Learn the difference between ACN, ABN, and TFN in Australia. Find out which numbers your business really needs and why they matter for tax and compliance
ACN stands for Australian Company Number. It’s a unique 9-digit unique number issued to every company registered in Australia.
The Australian Securities and Investments Commission (ASIC) issues ACNs when a company is registered.
Identifies your company on the ASIC register.
Used on official company documents and legal paperwork.
Helps distinguish your company from others with similar names.
Only if you are registering a company. Sole traders, trusts and partnerships don’t get an ACN.
Example:
ACN: 123 456 789
Think of ACN as your company’s “ID card” with ASIC.
ABN stands for Australian Business Number. It’s a unique 11-digit number used for business dealings with the government and other businesses.
The Australian Taxation Office (ATO) issues ABNs through the business registration process.
Identifies your business for tax purposes.
Allows you to register for GST, PAYG withholding, and other business taxes.
Needed for invoicing, claiming GST credits, and dealing with other businesses.
Yes, if you’re running a business, regardless of the structure - a sole trader, partnership, company, or trust - you need an ABN.
Example:
ABN: 12 345 678 901
ABN is like your business “passport” for dealing with other businesses and the government.
TFN stands for Tax File Number. It is a unique 9-digit number issued to individuals, companies, partnerships, trusts, and superannuation funds for tax purposes.
The Australian Taxation Office (ATO) issues ABNs through the business registration process.
Used for income tax and other tax reporting.
You need it to open bank accounts, apply for government benefits, and lodge tax returns.
Yes. Every person and entity earning income or operating a business in Australia must have a TFN.
Example:
TFN: 123 456 789
TFN is your personal or business “tax ID.”
ANNA +Taxes is available for newly registered companies – first 1,000 customers get 6 months free. We auto-categorise your transactions and take care of your lodgements.
Register NowACN: ASIC company register or Company legal documents
ABN: ABN Lookup tool
TFN: myGov account or ATO correspondence
ACN: Publicly available on ASIC, so safe to share
ABN: Safe to share for business purposes
TFN: Keep private to prevent identity theft
ABN: This is the main number you should include on invoices for all businesses. Including your ABN makes sure your invoice meets ATO requirements and allows clients to claim GST credits
ACN: It’s not mandatory for invoices. Only companies registered with ASIC can display an ACN on invoices, but it’s not necessary if your ABN is already listed. Sole traders, partnerships, and trusts don’t have an ACN
TFN: Never include your TFN on invoices. TFNs are private tax identifiers and should be kept confidential to prevent identity theft
Check the ATO website for more details about requirements of tax invoices
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