How to Find Any Car Part by Number (UK Part-Finder Guide)

Finding the right part is half the battle in any repair or restoration. Get the number right and you avoid returns, wasted postage and the dreaded "close enough" fit. This guide explains how to read original-equipment (OE) and aftermarket part numbers, where they are physically stamped, how to cross-reference between brands, how to decode a UK VIN, and how to use our request-a-part service when a component is discontinued.

OE numbers vs manufacturer (aftermarket) numbers

Every replaceable component carries at least one identifier. There are two families you will meet:

• OE / OEM numbers are issued by the vehicle maker (e.g. a Ford, BMW or Vauxhall part number). They are the most reliable way to guarantee fitment because they are tied to a specific vehicle application.
• Manufacturer / supplier numbers are issued by the company that actually produces the component (e.g. Bosch, Valeo, NGK, TRW, Febi). One physical part often carries BOTH an OE number and the supplier's own catalogue number.

Because a single component can have several valid numbers, the trick is to capture every number printed on the old part, then cross-reference them. A genuine OE number narrows the search fastest; a supplier number lets you buy a quality equivalent for less.

Where common part numbers are stamped

Numbers are usually moulded, etched, printed on a label or laser-marked. Clean the part first — grime hides characters, and a 0 can look like an O or a D. The table below shows where to look for the most frequently replaced components.

Component	Where the number is found	What to capture
Alternator	Stamped tag riveted to the body, or printed on the case near the pulley	Bosch/Valeo/Denso number + amp rating
Starter motor	Foil label or cast number on the housing	Supplier number + kW rating
Brake pads	Printed on the friction backing plate and on the box (WVA number)	WVA number + FMSI where present
Spark plugs	Etched on the ceramic insulator	Full plug code (e.g. NGK BKR6E)
Headlight / fog light	Moulded into the lens or rear housing, plus an E-mark approval code	OE number + E-mark (e.g. E11)
Battery	Top label	Type code (e.g. 096), Ah, CCA, terminal layout
Filters	Printed on the body or end cap	Supplier number (Mann, Bosch, etc.)
Wheel bearing / hub	Etched on the outer race or hub flange	SKF/FAG number + ABS ring note
Sensors (ABS, lambda, MAF)	Moulded on the connector body or printed sleeve	OE number + connector pin count
Window regulator / motor	Sticker on the motor or stamped on the plate	OE number + side (NSF/OSF)

Step-by-step: identify and cross-reference a part

1. Remove and clean the old part. Wipe off oil and dirt so every character is legible.
2. Photograph every marking. Capture both faces, the connector, and any tags. Numbers can wrap around edges.
3. Write down all numbers and codes. Separate OE numbers (vehicle-maker format) from supplier numbers (Bosch, Valeo, etc.) and approval marks (E-marks, WVA).
4. Cross-reference. Enter the supplier number into a catalogue to find equivalents, then confirm against the OE number. If two sources agree, you have a match.
5. Verify against your vehicle. Check the part is listed for your make, model, engine and build date — not just a similar trim.
6. Confirm physical details. Count electrical pins, measure mounting centres, and note left/right (NSF/OSF) before ordering.

Decoding a UK VIN

The Vehicle Identification Number is a 17-character code that uniquely identifies your car and unlocks exact fitment data. Find it on the windscreen base (driver's side), on a plate in the engine bay or door pillar, and on your V5C logbook. The structure is standardised:

• Characters 1-3 (WMI): World Manufacturer Identifier — who built the car and where.
• Characters 4-9 (VDS): Vehicle Descriptor Section — model, body style, engine and restraint system.
• Characters 10-17 (VIS): Vehicle Identifier Section — model year, assembly plant and the unique serial number.

The letters I, O and Q are never used in a VIN, so if you read one of those it is actually a 1 or a 0. Quoting the full VIN when you contact us removes almost all fitment guesswork, especially on facelifted models where the part changed mid-year.

Sourcing discontinued and hard-to-find parts

When a part is no longer listed by the maker, all is not lost. Many superseded numbers were replaced by an updated OE number that still fits — a process called supersession. Others are covered by quality aftermarket equivalents, or can be found through specialist and breaker networks. For older vehicles, our classic and vintage car parts range is the first place to look.

If you cannot find it on the shelf, send us the numbers. Our request-a-part service tracks down discontinued, NLA (no longer available) and obscure components across our supplier and specialist network. Tell us the full VIN, every number on the old part, and a photo, and we will identify a genuine OE, superseded or equivalent part. Browse by manufacturer on our shop by make hub, or by component brand on shop by brand to start the search yourself.

Common pitfalls to avoid

• Trusting a year alone. A model can use several part variants in one year depending on build date and engine — always confirm against the VIN.
• Mixing up similar codes. A trailing suffix (e.g. -A vs -B) often signals a meaningful revision; don't drop it.
• Ignoring left/right. Many parts are handed. NSF means nearside front (UK kerb side), OSF means offside front (driver's side).
• Overlooking the E-mark. Lighting must carry a valid European approval mark to be road-legal in the UK.

Get the numbers right and the part fits first time. When the trail goes cold, our request-a-part team and make-by-make catalogue are here to finish the hunt. Use code SAVE10 for 10% off your order, with tracked UK delivery on every parcel.

Frequently asked questions

Where do I find my car's VIN in the UK?

Look at the base of the windscreen on the driver's side, on a metal plate in the engine bay or door pillar, and on your V5C logbook. It is a 17-character code that never uses the letters I, O or Q.

What is the difference between an OE number and a supplier number?

An OE number is issued by the vehicle maker and guarantees fitment for a specific application. A supplier number is issued by the company that builds the part, such as Bosch or Valeo. Many parts carry both, so capturing every number helps you cross-reference.

Can you find a discontinued or no-longer-available part?

Yes. Send us the full VIN, every number stamped on the old part and a clear photo. Our request-a-part service checks superseded OE numbers, quality equivalents and specialist networks to track down hard-to-find and discontinued components.