GST Registration in Australia: The $75,000 Threshold and the 21-Day Rule

📊 What is the $75,000 threshold?🔗

The GST registration threshold is $75,000 in GST turnover for most businesses, $150,000 for non-profits. Two types of businesses must register regardless of turnover: taxi, limousine and ride-sourcing operators, before their first trip, and fuel tax credit claimants, as soon as they want to claim. None of this applies until your activity actually counts as a business in the ATO's eyes, worth confirming that first if you're not sure.

🧮 How GST turnover is actually calculated🔗

"GST turnover" is gross business income, not profit. Start with total gross income, then subtract GST already included in prices, input-taxed sales, and sales not connected with an enterprise you run or with Australia. Once you're registered, you'll need to add 10% GST to your invoices, our GST calculator does the maths for you, including working the tax back out of a GST-inclusive price.

🎯 The essential: Even if your current GST turnover is at or above $75,000, you don't have to register if your projected turnover will stay below the threshold. Both tests matter, and you need to run them monthly if you're not yet registered.

⏳ The 21-day rule🔗

Once you know, or reasonably should know, that either test hits $75,000, you have 21 days to register. The clock starts the moment you identify the threshold is reached or will be reached, not at the end of the financial year. Register online via ATO Online Services for Business, by phone on 13 28 66, or through a registered tax or BAS agent. You'll need an ABN first.

⚠️ What happens if you register late🔗

Failing to register when required is a 20 penalty unit fine, currently in the thousands of dollars and rising over time as penalty unit values are periodically indexed, check the ATO's current penalty unit schedule for the exact figure. On top of that, the ATO can require you to pay GST on every taxable sale made from the date you should have registered, even if you never charged customers GST, coming straight out of your margin, and it can apply the General Interest Charge on unpaid amounts, which compounds daily and is no longer tax-deductible. Backdating is generally capped at 4 years unless fraud or evasion is involved.

🙋 Voluntary registration below $75,000🔗

Any business can register voluntarily. It tends to make sense if you have significant GST-inclusive business expenses, since registering lets you claim input tax credits back, or if your clients are mostly other businesses who can claim back the GST you charge them, so it doesn't cost them anything extra. Registering early is also worth it if you're planning to grow past $75,000 soon, your systems and processes are already set up when you hit the mandatory threshold. If you're reselling items online rather than running a broader business, our guide on tax on selling stuff online covers exactly when this threshold starts to matter for you. Content creators need to watch this one too, AdSense and other overseas platform payments still count toward your $75,000 even though they're generally GST-free exports, as explained in our YouTube, Twitch and Patreon income tax guide. Affiliate marketers face a similar nuance: commissions from overseas networks are generally not something you charge GST on yourself, since you're not the merchant making the sale, but the GST treatment of specific commission structures is genuinely case-by-case, our affiliate marketing tax guide covers it alongside the separate reseller/dropshipper GST rules. Etsy sellers face a similar creeping-toward-the-threshold problem as their shop grows from a few listings into a proper store, our Etsy seller tax guide walks through exactly what changes once you're registered. The same creep applies to AI side hustlers selling digital products or freelance services, our AI side hustle tax guide covers how that income is taxed before you even get near this threshold.

The trade-off: you must charge GST on all your sales, not pick and choose, and you need to lodge a BAS regularly. If your clients are mostly consumers who can't claim GST back, or your expenses are low, the admin overhead may not be worth it.

❓ Frequently asked questions🔗