OE vs OEM vs aftermarket, how to make sure a part actually fits your registration, which parts are safe to buy cheap and which never are, plus warranties, returns, click and collect and whether a garage will fit parts you supply. Last checked: 18 August 2026.
Quick answer: buying car parts online in the UK
Affiliate disclosure: this guide contains affiliate links to GSF Car Parts and we may earn a commission at no extra cost to you. Last checked 18 August 2026.
Search by registration first and price second, buy OEM rather than OE where you can, and never buy budget brakes, steering, suspension, timing belts or catalytic converters. Filters, bulbs, wipers, screenwash and oil are safe to buy on price. Use click and collect if the car is off the road, because a branch beats a courier.
OE vs OEM vs aftermarket
Car manufacturers do not make filters, brake pads, clutches or alternators. They buy them from Bosch, Valeo, LuK, TRW, Mahle and Denso and put their own box around them. OE is the part in the manufacturer box. OEM is the identical part in the supplier's own box, usually 30 to 60 per cent cheaper. Quality aftermarket is an independent brand built to the same specification, and budget unbranded should be limited to consumables.
Using OEM parts does not void a manufacturer warranty in the UK under block exemption rules, provided the work is done properly and recorded. What causes warranty disputes is poor workmanship and no evidence, not the brand on the box.
Making sure the part fits
Registration lookup reads the DVLA record, which knows the model and engine size but not always the exact variant. Where two options appear for one registration the difference is normally engine code, brake disc diameter, build date, a VIN split or the drivetrain and trim. Photograph the old part's markings and the VIN plate before ordering, and keep the VIN handy for imports and personalised plates.
Parts never to buy on price alone
Brake pads, discs, hoses and calipers; timing belt kits and water pumps; suspension arms and ball joints; catalytic converters, which must be type-approved to pass emissions; sensors and coil packs; and clutches, where the gearbox coming out twice costs far more than the part. Cabin filters, wiper blades, bulbs, screenwash and brake cleaner can be bought on price with no downside.
Warranty, returns and customer-supplied parts
Most factors offer 12 to 24 months on parts, but a warranty replaces the component and not the labour to fit it again. Unfitted parts in original packaging are generally returnable under UK distance selling rules, while opened electrical parts often are not. Many garages will not fit customer-supplied parts because they cannot warranty the repair, so ring ahead and ask about the labour rate before ordering.
Cheap car parts without buying rubbish
Cheap and bad are not the same thing. Buy OEM rather than the manufacturer-branded box and you get the identical component from the same factory without the badge tax. Buy a service kit rather than four separate filters. Buy pads and discs together rather than pads now and discs in three months, because otherwise you pay the labour twice.
The other half is timing. Emergency buying is where money disappears. If you know the brakes are down to 4mm or the cambelt is due, order in advance and you get the choice of brand and the online price. Cheap is genuinely fine on cabin and air filters, wipers, bulbs, screenwash, brake cleaner, copper grease and sump washers. It never is on anything that stops, steers or holds the car up.
Car spares, motor factors and main dealers compared
An online motor factor is normally cheapest for branded parts, with next-day delivery or same-day click and collect. The local factor counter costs more at retail but hands you the part today when the car is already stripped. A main dealer is dearest and often order-in, but is the right call for model-specific trim, ECUs, keys and recall items.
Marketplace sellers look cheapest and carry the most risk on brand and returns, so keep them for consumables. Breakers and salvage yards are excellent value on panels, mirrors, lights, alloys, trim and switchgear. The pattern is simple: the cheap options are cheap on things that do not wear.
Used, refurbished and reconditioned car parts
A good used part is a respectable repair on the right component — wing mirrors, door handles, light units, tailgates, alloys, seats and interior trim are often the only economic way to fix an older car. Ask for the donor vehicle's mileage, and for electrical items ask whether the part was tested off the car.
