STC trading is how the certificates your crew creates turn into cash. The scheme part, where certificates are created, is regulated and fixed. The trading part is a market, and the difference between a good and a poor trading arrangement on a book of 80 jobs a month can be a five-figure sum a year in rate, plus a lot more in cash flow.
This guide is for installers who want to understand the market well enough to compare offers. It is not about picking us. A good trader should hold up to the questions below.
The market in one paragraph
Certificates are traded in two places. The Clean Energy Regulator’s STC Clearing House buys certificates at a fixed $40 (ex GST) but processes slowly. The spot market is where traders buy and sell at a price that has been roughly $38 to $40 in 2026, close to the ceiling because the clearing house acts as a backstop. An installer selling to a trader gets a rate slightly below spot, which pays for the trader’s risk, capital and service. How much below, and how fast the money arrives, is the contest.
Rate is only half the offer
Two offers on 60 STCs a job:
| Trader A | Trader B | |
|---|---|---|
| Headline rate | $38.40 | $38.00 |
| Fees | $0.30 per certificate admin | None |
| Net per STC | $38.10 | $38.00 |
| Settlement | 20 business days | 24 hours (established partner) |
| Cash tied up on 80 jobs (4,800 STCs) | about $182,900 for four weeks | about $182,400 for one day |
Trader A looks $0.40 better per STC, which is $1,920 across 4,800 certificates. But on 80 jobs a month you would carry roughly $182,000 for twenty working days. At a business overdraft rate of 10% that capital costs about $1,400 a month, so most of the headline gain is gone, and you take on counterparty exposure for four weeks. The rate that matters is the net rate after fees and financing, over the time the money is outstanding. See installer cash flow for the model.
The kinds of buyer
- Registered agents and traders. Buy certificates directly, set a daily rate, pay on a stated term. The most common route.
- Platforms and aggregators. Software that handles registry lodgement and pairs you with buyers. Some charge subscription or per-claim fees.
- The clearing house. No counterparty risk, but slow and not a pricing contest.
- Retailers and installers with in-house trading. At volume, some businesses build their own desk. It rarely makes sense below several thousand certificates a month.
Greenbot was permanently suspended as a registered agent in 2024, and its clients moved mainly to Formbay and One Stop Warehouse. That episode is the best argument for checking who holds your money and for how long. See what to do if a trader goes under.
What to ask any trader
- Is the rate published, and when is it locked? The rate should be fixed on lodgement of a complete claim, not on payment.
- What is deducted? Fees, registry costs, volume penalties, chargebacks.
- When does the settlement clock start? On lodgement, on validation or on “approval”?
- What happens to a rejected claim? Who bears the loss, and when?
- Can you hold a rate for a larger sale? Some traders do forward deals for bigger volumes.
- Who is on the phone? A named account manager or a ticket queue.
The contract terms checklist and choosing a trader checklist expand on each.
Spot, forward and “price locks”
Most installers sell at the day’s rate. Larger operators sometimes agree a rate for a month or a quarter. If STCs sit at the $40 ceiling, forward pricing gains little. If the market looks soft, a locked rate protects margin. Either way, the lock should be in writing and should say what volume it covers.
For context, a 6.6 kW system in zone 3 in 2026 creates 45 STCs, worth about $1,710 at $38. In 2027 the deeming period drops to four years and the same system creates 36. Volume and rate are both worth watching. See the deeming period guide.
Tax, GST and paperwork
Selling STCs is a taxable supply, and traders typically issue a recipient-created tax invoice (RCTI) on your behalf, which requires an ABN and a GST registration decision. The RCTI, GST and ABN resource covers it. Keep assignment forms for the period the CER expects, and keep photos too.
Batteries and mid-scale change the numbers
A battery claim runs 90 to 175 STCs, so one battery equals two or three solar jobs in value. Settlement time matters more when a single claim is $3,500 or more. From 1 October 2026, mid-scale solar above 100 kW up to 1 MW also creates STCs: a 250 kW system in zone 3 creates about 1,727 STCs, over $65,000 at $38 on one claim. Ask any trader whether they have handled claims of that size and what their pre-checks look like. The pillar page is mid-scale solar STCs.
Red flags
- Rates that are not published or change after lodgement.
- A trader that asks for payment to hold a rate.
- Contracts that let the trader reduce the price for “market movement” after lodgement.
- No named person to call.
- Settlement promises that depend on “approval” with no deadline.
Our guide to spotting STC scams covers more.
Running a quarterly review of your trader
Trading arrangements drift. Rates move, terms creep and your own job mix changes, so a ten-minute check each quarter keeps the arrangement honest.
- Pull the statements. Add up certificates sold, gross dollars, deductions and net dollars for the quarter.
- Compute the net rate per STC. Net dollars divided by certificates. Compare it with the spot range for the period.
- Measure days to cash. For ten random claims, count the days from lodgement to money.
- Count rejections. How many claims bounced, why, and who carried the cost?
- Re-quote the market. Ask one other trader for terms on your actual mix. You do not have to move, but you will know where you stand.
On a book of 2,250 STCs a month, a drift of 30 cents a certificate is $675 a month, or $8,100 a year. That is more than the cost of an hour a quarter. A price the market sets is one thing, but a rate that slips from your agreed terms is another, and the second is the one a review catches. See also the STC price answer and trading price versus the clearing house.
What to do next
- List your last three months of certificate volume, split solar, battery and hot water.
- Ask two traders for written terms, then calculate net cash per STC and cost of carry.
- Check the daily rate on the pricing page and how settlement works on how it works.
- See STC trading for the overview, or start trading to lodge a first claim.