Every installer knows what happens in the weeks before a rebate step: the phones ring, then the supply chain stretches, then the crews burn out. Next January has two steps at once, and that is why December 2026 deserves its own plan. This piece puts numbers on the pull-forward, and suggests how to schedule around it.
The two steps
On 1 January 2027, small-scale solar moves from a five-year to a four-year deeming period, and the Cheaper Home Batteries Program factor moves from 6.8 to 5.7 (then to 5.2 on 1 July 2027). Both are scheduled and public, so customers will hear about them from retailers, comparison sites and friends.
| Job | December 2026 | January 2027 | Difference at about $38.50 |
|---|---|---|---|
| 6.6 kW solar, zone 3 | 45 STCs | 36 STCs | 9 STCs, about $345 |
| 6.6 kW solar, zone 4 | 39 STCs | 31 STCs | 8 STCs, about $310 |
| 14 kWh battery | 95 STCs | 79 STCs | 16 STCs, about $615 |
| Solar plus 14 kWh battery, zone 3 | 140 STCs | 115 STCs | 25 STCs, about $960 |
These are real but modest numbers. A customer who is ready will pull the trigger, and one who is not will not be rushed by $345. The people who move are those already considering a system in the next few months.
Who the pull-forward helps and hurts
It helps the households who would have installed in the first quarter anyway and bring the date forward. It also pulls cash into your December. It hurts the January to March period, which will feel quiet by comparison, and it hurts anyone with a fixed crew size and a fixed order book who cannot say no to a rush of work.
We would expect the effect to be larger for batteries than for solar, because the dollar gap is bigger and the battery buyer is more likely to be tracking the program. The mid-scale change adds some counter-pull: commercial systems above 100 kW and up to 1 MW installed from 1 October 2026 create STCs with a fixed five-year deeming period, so those jobs do not face a January step. See mid-scale solar and STCs. That is a reason to keep commercial quoting alive through December rather than going all-in on residential.
Plan the calendar backwards
Work back from the 1 January cut-off for each job type. An install must be complete and the date must be genuine, so allow time for:
- Network applications and approvals. DNSP timelines vary, and they are the most common cause of a missed deadline
- Stock. Batteries and inverters can run tight when demand spikes
- Weather and holiday periods. Late December has fewer working days than you think
- Photos and paperwork on the day. An install on 31 December with missing evidence is a January problem
A practical rule is to stop accepting new December-dated promises in mid-November, unless the job is already in the pipeline. After that, offer an honest January date and a clear explanation of the difference in discount.
Honesty about the date
The risk with a rush is promising a date you cannot hit. If a customer signs on 10 December on the strength of a 2026 discount and the install slips to 5 January, the discount falls by $345 to $960 depending on the job. Decide in advance who carries that. Three options:
- The customer carries it, and the contract says so
- You carry it for slippage you control and the customer carries it for slippage you do not, such as network delays
- You carry it in full, as a sales decision, and price it accordingly
Option two is the fairest and the one we see work best.
From the desk: Put a one-line clause in every December contract: “The STC discount shown applies to an installation completed before 1 January 2027. If completion falls on or after that date, the discount will be recalculated using the rules in force on the installation date.” It reads as plain fair dealing, and it removes the argument.
Cash flow in a busy month
A rush stretches working capital. You buy stock and pay crews now, and certificates convert to cash only after you lodge and your trader settles. At 140 STCs a job and $38.50 a certificate, a solar and battery job holds about $5,390 of certificate value. Ten of those is more than $50,000 sitting in claims. Faster settlement matters here. Established partners with Energy Merchants settle in 24 hours, with the first claim taking 48 to 72 hours while we verify details, and the rate is locked on lodgement of a complete claim. See how long STC payment should take.
Whoever you use, make sure the claims are right first time. A rejection in the last week of December can sit over the holiday period.
What January looks like
The quiet quarter after a rush is predictable, and you can plan for it as well. Three moves help:
- Book January and February work early. Customers who miss December and decide to proceed anyway should be scheduled before they cool off. A short follow-up call in the first week of January converts better than a general email.
- Use the lull for compliance catch-up. Review every December job file against the evidence checklist while the details are fresh, and fix gaps before the claims are lodged.
- Lead with value, not the lost discount. Customers who missed the cut-off need a reason to proceed that is not the rebate. Bill savings, battery backup and the remaining discount (36 STCs on a standard zone 3 solar system, 79 on a 14 kWh battery) are all still real.
The deeming schedule keeps stepping down each January to 2030, so each year has its own December rush and January lull. The installers who treat it as a recurring rhythm, and build staffing and stock around it, are the ones who cope best with the cycle.
Crew and compliance fatigue
Rushed jobs are where evidence gets thin. The battery photo and evidence rules from 1 March 2026 are strict, and a tired crew on a seventh install in a week will miss a serial photo. Add a mandatory photo check before the crew leaves the site. Our battery submission guide is a good checklist for it.
Related answers
Customers will ask about the cut-off in plain words. Two short answers help: how the solar rebate drops on 1 January and selling STCs before deeming drops.
What to do next
- Count the jobs you can genuinely install before 1 January and cap December sales to that number
- Add the install-date clause above to every contract
- Check each quote in the STC calculator and battery STC calculator
- Review what changes in January
- See pricing for today’s rate and how it works for settlement
- Keep the scheme changes hub open for date checks