How to Add Number Plate Lookup to a Shopify, WooCommerce or Magento Car Parts Store

To add number plate lookup to a car parts store you need three things: a licensed vehicle data provider that returns a TecDoc K-Type for a UK registration, a small server-side service that holds the API key and caches results, and fitment data on your products so the lookup has something to filter. The front-end box is the easy part; the platform (Shopify, WooCommerce or Magento) mostly decides where the last two live.

This guide walks through the whole thing. It is written for store owners and the developers they brief, and it reflects how we build reg lookup integration for parts retailers.

What a reg lookup actually does

The customer types a VRM. Your site sends it to a data provider, gets back the vehicle (make, model, derivative, engine, fuel, build dates, often a partial or full VIN) and, critically, a TecDoc K-Type: the ID that part catalogues use to say “this article fits this vehicle type”. Your store then filters categories, search and product pages to articles linked to that K-Type, and remembers the vehicle for the rest of the session.

If you skip the K-Type, all you can do is show the customer their car’s name. That is not a parts finder.

Why DVLA VES is not enough on its own

The DVLA Vehicle Enquiry Service is free and official, and it is the first thing every developer finds. It returns registration number, make, colour, fuel type, engine capacity, CO2, year of manufacture, month of first registration, tax and MOT status and dates, type approval, wheelplan, revenue weight and Euro status. It does not return model, VIN, mileage or keeper details, and it has no concept of a K-Type. “FORD, 1596cc, DIESEL, 2014” does not tell you which Focus, let alone which brake disc.

Two more practical points from the DVLA developer portal: access is one API key per company with a per-client usage plan and system-wide throttling (HTTP 429 when you exceed it), and, as of September 2026, DVLA is not accepting new VES registrations while it upgrades the system. New projects should plan on a commercial provider from the start. Use VES, when you can get it, for tax and MOT status only.

Choosing a data provider

For a parts store the provider must return a K-Type (or a list of candidate K-Types) alongside the DVLA fields. The main UK options are Vehicle Data Global (the provider UK Vehicle Data now redirects to), cap hpi, and aggregators such as One Auto API that front several sources behind one key. The DVSA MOT History API is free and worth adding for mileage and MOT expiry, but it does not return fitment data either.

Pricing is per lookup. VDG publishes tier-one prices: Vehicle Data (UK) at £0.153 pay-as-you-go or £0.081 on subscription, ex VAT, with credits valid for twelve months and no setup fee (check current pricing before you budget). cap hpi and One Auto API price on quotation. Whichever you choose, read the licence: results cannot be bulk-scraped or resold as a database, and a VRM tied to an enquiry is personal data under UK GDPR, so record your lawful basis and retention period.

Our vehicle data API page compares the providers in more detail.

The flow, end to end

1. Capture and normalise the VRM. Uppercase, strip spaces, validate against UK formats (current, prefix, suffix, dateless, Northern Ireland). Reject obvious junk before it costs a lookup.
2. Check the cache. Key on VRM plus date. A vehicle does not change engine overnight; cache hits for 30 to 90 days cut the bill dramatically.
3. Call the provider from your server. Never from the browser. The API key stays on your side, and you control rate limits and error handling.
4. Resolve ambiguity. Providers often return several K-Types for one VRM where engine variants share a description. Disambiguate by engine code, kW or VIN prefix; if you still cannot, ask the customer: “Is yours the 1.6 TDI 105 or 110?”
5. Filter the catalogue. Query products linked to the K-Type, respecting linkage criteria (from chassis number, fitting position, PR codes).
6. Persist the vehicle. Store it in the session or customer account as “My Garage” and expose it to search, category and product pages, and to your eBay and Amazon listing tools so fitment stays consistent across channels.

Step 5 assumes your products already carry K-Types. If they do not, that is a part fitment mapping project and it comes first.

Platform by platform

Shopify

Shopify does not let you run server code inside the store, so the lookup lives in a small app or proxy you host (or a third-party fitment app). The registration box goes in as a theme app extension. The K-Types are stored on each product as a list metafield, and the filtering is done either through Search & Discovery filters on a derived tag, or by your app querying the Storefront API. Keep the range in mind: tens of thousands of SKUs with hundreds of K-Types each stretches metafields, and a fitment table in your app’s own database is cleaner.

WooCommerce

WooCommerce gives you full server access, so the lookup is a plugin: a REST endpoint that validates the VRM, checks a transient cache, calls the provider and returns the vehicle. Store K-Types as a custom taxonomy (one term per K-Type) so WordPress indexes them and category filtering is a taxonomy query, not a meta query. Keep the plugin lean and test on staging with every WordPress and WooCommerce release.

Magento / Adobe Commerce

Magento is the natural home for large fitment catalogues. Build a module with a service class for the provider, a controller for the AJAX lookup, and a dedicated fitment table (product ID, K-Type, criteria) rather than a product attribute, so 200,000 linkages do not bloat the EAV tables. Index into OpenSearch for fast “fits your car” filtering across layered navigation. The vehicle sits on the customer session and quote so it is visible at checkout.

Common mistakes

Exposing the API key in front-end JavaScript. Not caching, so every page refresh costs a lookup. Assuming the DVLA “model” field is reliable (it is free text from the V55 and reads “GOLF GT TDI 140” one day and “GOLF” the next). Treating first-registration date as build date; parts changed mid-year get mis-assigned. Ignoring imports and Northern Ireland plates, which often return no K-Type at all. Every one of these has cost a client sales before they came to us.

FAQ

Is the DVLA API free to use on my website?

VES is free, subject to DVLA’s terms, but registrations are paused as of September 2026 and it returns no model or K-Type. For a parts finder you need a commercial provider regardless.

How much does a reg lookup cost per search?

It depends on provider and volume. Vehicle Data Global publishes a Vehicle Data (UK) price of £0.153 pay-as-you-go or £0.081 on subscription, ex VAT; others quote. Check current pricing, and cache results so repeat searches are free.

Can I do this on Shopify without an app?

Not properly. Shopify themes cannot hold a secret key or call a provider securely, so you need a hosted proxy or an app. The box itself can live in the theme.

Do I need TecDoc data as well?

You need K-Types on your products, which usually come from TecDoc data or a supplier that publishes TecDoc linkages. The lookup returns the vehicle’s K-Type; your catalogue has to know which parts match it.

Ready to build it? Our reg lookup integration service covers provider selection, the proxy, caching and the fitment mapping, on Shopify, WooCommerce or Magento.