Check that the installer holds the relevant state or territory electrical licence, has appropriate insurance and, where needed for government incentives, is accredited under the current scheme. Compare written quotes covering panel and inverter models, system size, design, installation timeframe, approvals, grid connection, warranties and the total out-of-pocket cost, including any rebates or STCs. Ask who will perform the electrical work, what after-sales support is provided and how faults are handled. Verify the installer’s details and incentive requirements through official sources such as the Clean Energy Council and your state regulator, and consider an independent electrical opinion for complex installations.