check examines the number’s structure. A checksum applies a calculation to its digits to detect some typing errors. A passing result means the number satisfies those checks.
A valid checksum does not establish company registration, ownership of the number or the identity of the person supplying it. If a number fails, compare it with the original document before changing a client record. Registration searches and identity verification are separate checks.
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Choose the tool you need
4 checkers
- Bank Statement Analyser
Analyse a bank-statement CSV locally to total income, expenses and recurring payments. Review categories and trace monthly figures to transactions.
- ACN Checker
Check an ACN's length and check digit using ASIC's published formula. Format the number and distinguish a checksum result from a company-register lookup.
- TFN Checker
Check a TFN's format and checksum locally in your browser. See whether the digits pass the arithmetic check without looking up a person's tax record.
- SMS Character Counter
Count SMS characters and message segments before sending. See how Unicode, emoji and extended characters change the encoding and segment total.