You have done the hard part. You have read the quotes, picked an installer, and now they have asked for a deposit before they will lock in your job. And there it is, that small knot in your stomach: how much is fair, what happens if it all goes sideways, and are you about to hand money to someone you have known for all of three phone calls?
I have spent twenty years on the business side of solar, in supply, sales and the back office, watching how install companies actually run. So I want to walk you through this from both sides of the table. Once you understand why a deposit exists and what your rights are, you can pay one with confidence instead of crossing your fingers.
Why an installer asks for a deposit in the first place
A deposit is not a money grab. For a legitimate installer it does three jobs.
First, it pays for materials. The moment you sign, a good installer is ordering your panels, inverter and racking, often from a wholesaler who wants paying well before your system is on the roof. Panel and inverter prices move, and stock on the model you were quoted is not guaranteed forever. The deposit funds that procurement.
Second, it locks in scheduling. A confirmed job with money behind it gets a real spot in the calendar. A verbal “yeah, go ahead” does not, because operators have been burned too many times by customers who say yes and then vanish.
Third, it filters out the tyre-kickers. Plenty of people collect three quotes and keep shopping forever. A reasonable deposit signals you are serious, and that is fair enough.
Here is the part most homeowners never see: for a smaller install business, that deposit is genuinely funding the materials for your job. Solar runs on tight cash flow. The Small-scale Technology Certificates (STCs) that knock thousands off your price are tradeable certificates the installer or retailer usually claims on your behalf, and they do not convert to cash in the installer’s account until well after the panels are generating. Under the Renewable Energy Target, those certificates are created from your system’s deemed generation and bought by liable electricity retailers, not paid out as a government cheque (Clean Energy Regulator, n.d.). So the discount feels like a rebate to you, but the installer is often carrying that cost until the certificates clear. A modest deposit bridges that gap. That is legitimate, and understanding it helps you negotiate from a position of knowledge rather than suspicion.
What a fair deposit actually looks like
Across the Australian market, a deposit in the range of roughly 10 to 20 per cent of the total job value is normal and reasonable. On a typical residential system, that is a few hundred to a couple of thousand dollars.
Anything north of 30 per cent should make you ask questions. A demand for 50 per cent or more upfront, or worse, the full amount before a single bracket touches your roof, is a serious red flag. There is almost no legitimate reason a solvent installer needs the whole job paid before the work is done. When someone wants all your money first, the most common explanations are cash flow problems or worse, and neither is your problem to fund.
Retailers signed up to the New Energy Tech Consumer Code agree to additional consumer protections, including limits on what they can ask for upfront and clear disclosure of your cooling-off rights (New Energy Tech Consumer Code, n.d.; Volt Solar, n.d.). Choosing a code-signatory retailer is one of the simplest ways to know the deposit you are being asked for sits inside an agreed industry standard rather than whatever the salesperson felt like typing into the contract.
Your rights under Australian Consumer Law
This is where a lot of homeowners are protected more than they realise.
If you signed up in your own home, at a shopping centre stand, or after an unsolicited phone call, that is an unsolicited consumer agreement under the Australian Consumer Law. These come with a cooling-off period of 10 business days, during which you can cancel the agreement and get your money back, including any deposit (Australian Competition and Consumer Commission, n.d.). The trader is not allowed to start supplying or accept payment for certain goods during that window for unsolicited sales above the threshold amount. If a door-knocker is pressuring you to pay a deposit on the spot and skip the paperwork, they are very likely doing the wrong thing.
If you went to a showroom, called the installer yourself, or signed online after seeking them out, that is not an unsolicited agreement, so the automatic 10-day cooling-off does not apply. Your protections then come from the contract itself and from the consumer guarantees in the ACL: services must be provided with due care and skill, and goods must be of acceptable quality and fit for purpose. Those guarantees cannot be signed away, no matter what the fine print says.
A “non-refundable” deposit is not automatically legal just because the contract calls it that. Under the ACL, a deposit must be a genuine pre-estimate of the trader’s costs if you back out, not a penalty designed to punish you. If an installer takes a large deposit, does nothing, and then refuses to return it when you cancel, that can be an unfair contract term. When that happens, your state or territory consumer affairs body and the ACCC are the places to go.
None of this is a substitute for reading your contract, but it is the floor you are standing on. No clause an installer writes can drop you below it.
Red flags worth walking away from
Some warning signs are loud enough that I would put the pen down.
A demand for full payment upfront, before any work, is the big one. So is a non-refundable deposit with no written conditions explaining what you actually get for it. Verbal-only commitments with no signed contract are another: if it is not written down, you have nothing to enforce. Cash-only deposits with no receipt and no paper trail should worry you, because that is exactly how money disappears.
Pressure is its own red flag. “This price is only good if you pay today” is a sales tactic, not a fact about solar. Panels and inverters are not concert tickets. A genuine installer will give you time to read the contract and check their accreditation.
On that last point: before you pay anything, confirm the installer is accredited. Accreditation moved from the Clean Energy Council to Solar Accreditation Australia in 2024, so you may search for “CEC accredited” and land on an SAA page (Clean Energy Council, n.d.). Either way, you can check an installer’s current status by name or accreditation number on the SAA tool (Solar Accreditation Australia, n.d.). An accredited installer is also a precondition for your system being eligible to create those STCs in the first place, so this check protects both your safety and your discount.
