The short answer, and where it comes from
No. A good independent garage can service your car, and the manufacturer's warranty stays in force. What matters is how the service is done, not who does it.
That freedom comes from competition law, not from your warranty booklet.
The Competition and Markets Authority publishes guidance on motor vehicle agreements, and paragraphs 5.35 to 5.41 cover warranties. The Chapter I prohibition is the Competition Act 1998's ban on anti-competitive agreements.
A servicing restriction is likely to be caught by it, the CMA says at paragraph 5.36. The restriction is this. A warranty made conditional on the owner having "repair and maintenance work that is not covered by warranty carried out only by members of the Authorised Network".
Read that qualifier twice. It's work the warranty isn't paying for: your ordinary, out-of-your-own-pocket servicing. That's the bit a manufacturer can't tie to its own network.
Plenty of what's written about this says the rule comes from an EU regulation retained after Brexit. That stopped being true in 2023. The government's own explanatory memorandum records that the retained Motor Vehicle Block Exemption Regulation "expires at the end of 31st May 2023".
The UK wrote its own replacement, the Competition Act 1998 (Motor Vehicle Agreements Block Exemption) (No. 2) Order 2023. It came into force on 1 June 2023 and runs until the end of 31 May 2029.
One more piece of precision, because it changes what you can argue. The Order itself never mentions warranties. What it does is protect independent garages' access to spare parts, tools, technical information and training. The warranty position lives in the CMA's guidance on the Chapter I prohibition, which is guidance rather than statute.
What the manufacturer can still insist on
Your warranty is a contract. Under section 30 of the Consumer Rights Act 2015, a guarantee "takes effect, at the time the goods are delivered, as a contractual obligation owed by the guarantor". So its own conditions bind you, and they're the ones people actually fall foul of.
Take Kia's published 7-year warranty terms as a worked example. Its basic warranty counts one thing as lack-of-maintenance damage: servicing that isn't completed within the time and mileage recommendations in the service book and the owner's manual.
It also excludes "improper maintenance or the use of fuel, oil or lubricants, additives other than those we recommend". And it tells owners to keep their records and receipts.
Notice what isn't in there. Nothing in those basic-warranty conditions says a routine service has to happen at a Kia dealer. They're about the schedule, the fluids and the paperwork.
One caveat, and it's worth reading your own booklet for. Kia's anti-perforation warranty is a separate warranty, covering rust holes in the body panels. That one does carry a location condition: the car "should be inspected by a Kia dealer or authorised repairer every 12 or 24 months depending upon the model".
Different warranty, different rules, same document.
So the three things to get right are:
- Timing. Service on or before the interval, by date and by mileage, whichever lands first.
- Specification. The right oil grade, the right fluids, parts that meet the maker's spec.
- Proof. Itemised invoices naming what went in, plus a stamp or a digital record.
The parts question, which genuinely isn't settled
Read the parts wording carefully, because there are two different tests hiding in it. Kia's basic warranty excludes damage from "the use of inferior quality parts", which is a test of quality. Its anti-perforation warranty goes further and excludes perforation resulting from "the use of new parts not sold or approved by Kia", which is a test of brand.
The CMA's guidance has something to say about the second kind. Paragraph 5.37 says warranty conditions requiring the maker's own branded parts, for replacements not covered by the warranty, "may similarly be caught by the Chapter I prohibition".
So a term demanding the maker's own badge on a part sits in contested ground. I'm not going to pretend the guidance cancels the term, or the term the guidance. While the car's in warranty, parts matching the maker's specification are the low-risk choice. A good garage will tell you what they fitted without being asked.
When it does still have to be the dealer
Four situations where the general answer won't help.
Repairs the warranty is paying for. Paragraph 5.36 only reaches work "not covered by warranty". Nothing in it stops a manufacturer directing you to its own network for a job it's footing the bill for. In practice, that's how warranty repairs get handled.
Service-activated and extended cover. Some makers hand out extra warranty on top of the standard one, earned by servicing with them. Toyota's service-activated warranty is the plainest example: its own site says "yes, you have to have your vehicle serviced at any Authorised Toyota dealer". That's a separate product with its own rules, so read yours rather than assuming.
The CMA also treats an extended warranty sold years after the car was bought differently. That's at paragraph 5.39. By then the dealer no longer has the same hold over the customer.
Finance agreements. A PCP or a lease is a separate contract from the warranty. Some carry their own servicing conditions, including servicing at a franchised dealer, to protect what the car is worth at the end of the term. Check the agreement, not the warranty.
Motorbikes. The Order defines a motor vehicle as one "having three or more road wheels". A two-wheeled bike sits outside it entirely.
That doesn't make a restrictive term in a bike warranty lawful or unlawful. It just means this Order has nothing to say about it.
When a manufacturer can still refuse a claim
There's a real limit on all this. It's a fair one.
