How Much GST Do I Charge as a Tradie in Australia?

GST trips up more Aussie tradies than just about anything else on the admin side. The rules themselves are actually simple — it is knowing when they kick in, and how to add GST without fat-fingering the maths, that catches people out. Here is the whole thing, start to finish.

What GST actually is

GST (Goods and Services Tax) is a flat 10% tax added to most goods and services sold in Australia. As a tradie, if you are registered, you collect that 10% from your customers on the ATO's behalf and then pass it on when you lodge your BAS (Business Activity Statement). You are essentially a collection agent for the tax office — the GST was never your money to keep.

The flip side: once you are registered, you can also claim back the GST you pay on business expenses (tools, materials, fuel, phone, that new ute). Those are called GST credits, and they can add up to real money.

When do you have to register?

You must register for GST when your business turnover reaches $75,000 or more in any rolling 12-month period — or when you expect it to. This is turnover (total sales), not profit. It is a common and expensive mistake to wait until the end of the financial year to check; the ATO expects you to register within 21 days of hitting the threshold.

• Under $75k: registering is optional. Some tradies register early to claim GST credits on big tool/vehicle purchases.
• $75k and over: registration is compulsory. Once registered you must charge 10% on all taxable sales.
• Taxi/rideshare aside: different rules apply there — not relevant to most trades.

How to add GST to a price

This is the bit people get wrong at 9pm doing quotes. Two simple rules cover almost every situation:

Adding GST to a price

Multiply your price by 1.1.

Finding the GST inside a total

Divide the GST-inclusive total by 11.

Showing GST on your invoices

Once registered, your invoices become tax invoices and must show a few things by law so your customers can claim their own GST credits:

• The words “Tax Invoice”
• Your business name and ABN
• The date
• A description of what you did
• The GST amount (or a note that the total includes GST)
• The total price

For any invoice of $1,000 or more you also need the buyer's identity or ABN. Get in the habit early — a tidy tax invoice is what keeps the ATO and your accountant off your back.

Common GST mistakes tradies make

• Spending the GST. That 10% is not yours. Park it in a separate account so BAS time is not a heart attack.
• Registering late. Blow past $75k and forget to register, and you can end up owing GST you never charged.
• Forgetting to add it to quotes. If you quote $5,000 and later realise it should have been $5,000 + GST, you either eat the $500 or have an awkward chat.
• Not claiming credits. Registered tradies leave money on the table by not claiming GST back on expenses.