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eBay · Fitment data · 7 min read

K-Type to ePID: why your website and eBay disagree.

Your website says the part fits a 2015 Fiesta ST. Your eBay listing says it doesn't — or says it fits a diesel it shouldn't. Same part, same business, two answers. The cause is nearly always the gap between two vehicle catalogues that were never designed to talk to each other.

By Maxxd · Published 21 September 2026

Two catalogues, two sets of IDs

Your website's fitment (if it's built properly) is keyed to K-Types — TecDoc's vehicle variant IDs, which is also what your reg-lookup provider returns when a customer types in a plate.

eBay Motors doesn't use K-Types. It has its own vehicle catalogue, and every vehicle in it has an ePID (eBay Product ID). When you add "parts compatibility" to a listing, you're attaching ePIDs. When a buyer sets their car in My Garage and filters results, eBay is matching ePIDs.

Both catalogues describe the same cars. They were built by different organisations, at different times, with different ideas about what counts as a distinct variant. That's the whole problem.

Where the two disagree

  • Granularity. TecDoc will split a model by engine code and power output; eBay's UK catalogue often splits by engine size and trim name. One ePID can cover three K-Types. One K-Type can straddle two ePIDs.
  • Naming. "Fiesta Mk7", "Fiesta VI", "Fiesta (CB1)" and "Fiesta 2008–2017" are the same car described four ways. Text matching between catalogues fails constantly.
  • Date ranges. Facelift boundaries and model-year changes rarely land on the same dates in both catalogues.
  • Coverage. eBay's catalogue is thinner on imports, low-volume variants and older cars. TecDoc is thinner on some grey imports and JDM models. Either way, some vehicles simply don't exist on one side.
  • Change. Both catalogues are updated continuously. eBay merges, retires and corrects ePIDs. A mapping that was right last year has drifted.
The trapMost sellers built their eBay compatibility by hand years ago, from model names, and their website fitment separately, from supplier data. Nobody ever reconciled the two. So they disagree — and every "doesn't fit" return is a coin-toss as to which channel was wrong.

The wrong fix: copying one channel into the other

The tempting shortcut is to export your eBay compatibility lists and import them to the website (or vice versa). It's quick and it's wrong. You import eBay's naming and granularity into a system that needs K-Types for reg lookup, so the website filter gets fuzzy. Or you push K-Type-derived model names to eBay, where they don't resolve to ePIDs and get silently dropped.

One channel's data structure can't be the master for the other. You need a translation layer.

The right fix: a maintained K-Type → ePID map

Keep one master fitment dataset keyed to K-Type. Build a separate mapping table — K-Type on one side, ePID(s) on the other — for every vehicle in your range. When you push compatibility to eBay, translate through the map. When eBay changes, update the map, not thousands of listings.

Building it

  1. List your vehicles. Every distinct K-Type in your master fitment. For a specialist seller that might be 300; for a general factor, tens of thousands.
  2. Pull eBay's catalogue for those makes and models. Via the eBay API (the Taxonomy and Catalog APIs expose compatibility properties and vehicle lists) or your listing tool's vehicle lookup.
  3. Match automatically where you safely can. Make, model, year range, engine size and fuel type give a confident match for most mainstream variants. Score each candidate; accept only high-confidence matches.
  4. Resolve the rest by hand. The awkward 10–20%: facelift boundaries, power variants, imports. This is skilled work and it's where most of the value is.
  5. Record one-to-many honestly. If one K-Type maps to two ePIDs, store both. If an ePID covers three K-Types, all three rows point to it. Don't flatten.
  6. Flag the unmappable. Vehicles that exist in one catalogue and not the other. You'll need to decide, per part, whether to list without compatibility or use eBay's nearest variant with a fitment note.

Maintaining it

  • Re-validate the map on a schedule — quarterly for most sellers, monthly for large catalogues.
  • Watch bulk-upload error reports. A sudden spike in "invalid compatibility" errors usually means eBay changed something.
  • When you add a vehicle to the master, add its ePID mapping at the same time. Make it part of the process, not a clean-up job.
  • Version the map. When a return comes in, you want to know what the mapping said at the time of listing.

What it fixes

With the map in place, a fitment edit happens once, in the master, and flows to the website, eBay and (via the same principle) Amazon and Google Shopping. Compatibility on eBay becomes complete rather than partial, so your listings appear for buyers filtering by vehicle. The website and eBay stop contradicting each other. And when something does come back as "doesn't fit", you can trace exactly which row was wrong — and fix it everywhere in one edit.

This is the core of our eBay compatibility service and it starts with the fitment data work. If you'd like to know how far apart your two channels currently are, the free fitment audit checks exactly that.

Questions

K-Type / ePID FAQ

Is there an official K-Type to ePID conversion table?
No. TecDoc and eBay maintain their vehicle catalogues independently and neither publishes a mapping to the other. Some listing tools and data vendors sell partial mappings; in practice most sellers need to build and maintain their own for the vehicles they actually sell for.
Can I just paste my eBay compatibility list into my website?
You can, but you'll import eBay's vehicle naming and granularity, which won't match your reg-lookup provider's K-Types, so the website's fitment filter won't work reliably. Keep the master keyed to K-Type and translate outwards to ePID, not the other way round.
How often does eBay change its vehicle catalogue?
Continuously, in small ways: new model years, corrected variants, merged or retired ePIDs. A mapping that was right last year will have drifted. Re-validate it on a schedule and whenever you see unexpected compatibility errors in bulk uploads.

Free, no strings

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