Eligibility is a set of checks, and a claim should only be lodged when all of them pass. This page is the installer’s checklist. For the household version, see is my solar system eligible for STCs.
The checks
| Check | What to confirm |
|---|---|
| Size | 100 kW or under, and under 250 MWh a year (above 100 kW up to 1 MW from 1 October 2026 under the mid-scale rules) |
| Panels | New and on the approved list at install |
| Inverter | New and on the approved list at install |
| Installer | Current SAA accreditation and electrical licence |
| Standards | Installed to the relevant Australian standards |
| Owner | Signed assignment before the claim |
| Evidence | Photos, serial numbers and certificates match the claim |
| Timing | Claim lodged within the allowed window |
Above the limit
If the system is above 100 kW, or generates more than 250 MWh, it falls outside the small-scale test. From 1 October 2026, solar up to 1 MW can still create STCs with a fixed five-year deeming period; see mid-scale solar STCs and the 100 kW limit for what happens next.
Deeming and zone
For eligible systems, the STC count is the capacity times the zone rating times the deeming years, rounded down. The zone ratings are 1.622, 1.536, 1.382 and 1.185, and the 2026 deeming period is five years. Our deeming period and zone ratings guide has the postcodes.
Where claims are lost
- Products that dropped off the approved list before installation.
- Serial numbers that do not match those registered.
- Photos that do not prove the installed equipment.
- An accredited installer who did not supervise or sign off.
See the top rejection reasons and the photo requirements guide.
From the desk: screenshot the approved product listing on the install day and file it with the job. If a question comes up later, you can show the status at the time.
Hybrid and off-grid systems
Off-grid and hybrid systems can be eligible too, provided the generation unit meets the same rules. The paperwork differs a little, because there is no network connection approval, but the equipment, accreditation and evidence rules still apply. Check what your claim needs before you quote, rather than after install.
What this means for installers
Make eligibility a pre-install gate, not a post-install clean-up. A trader with a compliance desk can add a second check before lodgement, which is worth having. See STC trading, how it works and the resources hub.