ABN vs TFN vs ACN
Business identifier, personal tax number, company number.
A TFN is your personal tax number, yours for life. An ABN is an 11-digit number identifying a business — a sole trader has both. An ACN is a 9-digit number issued only to incorporated companies. So a sole trader has a TFN and an ABN; a company also has an ACN.
Worked example
Invoicing as a freelancer, you quote your ABN so the client doesn’t withhold tax. You give your TFN to your bank and super fund, never to a client. You’d only ever have an ACN if you registered a company.
Common mistake
Putting your TFN on an invoice. Your TFN is private and belongs to you personally — the ABN is the number that goes on business paperwork.
Grounded in ATO guidance. Figures last checked . General information, not tax advice.
Related terms
ABN (Australian Business Number)
The 11-digit number that identifies your business.
TFN (Tax File Number)
Your personal reference number in the tax system.
Sole trader
The simplest business structure — you and the business are one.
Sole trader tax rate
There isn’t one — you’re taxed at personal marginal rates.
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