An OEM cross-reference is a mapping table that links a part's original manufacturer (OEM) code to its equivalent, aftermarket and other-brand alternatives. With it, a dealer or customer can find every alternative for that part from a single code or vehicle. So how does it work, and how are equivalent (aftermarket) parts identified correctly? Let's break it down.
What is an OEM cross-reference?
OEM (Original Equipment Manufacturer) is the maker of the original part a vehicle leaves the factory with. A cross-reference links that original part's code to equivalent (aftermarket) parts made by other brands. For example, enter a brake pad's OEM code and you'll see products from brands like Bosch, TRW or Ferodo that do the same job.
OEM vs OES vs aftermarket parts
- OEM: The vehicle's original part, sold under the car brand's logo.
- OES: The same part, sold by the supplier that makes the OEM part under its own brand.
- Aftermarket (equivalent): An alternative part made by independent brands that performs the same function — usually more affordable.
A cross-reference ties these three worlds together, so the customer can see which option fits and at what price.
How do you find equivalent parts / cross-references?
- From the OEM code: Enter the original code and list all equivalents.
- From the vehicle (VIN / plate): Select the vehicle and see the fitting parts and their alternatives.
- With TecDoc data: Standard databases like TecDoc provide millions of cross-references and vehicle-part links out of the box.
Why does an accurate cross-reference matter so much?
In spare parts, the most expensive mistake is the wrong part: returns, shipping cost, lost time and lost trust. A solid cross-reference layer lets the dealer find the right part the first time — sales speed up and returns drop. Offering aftermarket alternatives also increases basket size and conversion.
Cross-reference at Vilyonix
Vilyonix cleans your spare-part data and manages it in one hub; it builds OEM / competitor codes, aftermarket matches and vehicle fitment in a TecDoc-compliant way. On your B4B platform, this data lets dealers find the right part — and all its alternatives — from a vehicle, plate or OEM code in seconds. See how we build the data layer on our TecDoc & Data Services page.