Start with a decent garage
Whoever you use, these four things separate a garage worth going back to from one you'll regret. Ask about them up front — a good garage answers all four without blinking.
The quote is in writing, and the invoice matches it
No arriving to find the number has moved. If it genuinely needs to change, they come back to you first.
Nothing is done without your say-so
Work goes ahead on what you authorised, not on what they found while they were in there.
They advertise what they actually do
The service, and the price, are what was on the forecourt sign or the website.
There is somewhere to complain that isn't them
An independent route if it goes wrong, rather than arguing with the person who did the work.
The shortcut: an accredited garage has already agreed to all four
The Motor Ombudsman runs the Service and Repair Code, a Chartered Trading Standards Institute-approved code of practice. Signing up commits a garage to exactly the four things above, including the independent complaints route — so starting from their list means the checking is done for you.
A garage without the badge isn't automatically a bad garage. Accreditation is voluntary and it costs money to join, so plenty of good independents never bother — especially small ones trading on word of mouth. Treat it as a shortcut that saves you asking, not as a pass mark. Where there's no badge, ask the four questions below yourself and judge them on the answers.
What to ask before you book
Four questions, about a minute on the phone. The answers tell you more than any review page.
"Is the quote fixed, and can I have it in writing?"
Sets the number and gives you something to compare the invoice against.
"What's your hourly labour rate?"
Rates vary enormously between main dealers and independents for identical work. Worth knowing before, not after.
"Can I supply my own parts?"
Some garages will fit parts you have bought and charge you labour only. Many won't, because they can't warranty a part they didn't source. Ask rather than assume.
"Will you call me before doing anything extra?"
The answer should be an immediate yes. Any hesitation tells you what you need to know.
Six red flags
Any one of these on its own is worth a question. Two or more and it's worth another garage.
Won't put the quote in writing
A written quote before work starts is the single thing that protects you. If they won't write it down, there is nothing to hold them to.
Work you didn't agree to appears on the bill
They should ring you and get your agreement before doing anything beyond the quote. Extra items added while the car was in is the most common complaint in the trade.
Won't give you the old parts back
Ask before the work starts. A garage with nothing to hide will hand them over, and it is the simplest way to see the wear you paid to fix.
Diagnosis with no explanation
"It needs a new one" is not a diagnosis. You should be told what the symptom was, what test they did, and what it showed.
Pressure to decide immediately
Unless the fault is genuinely dangerous — and they should be able to say exactly why — you are entitled to take the car away and get a second opinion.
Cash only, no VAT receipt
No paper trail means no warranty claim, no comeback, and nothing to take to an ombudsman.