STC zones and zone ratings by postcode

The four zones and their ratings

The zones and ratings come from a federal instrument, in force since 1 January 2020, that puts every Australian postcode range into one of four zones by the solar output expected there. The rating is the megawatt hours the instrument deems each kilowatt of panels to generate in a year. One STC is one megawatt hour, so the sum for a panel system is kW x zone rating x deeming years, rounded down to a whole certificate.

The deeming years are 5 for a system installed in 2026, and they fall by one each January until the scheme ends with 2030. The deeming period covers that side of the sum.

What a zone does to a job

The same panels earn a different number of certificates in each zone. For systems installed in 2026, at $41 per STC:

$41 per STC is what we pay on a home system as at 3 November 2026. That is above the $40 clearing house price, and the regulator advises caution with prices above that cap, so check us as you would any trader. What to check in any trader.

Between zone 1 and zone 4 the gap on a 10 kW system is 22 STCs, or $902. Between zone 3 and zone 4, where most of the population lives, it is 10 STCs, or $410, on the same panels. Work out your own job.

The capital cities

A suburb takes the zone of its own postcode, and in most of a capital that is the zone of the centre. Not always: Melbourne's northern suburbs of Craigieburn (3064), Epping (3076) and Broadmeadows (3047) are zone 3, 3 and 3 while the city centre is zone 4, and north of Perth, Two Rocks (6044) is zone 2 against zone 3 in the city.

Zones do not follow state lines

The boundaries follow postcodes, so a state can hold three or four zones, and a regional city can sit in a different zone from its capital. The zones each state's delivery postcodes fall in, read off the same table:

Some places that show where the lines fall:

So Ballarat (3350) and Bendigo (3550) are zone 3 and 3 while Melbourne is zone 4, Albany (6330) and Esperance (6450) are zone 4 and 4 while Perth is zone 3, and Cooma (2630) is zone 4 in a state whose capital is zone 3. Quote from the postcode, not the map in your head.

Every postcode range and its zone

The full table, in postcode order. Find the range that holds the install postcode. We copied it from section 6 of the instrument, and every build of this site checks that it covers 0000 to 9999 with no gaps or overlaps.

Hot water uses a different map

Solar water heaters and air source heat pumps have their own zone map, and their certificates are set per model from the regulator's register rather than from kilowatts. This page and our calculator cover panels only. STCs for heat pumps and solar hot water explains the hot water zones and shows where they differ from the panel zones.

Find your zone

Our STC calculator looks the zone up from the install postcode and works out panels and battery together, for any install date to 2030. Each state page starts the calculator in its capital and lists the paperwork that state needs:

• Sell STCs in New South Wales
• Sell STCs in Victoria
• Sell STCs in Queensland
• Sell STCs in South Australia
• Sell STCs in Western Australia
• Sell STCs in Tasmania
• Sell STCs in the ACT
• Sell STCs in Northern Territory