For most installers the answer comes down to one thing: are you registered for GST? This page gives the short, practical version for the person on the tools. For the longer look at the tax mechanics, see GST on STC sales. It is general information, not tax advice.
If you are registered for GST
Yes. When you sell STCs, GST generally applies on top of the price. At the time of writing STCs have been roughly $38 to $40, so on a 45 STC job you are looking at around $170 to $180 of GST on a sale of roughly $1,700 to $1,800. You report it in your BAS like any other GST on sales.
If you are not registered
No GST is charged. You still need an ABN to be paid. If your turnover is near the registration threshold, speak to your accountant, because crossing it changes your obligations, and certificate income counts towards turnover.
Who raises the invoice
Most STC traders use a recipient created tax invoice. That means the trader creates the invoice for the sale, on your behalf, once you have signed an agreement. You do not send an invoice for each batch. It saves time but only works if your details are right. Our RCTI, GST and ABN guide lists what you need.
The traps
- Wrong registration status held by the trader, so the GST treatment on the invoice is wrong.
- An out-of-date ABN, which can stop payment.
- Spending the GST, then facing a BAS you cannot cover.
From the desk: quoted rates are normally ex GST, so the rate you are quoted plus GST is what you will see on the RCTI. Check the terms so you are comparing like with like.
A simple example
A GST-registered installer sells 45 STCs at a rate of $38 ex GST. The sale is $1,710, GST is $171 and the RCTI total is $1,881. The $171 is not income. It goes into the next BAS, where it is offset against any GST you have paid on your own purchases. If you are unsure how that nets out, your accountant can set it up in a few minutes.
What this means for installers
Get the ABN and GST registration sorted once, sign the RCTI agreement and move on. See how it works for the settlement flow, start trading for onboarding, and recipient created tax invoice for STCs for the document itself.