The step from 5 years to 4 is the biggest scheduled change to small-scale solar incentives since the scheme began its decline. It arrives on 1 January 2027, and it applies by installation date.
The 2027 table
The formula is kW x zone rating x 4, rounded down.
| System | Zone 1 | Zone 2 | Zone 3 | Zone 4 |
|---|---|---|---|---|
| 6.6 kW | 42 | 40 | 36 | 31 |
| 10 kW | 64 | 61 | 55 | 47 |
Compared with 2026, a 6.6 kW zone 3 system loses 9 certificates. At about $38, that is roughly $340 less discount on the same system. Larger systems lose more.
Batteries too
The battery STC factor drops on the same date, from 6.8 to 5.7 per kWh of usable capacity. A 10 kWh battery moves from about 68 certificates to about 57. Customers who are on the fence about a combined solar and battery install have a real incentive to complete before the end of December. The battery pillar explains the program.
The planning problem
Pipeline jobs that look like they will complete in December need a hard date. Supply delays, switchboard upgrades and distributor approvals can push an install into January. Decide in advance who carries the cost when that happens: you or the customer. Put it in the contract.
What this means for installers
Plan your Q4 rush around ready-to-go jobs, and make sure photo sets and forms are complete so claims clear quickly. For more detail, read what changes in January, the deeming period and zone ratings guide and today’s rate on the pricing page.
Prices move, so treat any number here as a snapshot and check the live figure before you quote a job.
Remember that the step continues: the deeming period falls to 3, 2 and 1 years in following years, with the scheme ending on 31 December 2030. Any long term sales plan should assume a shrinking certificate component and lean on service quality and the battery market instead.
For installers, the practical message is to be transparent. Customers dislike surprises more than they dislike bad news, and a quote that clearly states the 2027 certificate count up front will not be a source of dispute at invoice time. Update your templates before the end of the year so the new numbers appear automatically.