Pay a modest deposit to secure a surveyed job, and keep the balance until the system is commissioned and the paperwork matches the quote. The decision is the schedule: what is due when the equipment is ordered, what is due when it is on the wall, and what you hold until the F-gas record and warranty registration exist. A large payment before a survey is a payment for a guess. Stage amounts vary by firm. There is no national tariff.
The transfer goes out after the codes are on the page
Once the survey has fixed the model codes, the pipe run and the outdoor spot, a deposit is how the company orders your pair rather than a unit for someone else. As a 2026 illustration, householders often see a deposit in the low hundreds of pounds, or a slice of the quoted total, and they should treat anything close to the full price up front as a reason to slow down. Get the schedule in writing before you transfer money. It should name the indoor and outdoor codes, the price and what the deposit buys. A bank transfer to a named limited company that will also appear on the invoice is the ordinary path. Pressure to pay a personal account the same day is not.
What the middle payment is buying
A fair middle stage, if there is one, covers equipment delivered and the first fix: bracket, pipes, drain and electrics.
- Survey and written model codes before a large deposit.
- A stated balance on commissioning.
- F-gas record and warranty registration before you call it finished.
- The same company name on the quote, the invoice and the certificate.
The balance that waits for commissioning
The last stage covers commissioning. That is when the circuit is pressure tested, vacuumed and charged by an F-gas certified company, and when you find out the drain actually falls or the pump actually runs. Hold enough of the price that a missed certificate or a unit that does not match the quoted codes still matters to the firm. If the only money left is a token, you are relying on goodwill for the part of the job that proves the system works.
A chimney breast and a cancelled day
If the survey was wrong, or the wall turns out to be a chimney, the price can change. That change should be a written variation before work continues, not a surprise on the invoice. You can refuse a variation that is really the missing lines from a thin quote, and you should not be told the deposit is forfeit for asking. A cancelled install day because the part did not arrive is the company's problem to rebook. A cancelled day because you refused access, or because a freeholder who was never asked has now said no, is different. Sort consent before the deposit, using the Planning Portal conditions in England as the outdoor check, plus the lease where there is one.
Stop if the full price is due before anyone has visited
An order deposit is normal. The balance belongs with commissioning, when the quoted models are on the wall and the refrigerant work has a record. A surveyed quote should not need a large cash sum before the wall and the outdoor spot are agreed. Pay a company invoice for a survey if there is a fee. Do not fund the equipment before those are agreed. If a firm will not put the deposit, any stage payment, and the balance in writing, choose a firm that will. Include the model codes you were offered, so nobody takes a deposit against a vague kilowatt and arrives with a different code.
Frequently asked questions
What if they want cash before they will book the survey?
A surveyed quote should not need a large cash sum first. Pay a company invoice for a survey if there is a fee. Do not fund the equipment before the wall and the outdoor spot are agreed.
Is the deposit refundable if consent is refused?
It depends what you signed. Agree that point before you pay, especially in a flat or a listed building where the outdoor unit may never be allowed.
Core buying guides
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Sources and further reading
How this guide was prepared
This guide was written by the Local AC Installers Editorial Team. We compare official guidance, legislation and established consumer information, separate general information from project-specific advice, and show publication dates and sources. We do not accept installer accreditation claims at face value.