For a solar installer, STC trading is not a side task, it is a working-capital decision. Each completed job leaves you holding a certificate entitlement worth roughly $1,700 on a typical 6.6 kW system, and until that entitlement turns into cash you are funding a customer’s discount out of your own pocket. How you handle that cycle decides how much you can grow without a bigger overdraft.
This guide treats certificate trading as a business function with an owner, a routine and a number to watch. It assumes you know the basics and want to run the function well. If you need the foundations, start with what an STC is and how the scheme works for installers.
Decision 1: do it yourself or use a partner
You have two structures. As a registered person you create certificates in the REC Registry under your own account and then sell them. As a client of a registered agent, the agent creates the certificates, checks the claim and pays you.
| Registered person | Agent or trader partner | |
|---|---|---|
| Set-up | Regulator identity verification, can take weeks | Account sign-up, first claim 48 to 72 hours with us |
| Admin | Yours: registry, lodgement, queries | Shared: partner creates and pre-checks |
| Sale | You find a buyer or use the clearing house | Partner pays you at its rate |
| Control | Full | Less, but with support |
For most crews under a few hundred jobs a year the partner route costs less in time than the small saving from doing it all yourself. For larger operators with dedicated back-office staff, selling direct can make sense.
Decision 2: how you want to be paid
Settlement terms are the lever. Typical offers range from a one-day payment to ten business days or “when the registry clears”. Work out what the gap costs. At 30 jobs a month, each with 45 STCs at $38, the monthly value is $51,300. On ten-day terms you carry on average about $25,000. On 24-hour terms you carry about $1,700 a day, so a day or two of volume. If your overdraft costs 11 per cent a year, $25,000 costs around $230 a month, which is more than most rate differences between traders. See how long STC payment should take.
Decision 3: price risk
If your sales team quotes a certificate price at the time of contract, and the rate you actually receive is set when the claim is lodged weeks later, you are carrying price risk. Three ways to handle it:
- Quote conservatively. Use a figure a little below spot.
- Lock at lodgement. Choose a buyer that fixes your rate when a complete claim is lodged.
- Use the clearing house floor. Treat $40 ex GST as the ceiling, not the quote.
At the time of writing spot has sat at roughly $38 to $40, so the downside is modest, but the structural risk is real as deeming years fall and supply patterns shift. For more on the market, see STC trading explained.
Decision 4: what you do about volume
Volume matters in two ways. Traders with scale can offer better rates to partners who send consistent volume, and a Partner Program can add priority settlement and a named account manager as you grow. Ask any trader what changes at 50, 150 and 400 certificates a month, and get it in writing. Our Partner Program page sets out the three tiers. Do not assume the rate on day one is the best you can negotiate; do not assume it is not.
The monthly review
Once a month, spend 30 minutes with these questions:
- How many jobs were installed, claimed and paid?
- What is the average days to cash?
- How many claims were rejected or queried, and why?
- What is the net rate per STC after any fees?
- What is the oldest unclaimed job, and how many months of the 12-month window remain?
Write the answers in one place. After three months you will see a trend, and the trend will tell you whether you need a better process, a better partner or both.
Protect the business from the downside
The regulator audits installations, and certificates can be cancelled. Read what your agreement says about who bears the loss, how disputes are handled and whether you must repay. Our guide to how audits work shows the process, and the answer on STC clawback explains the exposure. A pre-check desk reduces the risk before a claim goes in, which is the cheapest place to fix it.
Looking ahead to 2027
On 1 January 2027 the deeming period drops to four years, and a 6.6 kW zone 3 job falls from 45 to 36 STCs. Battery STC factors fall from 6.8 to 5.7 per kWh. Customers may rush to install in December; your cash cycle will feel it first. Read the January 2027 changes and plan crew and cash for a December peak followed by a January lull.
Three installer profiles
The two-crew business. Around 15 to 25 jobs a month, owner-run, one part-time admin. The priority is cash predictability. A single partner with next-day settlement and a pre-check removes most of the admin and nearly all of the cash-timing risk. Rate matters, but not as much as the number of days between install and bank.
The growing regional operator. Perhaps 60 jobs a month across several postcodes and zones. Here the zone mix matters: a zone 1 job earns about 17 per cent more STCs than zone 3 for the same system, so a regional footprint changes the average certificate value. Volume tiers start to be worth negotiating, and a named account manager saves hours a week.
The solar-plus-battery specialist. Batteries add a second certificate stream with its own rules and a higher dollar value per job. A 14 kWh battery earns about 95 STCs in 2026, around $3,600 to $3,800, so the cash tied up per job can double. Rejected battery claims are costly, so a pre-check on battery evidence is worth more here than a few cents on the rate. See battery STCs and the Cheaper Home Batteries Program.
Questions to put to any buyer
- What is your rate today, and when exactly is it locked for me?
- How many days from a complete claim to cash in my account?
- What fees of any kind apply, now or later?
- Who reviews my claim before it goes to the regulator?
- What happens if certificates are cancelled after payment?
- Who is my contact, and will I get the same person next month?
- What changes for me as my volume grows?
A buyer who answers all seven plainly is worth talking to. One who answers three and changes the subject is telling you something.
What to do next
Read the STC trading pillar and the how it works page for the end-to-end path. Compare against today’s rate card, then start trading or talk to the desk about moving across from your current buyer. The answer on selling STCs as an installer covers the quick version.