What is an OE part number, and why it matters when buying used

An OE part number is the original equipment manufacturer's own code for a specific part, and matching it is the single most reliable way to buy the exact right part for your car. Sometimes called an OEM number, it is stamped or printed on the component itself. Match the number and you remove almost all the risk of buying the wrong thing, which is why it is the most powerful tool you have when buying used parts.

Why is the part number better than the part name?

Because one car can have several versions of the same part. Across a single model's production run, the manufacturer often changes a component for facelifts, different trims, different engines, or left and right hand drive. The name, say "front bumper" or "alternator", covers all of them. The part number identifies the one that fits your exact car. That is the difference between a part that bolts straight on and one that almost fits.

Where do I find my OE part number?

The most reliable source is the old part itself. Manufacturers mould, stamp or print the number onto the component: on the inside face of a bumper, the back of a mirror, the body of a headlight, the casing of an alternator or gearbox. Clean the area and look for a long alphanumeric code in the maker's format. If you no longer have the old part, your registration lets a breaker look up the correct number for your car.

Will a part with a different number ever fit?

Sometimes, yes. Manufacturers supersede part numbers, so a newer number can replace an older one and still fit. Parts are also shared across models and even across badges within the same group, so a part from a different car can be exactly right if its number matches or supersedes yours. This is where a knowledgeable seller helps, because they know which numbers cross over. When in doubt, ask before you buy.

How do I use the number to buy a used part?

Find the number on your old part, then match it to the number in the listing. If a listing does not show a part number, ask for it. At Partsworth we surface the manufacturer part number on our listings precisely because it is the buyer's best guarantee of a correct fit. Send us your number or your registration and we will confirm the match before you buy.

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Browse by make to find your car's parts, including BMW, Ford and Mercedes, and have your old part number ready. Every part is inspected and tested, ships with free tracked UK delivery, and is covered by our 30 day returns policy. Parts worth your trust.