STC Compliance Guide for Solar Installers 2026

Compliance in the STC scheme is mostly about being able to prove, years later, that a certificate you created was earned. The money is real, the regulator is paying attention, and a clean file is the cheapest protection you can build. This is a guide to what the Clean Energy Regulator (CER) expects of solar installers in 2026, framed as habits, not a legal reading. For legal advice, use the CER’s guidance and your own adviser.

The three things that get installers into trouble

1. Eligibility. The system or product did not qualify on the installation date.
2. Evidence. The photos, forms and serials do not support the claim.
3. Accuracy. The numbers claimed do not match the install: capacity, zone, date, panels.

Everything else is a version of one of those.

Accreditation and who may do the work

Solar installers need accreditation through Solar Accreditation Australia (SAA), and battery installers need the right accreditation for storage plus compliance with the relevant standards. The accredited person must be the one who installs, supervises or designs, according to the role, and must attend as the rules require. Check your own accreditation status and the status of anyone you subcontract to. The SAA accreditation answer and installer attendance rules explain the requirements.

Product eligibility on the day

Panels and inverters must be on the Clean Energy Council approved lists when the system is installed. Products are removed from the list, and a model that was fine at quote may be off the list at install. Record the check, with the date, in the job file. For batteries, confirm the CEC approval and VPP capability for the exact model code. See the battery STC list answer.

The evidence file

Every claim should support itself without you in the room. A good file contains:

• the signed assignment form and the owner’s identity details;
• geotagged photos of the array, inverter, labels, serials, board and meter;
• electrical compliance documentation;
• the DNSP approval, where applicable;
• the invoice, showing the STC discount;
• the installer’s declaration or written statement;
• a calculation sheet showing kW, zone and deeming year.

The photo requirements resource is the practical shot list. Battery labelling photos need geotags and timestamps from 1 March 2026, and the CER has reported using AI-assisted image analysis to find missing labels and metadata problems. See the battery photo checklist.

Audits and inspections

The CER selects installations for inspection and requests evidence for claims. An inspection might find a safety problem, a non-compliant product or a system that is smaller than claimed. The regulator reported high battery inspection volumes in early 2026 and has taken action against installers. How audits proceed is covered in how STC audits work and what to expect from a CER audit.

If a notice arrives:

1. Note the deadline and respond within it.
2. Pull the complete file, not a selection.
3. Tell your trader, because the agreement may require it.
4. Do not alter or backfill records.

Clawback

If certificates were created in error, the CER can require them to be surrendered or the value recovered. Where a trader has already paid you, the trader agreement typically allows the trader to recover the value from you. That makes clawback a cash-flow risk months after the job.

A worked example. An installer completes 30 solar jobs in a month at 45 STCs each. At $38 that is $51,300 of certificates. If a systematic error, such as the wrong zone, affects all of them, the installer may have to repay the difference on every job. In zone 4, using zone 3’s rating overclaims 6.6 x (1.382 - 1.185) x 5 = 6.5 STCs per job, so about 6 STCs, roughly $230 each at $38, or about $6,900 across the month, plus any penalties and the cost of correction.

The 2026 changes that matter

• Deeming period. Five years for 2026 installs, four for 2027. A job that slips across 31 December changes the count.
• Battery evidence. New photo rules from 1 March 2026.
• Mid-scale solar. Systems above 100 kW up to 1 MW installed from 1 October 2026 can create STCs with a fixed five-year deeming period. Applications open mid to late November 2026, so keep records of installations in the interim. See mid-scale solar STCs.
• Battery tiers. The factor and tiers apply by installation date. See the tier explainer.

A monthly compliance routine

1. Sample five claims and check each against its photos, form and calculation.
2. Check your accreditation and the accreditation of every installer on your team.
3. Review rejections from the month and write down the cause of each. The top rejection reasons will help you categorise them.
4. Refresh the checklists if rules changed.
5. Check trader terms, especially clawback and rejected claim provisions.
6. Back up your files in a system that holds metadata.

Choosing a trader with compliance in mind

A trader’s desk should pre-check evidence before lodgement and tell you what is wrong while you can still fix it. The terms on rejected claims and clawback matter as much as the rate. Our checklist for choosing a trader and the STC clawback answer cover the questions to ask. Energy Merchants runs a compliance desk review on every claim, which catches the problems this guide describes.

Subcontractors, sales partners and who is on the hook

A growing share of residential and commercial work runs through subcontractors and sales partners. The scheme does not care who sold the job. It cares who installed it, who certified it and who lodged the claim.

• Subcontracted installers must hold the right accreditation for the role they perform. Check it on the register, not just on their word, and keep a copy in your records.
• Sales partners who promise customers “free” systems or inflated discounts create risk for the installer whose name is on the paperwork. Review every sales claim about STCs before it reaches a customer.
• Third-party lodgement through an agent does not move the responsibility for the evidence. The installer still holds the photos, forms and records.

How long to keep records

The CER’s guidance sets the requirement, and installers commonly keep claim files for several years, longer where a dispute or an audit is open. A practical rule is to keep the complete file for as long as the longest period the regulator or your trader contract could ask about, and to store it somewhere that preserves photo metadata. When you leave one trader for another, download your history first. See the switching guide and the SAA accreditation answer.

What to do next

1. Run the monthly routine this week and write down what you find.
2. Fix the first-visit photo and label routine, then check it on the next three jobs.
3. Read the STC scheme guide for installers for the wider picture.
4. When you want claims pre-checked, see how it works and start trading.