Reconditioned is different again: an alternator, starter, turbo, steering rack, DPF or gearbox stripped, re-shelled with new wear items and warranted. On expensive assemblies a recon unit with a proper warranty beats both a used one and a cheap new copy. Watch the surcharge — you pay a deposit on the old unit and get it back on return. Do not buy used brakes, clutches, timing belts, bushes, wheel bearings, catalytic converters, airbags or seatbelt pretensioners.
Work out what you need before you buy it
Half the wasted money in home repairs is the right part fitted for the wrong reason. Confirm the fault first with the free OBD2 fault code lookup, the MOT failure decoder, the car symptom checker or a free MOT history check, then order once. If you are still not sure which part it is, ask a mechanic for £14.99 before you spend anything on parts.
Frequently asked questions
Where is the best place to buy car parts online in the UK?
Buy from a factor that lets you search by registration and shows the brand it supplies. Registration lookup matters more than headline price, because the wrong part at the right price is still money wasted.
Are cheap online car parts any good?
Filters, bulbs, wipers and cabin filters from a quality aftermarket brand are fine. Brakes, steering, suspension and airbag-related parts should be OE or a recognised OEM brand such as Bosch, TRW, Brembo, LuK or Valeo.
How do I know a part will fit my car?
Search by registration, then cross-check the part number against the one you are removing. Where two options appear the difference is usually engine code, brake disc diameter or build date.
Is it cheaper to buy my own parts and get a garage to fit them?
Sometimes, but many garages will not fit customer-supplied parts because they cannot warranty the work, and those that do often charge a higher labour rate.
What is the difference between OE, OEM and aftermarket parts?
OE is the manufacturer-branded box, OEM is the identical part from the company that made it in their own box, and aftermarket is an independent brand built to the same specification. OEM is usually the best value.
Do online car parts come with a warranty?
Reputable factors offer 12 to 24 months on most parts. Keep the invoice, and remember the warranty covers the part and not the labour to fit it a second time.
Can I return a car part I ordered by mistake?
Usually yes if it is unfitted and in original packaging, under UK distance selling rules. Electrical parts and anything fitted or marked are often non-returnable.
What car parts should I never buy cheap?
Brakes, steering and suspension parts, timing belt kits and water pumps, airbag and seatbelt components, sensors and coil packs, and catalytic converters, which must be type-approved.
Where can I buy cheap car parts in the UK without buying rubbish?
Buy OEM instead of OE and you take 30 to 60 per cent off the identical component. Buy a service kit instead of separate filters, and order before the car is off the road, because emergency buying is where people overpay.
How do I find car parts by registration number?
Type the registration into the parts site's lookup and it filters the catalogue to parts listed as fitting. It reads the DVLA record, so where it offers two choices the split is nearly always engine code, brake disc diameter, build date or drivetrain.
Are car parts cheaper online than at a motor factor counter?
Usually yes, because online lists run closer to trade pricing, and most big factors let you reserve online and collect at the counter. A trade account normally beats both if you run a garage.
Is it worth buying used or breaker's yard car parts?
For panels, mirrors, trim, light units, alloys and switchgear, yes. For anything that wears or is safety-critical — brakes, clutches, belts, suspension, sensors — buy new, because you cannot see the remaining life in a second-hand wear item.
What are pattern parts and are they safe?
Pattern is trade slang for a non-manufacturer copy. Quality pattern parts from established brands are what most independent garages fit daily. The risk is unbranded pattern parts with no testing data, no warranty and no comeback.
Does fitting non-genuine parts void my car's warranty?
Not in the UK. Block exemption rules let you use matching-quality parts and an independent garage without losing a manufacturer warranty, provided servicing is done to schedule and recorded.
How quickly do online car parts get delivered in the UK?
Next working day is normal for stocked lines, with same-day click and collect if the local branch has it. Special-order items such as ECUs or colour-matched panels can take several days, so check availability before stripping the car down.