How to Obtain a Business a TFN in Australia: A Guide for Startups

A Guide for Business Owners & Founders of StartUps

Obtaining your business Tax File Number (TFN) isn’t just admin — it’s your business’s identity in the eyes of the ATO. Without it, you can’t trade properly, lodge tax returns, or meet basic legal obligations.

In 2020, a new hospitality business in Sydney made headlines after it was fined for trading without the correct tax registrations — including a missing TFN. They had a fit-out, staff ready, even clients lined up — but were forced to delay opening because their tax file number wasn’t processed in time.

That one missing step cost them thousands.

Don’t let red tape hold you back. Here’s exactly how to register for a TFN so you can operate legally and confidently from day one.

Get your TFN sorted early and set yourself up for growth, not headaches.

What Is a TFN (Tax File Number)?

A TFN is a unique number issued by the Australian Taxation Office (ATO) to identify you for tax and super purposes.

• Individuals need a TFN to file personal tax returns, claim tax offsets, or apply for government benefits.

  
  

• Businesses need a TFN to lodge returns, deal with GST and PAYG, open business bank accounts, and apply for other registrations (like an ABN).

Mentor Tip: Think of your TFN as your tax passport. Without it, key parts of your business can’t legally operate.

Why It Matters for Business Owners

1. It unlocks other business registrations

You’ll need a TFN to register for GST, PAYG withholding, and other ATO-related services.

2. It helps keep your finances clean

Having a TFN allows your income, expenses, and tax obligations to be correctly tracked.

3. It avoids penalties and tax delays

Failing to register can lead to interest charges, ATO disputes, or missed deductions.

4. It positions your business for growth

Want to bring on investors, borrow money, or apply for grants? You’ll need to show tax compliance.

Mentor Tip: Investors and lenders take one look at your tax setup. A missing TFN can raise red flags before you even pitch.

What You’ll Need Before You Register

Before starting your application, get these ready:

• Your Australian Business Number (ABN)

• Business structure (sole trader, partnership, company, trust)

• ACN (if you’re a company)

• Business address and contact details

• ID documents (e.g. driver’s licence, passport, Medicare card)

Having these upfront avoids delays and helps you complete the process in one go.

How to Obtain a Business TFN:

Step-by-Step for Business

TFN for Companies in Australia: What to Know

• Sole traders use their personal TFN for business.

• Companies, trusts, partnerships must apply for a separate business TFN.

• Unsure which applies? [Internal Link: Sole Trader vs Company Guide]

Step 1: Know Who You’re Registering For

• Sole traders use their personal TFN for business

• Companies, trusts, and partnerships must apply for a separate business TFN

Mentor Tip: If you’re not sure which applies, speak with your accountant before submitting the form.

Step 2: Choose the Right Registration Method

• Sole traders can register for a TFN online via the ATO or when applying for an ABN

• Companies/trusts/partnerships apply using the ATO’s paper form (form NAT 3799)

Step 3: Complete the Business TFN Application

For companies/trusts/partnerships:

• Download NAT 3799 from the ATO

• Fill out the details of your entity, responsible persons, and business activities

• Attach supporting ID documents

Step 4: Lodge the Form

• Mail the completed form to: Australian Taxation Office PO Box 9942 MOONEE PONDS VIC 3039 (keep a copy for your records)

Warning: TFN registration is free. Be cautious of third-party services charging fees unless you’re getting expert advice bundled in.

Step 5: Wait for Confirmation

• It can take up to 28 days to receive your TFN via mail (for businesses)

• You’ll then be able to register for other ATO services (GST, PAYG, etc.)

How Much Does It Cost and How Long Does It Take?

Here’s what to expect:

• TFN registration: Free

• Processing time: Up to 28 days for paper lodgement (businesses); faster for individuals

• Additional services (if using a consultant): $100–$300

Money-Saving Tip: Do it yourself via the ATO unless you need tailored tax advice. Most founders can complete the form in under 30 minutes.

Common Mistakes Business Owners Make

Applying under the wrong structure 

Register as a sole trader when you're actually a company? Mismatched records = future headaches.

Waiting too long to apply 

If you think “I’ll get the TFN once I start making money,” you’re already late. No TFN = withheld payments, missed BAS deadlines, and a scramble you didn’t need.

Stuffing up your ID 

Expired license, wrong name, missing info — any of these will slow the process to a crawl. Triple-check your ID before you hit submit.

Paying for what’s already free 

Basic TFN registration is free through the ATO. If you're paying someone, they better be offering real advice — not just pressing buttons you could click yourself.

What to Do Right Now

✅ Download Business Checklists

Your quick-start tool for business owners who want to apply with clarity and confidence. Built for Australian businesses. [Download at ProDesk.com]

✅ Need help? Book with Noize

Noize helps business owners setup the right way, stay protected, and align their tax setup with long-term strategy. We take the guesswork out of tax compliance and can design highly profitable growth strategies so you can focus on building your business. [Book at Noize.com.au]

✅ Get the full StartUp Deck

This 360° business toolkit gives you the templates, checklists, and strategies to build a startup from idea to execution. Comes with 6 months free access to ProDesk. [TheStartUpDeck.com]

The Bottom Line

Your TFN is your ticket to tax compliance in Australia. Without it, your business simply can’t function properly. Get it sorted early and set yourself up for growth, not headaches.

Start now. It’s free, fast, and one of the simplest wins in early-stage business compliance.

FAQs for TFN Registration 

Do I need a separate TFN for my business in Australia?

If you're a sole trader, you can use your personal TFN for business purposes. But if you run a company, trust, or partnership, you must apply for a separate TFN through the ATO.

How do I register for a TFN as a company or trust?

To register for a TFN as a non-individual (e.g. company or trust), download and complete NAT 3799 from the ATO’s website. Mail it with supporting documents.

Can I operate a business without a TFN in Australia?

Technically yes — but it’s not recommended. Without a TFN, your business can’t register for GST, PAYG, or lodge tax returns. It may also face withholding tax at 47% from other businesses.

Is TFN registration for businesses free?

Yes — TFN registration is completely free when done directly through the ATO. Avoid third-party sites that charge unless they offer professional tax or legal advice.

What documents are required to apply for a business TFN?

You'll need:

• Your ABN

• Business structure details

• Registered address and contact

• Director or trustee ID (driver’s licence, passport, etc.)

How do I retrieve a lost TFN?

Check ATO notices or myGov/ATO Online, or contact the ATO after identity verification.

How long does a business TFN take?

Companies/trusts/partnerships: up to 28 days. Individuals are often faster.

Can a non-resident director/company get a TFN?

Yes, subject to eligibility and identity verification. Seek advice for cross-border setups.

Where do I find my TFN on ATO letters/online?

It appears on ATO correspondence and in ATO Online under your entity profile.