What the contract should spell out before you pay
A deposit is only as safe as the document around it. Before money changes hands, the contract should clearly state:
An itemised payment schedule. The deposit, any progress payment, and the final balance, each tied to a milestone. A clean structure is deposit on signing, balance on completion and commissioning, with nothing dramatic in between for a standard residential job.
Refund conditions. Exactly what happens to your deposit if you cancel, if they cancel, or if the job cannot proceed because the roof or switchboard will not pass.
An installation timeline. A realistic window for when the work will happen, not an open-ended “we will be in touch”.
The actual equipment. Make, model and quantity of panels and inverter, so a quote on premium gear cannot quietly become a budget swap on install day.
The accredited installer’s details. The name and accreditation of the person who will sign off your system, not just the salesperson’s business card.
If any of that is missing, ask for it in writing before you pay. An installer who runs a tidy business will have this ready, because the same paperwork that protects you also protects them in an audit.
Using a deposit to your advantage
A deposit is not only a risk to manage; it can work for you. Paying it is what locks your quoted price against the panel and inverter price rises that ripple through this industry whenever exchange rates move or a supply squeeze hits. If you have a quote you are happy with on equipment you actually want, a deposit on a properly written contract pins that deal down.
The trick is to commit without overcommitting. Pay a fair deposit on gear that is specified in writing, with a payment schedule that keeps the bulk of your money in your pocket until the system is on the roof and commissioned. That way you get the price certainty without carrying the risk of an installer who has most of your money and little reason to hurry.
The installer’s side, and where this is heading
If you are reading this as an installer rather than a homeowner, the lesson cuts the same way. Most deposit disputes are not about dishonesty; they are about workflow friction. A customer is not sure what their deposit bought, the schedule slipped and nobody told them, the contract terms lived in three different emails. That silence is what turns a paid deposit into a complaint instead of a five-star review. The same discipline matters once you are subcontracting work out and need clean handoffs, which I cover in more detail in speed to quote wins solar jobs.
This is the problem I am building CurrentFlow to solve. The idea is to give solar businesses one clear, auditable record of quote acceptance, deposit status and scheduled install date, so the customer always knows where their money sits and what happens next. It is the tool I wished I had every time I watched a good operator lose a referral over a deposit they had every right to take, simply because nobody kept the customer in the loop.
For now, whichever side of the deposit you are on, the rule is the same: get it in writing, keep it fair, and never let the paperwork lag behind the money.
References
Australian Competition and Consumer Commission. (n.d.). Unsolicited consumer agreements and cooling-off periods. Australian Competition and Consumer Commission.
Clean Energy Council. (n.d.). Installer accreditation. https://cleanenergycouncil.org.au/industry-programs/accreditation
Clean Energy Regulator. (n.d.). Create small-scale technology certificates. https://cer.gov.au/schemes/renewable-energy-target/small-scale-renewable-energy-scheme/small-scale-technology-certificates/create-small-scale-technology-certificates
New Energy Tech Consumer Code. (n.d.). Approved solar retailers. https://www.newenergytech.org.au/approved-solar-retailers
Solar Accreditation Australia. (n.d.). Check installer accreditation status. https://saaustralia.com.au/accreditation-status-check/
SolarQuotes. (n.d.). Get up to 3 solar quotes from trusted installers. https://www.solarquotes.com.au/
Volt Solar. (n.d.). NETCC explainer. https://voltsolar.com.au/netcc/
FAQ
Is a solar deposit refundable in Australia?
It depends on how and where you signed. If you agreed to the system through an unsolicited sale, such as a door-to-door visit or a cold call, you generally have a 10 business day cooling-off period under the Australian Consumer Law during which you can cancel and recover your deposit. If you sought the installer out yourself, the contract terms govern refunds, but a deposit must still reflect the trader’s genuine costs rather than act as a penalty, so a blanket “non-refundable” clause is not automatically enforceable.
What is a normal deposit amount for solar in Australia?
Roughly 10 to 20 per cent of the total job value is the usual range and is reasonable. It covers the installer’s materials and locks in your spot in the schedule. Anything above 30 per cent deserves questions, and a demand for full payment before the work starts is a strong reason to walk away.
Why do solar installers want a deposit before starting?
Mainly to fund materials and confirm the booking. Panels, inverters and racking are often ordered and paid for well before install day, and the STC discount that lowers your price does not reach the installer as cash until the certificates are created and sold. A modest deposit bridges that gap and signals you are a committed customer rather than a quote-shopper.
How do I protect myself when paying a solar deposit?
Get everything in writing first: an itemised payment schedule, refund conditions, an installation timeline, the exact equipment make and model, and the accredited installer’s details. Confirm the installer’s accreditation on the Solar Accreditation Australia tool before you pay, use a payment method that leaves a record, and never hand over a large deposit under time pressure.
Are STCs a government rebate that the deposit covers?
No. STCs are tradeable certificates created from your system’s deemed generation, which liable electricity retailers must buy and surrender under the Renewable Energy Target. You typically assign your right to create them to the installer in exchange for an upfront discount, which is why it feels like a rebate at the point of sale even though no government payment is involved.