Paragraph 5.37 keeps one right for the manufacturer. Competition law doesn't stop a maker, "or any other warranty provider", from "legitimately refusing to honour a warranty claim". That applies where the situation leading to the claim is "causally linked":
- "i) to a failure on the part of a repairer to carry out a particular repair or maintenance operation in the correct manner", or
- "ii) to the failure of a spare part supplied by a third party".
So a bad service can cost you a claim. Those are two separate limbs.
What the manufacturer can't do is stop at "an independent serviced it". The link has to be causal, and it has to run to the specific failure you're claiming for. Paragraph 5.40 puts a fence round the rest of it. Any other warranty restriction that indirectly limits your right to use an independent repairer is "likely to be within scope of the Chapter I prohibition".
And if the garage's work did cause the failure, you aren't stuck. Your claim moves to the garage instead. Section 49 of the Consumer Rights Act 2015 requires the work to be done with reasonable care and skill. Section 55 lets you require repeat performance at their cost.
Our guide to what to do when a mechanic didn't fix your car walks through that route.
Your warranty isn't your Consumer Rights Act protection
These get blurred constantly, and they're different things.
The manufacturer's warranty is a promise from the manufacturer. Your Consumer Rights Act 2015 rights run against the trader who sold you the car. Different party, different remedies, different time limits.
That matters here for one practical reason. Losing an argument with a manufacturer doesn't touch what you can ask of the dealer, and vice versa. Section 30 also requires a guarantee to say plainly that your statutory rights aren't affected by it.
Buy privately and the satisfactory-quality rights largely fall away, so a transferred manufacturer warranty may be all the cover there is. Our guide to used car warranty options covers what you already have and what's worth paying for on top.
What to keep, so a claim can't be argued with
Nobody wins a warranty argument with a memory. They win it with paperwork.
Keep the itemised invoice from every service, not just the stamp. It should name the oil grade, the filters and any parts fitted, along with the date and the mileage. That's the document that answers a "was it serviced to our schedule" question in one go.
The stamped service book still helps, and so does the manufacturer's digital service record where your garage can write to it. Not every maker lets an independent update that record, so ask before you book rather than after. A full service history is worth real money at resale too, whoever did the work.
If I'm honest, the invoices are the ones I'd guard. A stamp proves somebody had a rubber stamp. An invoice proves what actually went into the car, and it's the thing a warranty administrator can't wave away.
If the manufacturer refuses anyway
Ask for the refusal in writing, and ask which term of the warranty it relies on. That one question settles most of it, because a refusal that can't name a term usually isn't one.
If it names a servicing-location term, quote the guidance back. Paragraph 5.41 is the useful one. Terms that "clearly state the consumer's right to use the services of an independent repairer without losing the benefit of the warranty are unlikely to give rise to competition concerns". That's the CMA telling manufacturers what good terms look like.
Next stop is The Motor Ombudsman. Its New Car Code covers the terms of manufacturers' warranties, and it's free to use. Check your maker is on the accredited list first, because a manufacturer that hasn't signed up can't be taken there.
There's one route to skip. The CMA says plainly that it "cannot step in or advise on individual complaints", so reporting your refusal there won't get your gearbox fixed. It's worth doing anyway if you think the term is a general one, since that's how systemic problems get spotted. Just don't wait on it.
This is one corner of running a used car. Our ownership guide covers the rest.
FAQs
Will using an independent garage void my new car warranty?
No, not on its own. The CMA's guidance covers this. A servicing restriction is likely to be caught by the Competition Act 1998's Chapter I prohibition where a warranty is made conditional on one thing. That thing is non-warranty work being done only inside the maker's own network. The service still has to follow the manufacturer's schedule. It has to use the right parts and fluids. And you still need to keep the paperwork.
Does the service book have to be stamped by a main dealer?
No. Any competent garage can stamp it. What backs the stamp up matters more. Keep the itemised invoice showing the date, the mileage, the oil grade and the parts fitted. Some manufacturers also hold a digital service record. Not all of them let an independent garage write to it, so ask before you book.
Can a manufacturer refuse a warranty claim because an independent serviced my car?
Only if it can link the two. The CMA's guidance says competition law doesn't stand in the way of a refusal in two cases. One is where the failure was caused by a repairer doing a job badly. The other is where a third-party part failed. "An independent touched it" isn't enough on its own. Ask them to put the reason in writing. And if the garage's work did cause the fault, your claim moves to the garage under the Consumer Rights Act 2015.
Do I have to use the manufacturer's own branded parts?
Some warranty terms do say so. Kia's anti-perforation warranty, for one, excludes perforation caused by "the use of new parts not sold or approved by Kia". The CMA's guidance says a condition of that kind may itself be caught by competition law. Those two positions sit in genuine tension, and this article can't settle it for you. While the car's in warranty, parts matching the maker's specification are the safer bet. Your garage should tell you exactly what they fitted.
Does any of this apply if my car is on PCP or a lease?
Your warranty rights are the same. Your finance agreement is a separate contract. Some PCP and lease deals do require servicing at a franchised dealer, to protect what the car is worth at the end of the term. Read the agreement itself, because that's the document with the condition in it.