GST on quotes: what Australian tradies need to know

GST trips up a lot of new tradies, mostly on small things: a quote that adds GST at the end as a surprise, a GST line on a quote from someone who isn't registered, or a quote sent where a tax invoice was needed. Here's how to get it right.

This guide is general information, not tax advice. Check the ATO and your accountant for your situation.

For GST on deposits and progress claims (each one is its own taxable supply), read GST on quotes, deposits and progress claims.

Are you registered for GST?

Everything else depends on this.

• You must register once your GST turnover reaches $75,000 a year (or you expect it to).
• You can register voluntarily below that.
• If you're not registered, you don't charge GST, you don't show GST, and you don't claim GST credits on your purchases.

Plenty of tradies starting out are below the threshold. That's fine; just make sure your quotes match.

If you're registered: quote including GST

When you quote a consumer (a homeowner, a tenant, anyone buying for personal use), the price they see should be the total they'll pay. The ACCC expects businesses to display a single total price including GST and any unavoidable charges (ACCC: price displays).

In practice:

• Price your lines however you like (many tradies work ex GST internally).
• Show the total including GST clearly.
• Show the GST amount as its own line. It's good practice and saves a phone call.

A worked example

GST is 10% of the ex GST price, which is the same as one eleventh of the GST-inclusive total. $2,365 divided by 11 is $215.

Optional extras and GST

If you offer optional extras, the total should update to include GST on whatever the customer picks. Extras they haven't chosen don't need to be in the total, but the total for what they have chosen must be clear (ACCC: optional extras and the total price).

If you're not registered: no GST anywhere

If you're not registered:

• Don't add 10% to your price.
• Don't show a GST line, even as "$0".
• Don't call your invoice a "tax invoice".

It's worth saying "Not registered for GST" in small print so business customers don't chase you for a tax invoice they can't get.

Business customers and ex GST quotes

Builders, property managers and other businesses usually think ex GST, because they claim the GST back. Quoting them ex GST is common, but label it clearly ("$2,150 + GST") so nobody misreads the total.

Quotes are not tax invoices

A quote is an offer. When the job's done (or a payment is due), you issue an invoice. If you're registered for GST, that should be a tax invoice.

According to the ATO:

• Your customer needs a tax invoice to claim a GST credit on a purchase over $82.50 including GST.
• If they ask for one, you must provide it within 28 days.
• A tax invoice for $1,000 or more must also show the buyer's identity or ABN.
• It must include things like "Tax invoice", your identity and ABN, the date, a description of what was sold, and the GST (or a statement that the total includes GST).

Deposits count too. If you take a deposit and the customer is a business, they may ask for a tax invoice for it.

GST and card fees

Card surcharges on Visa, Mastercard, eftpos and American Express are banned from 1 October 2026 (RBA announcement), so the cost of card payments now belongs inside your price. See the card surcharge ban guide.

Common GST mistakes on quotes

Adding GST at the end as a surprise. A customer who agreed to "$5,000" and then sees "$5,500 including GST" on the invoice feels tricked. If the price is for a consumer, the number you quote should already include GST.

Showing GST when you're not registered. It looks like you're collecting tax you won't pass on. Remove the line entirely.

Mixing ex GST and inc GST lines. Pick one basis for the lines (most tradies use ex GST) and show the GST once, at the bottom, with the total including GST.

Rounding the GST on every line. Small rounding differences add up and make the total look wrong. Work out GST on the subtotal.

Forgetting GST on optional extras. If a customer ticks an extra, the total including GST should go up by the extra plus its GST.

Treating a deposit as GST-free. A deposit is part payment for a taxable job. If a business customer asks, they may need a tax invoice for it.

Registering partway through the year

If you cross the $75,000 threshold partway through the year, you need to register and start charging GST from your registration date. Quotes you sent before you registered may not include GST. Talk to your accountant about how to handle jobs that span the change, and update your quotes straight away so new ones are right.

Quick checklist

• Know whether you're registered, and set your quotes up to match
• Registered: show the total including GST and the GST amount
• Not registered: no GST anywhere, say so in small print
• Business customers: ex GST is fine if it's clearly labelled
• Issue a proper tax invoice for the sale, not just the quote

Karven handles GST either way: tell it once whether you're registered, and every quote shows the right total, with or without a GST line.

This guide is general information, not tax advice. Check the ATO and your accountant.