Typing a number plate into a tyre search is the fastest way to find the right tyres, and it spares the job of decoding a sidewall. It is genuinely handy, with one situation where it pays to double-check.
How it works
Behind the scenes, a registration search matches the plate to vehicle records and returns the factory tyre size for that car, then lists tyres that fit. So instead of reading 205/55 R16 91V off the rubber and typing it in, the plate does it automatically. On an online tyre site like Tyres.co.uk, typing in a number plate does the same thing automatically: it pulls the factory size straight from the car's record and brings up the tyres that fit, which is why it is a quick place to start.
Why it's useful
The appeal is speed and accuracy:
- No sidewall reading in a dark, dirty wheel arch
- No typos in a string of numbers and letters
- Instant matching tyres in the right size
- A simple starting point for anyone unsure where the size even lives
For the large majority of cars running their original wheels, the plate lookup is spot on.
The one catch
There is a single situation to watch. A registration search returns the factory size, what the car wore when it left the production line. It does not know if the wheels have been changed since. So if a car is on:
- Aftermarket or plus-sized alloys, or
- Staggered fitment (different sizes front and rear)
then the size actually fitted may differ from the factory one the plate returns. In those cases the sidewall is the truth, and the new tyre has to match what is physically on the car, not what the lookup suggests.
The safe routine
The reliable approach is to use both:
- Start with the plate to pull the likely size fast
- Confirm against the sidewall before ordering
For a standard car the two agree and it takes seconds; on a modified car the sidewall settles it. Either way, it is one of the checks worth doing before buying online.
From the workshop: reg search is brilliant ninety-five times in a hundred. The five that catch people are cars on big aftermarket alloys, the plate says one size, the wheels say another. Quick glance at the sidewall and you know for sure. Start with the plate, finish with the sidewall.
Sources and accuracy. This reflects how registration tyre search commonly works at the time of writing. The sidewall of the fitted tyre is always the definitive size for a given car. If anything here looks wrong, get in touch and we will check it and put it right.
Common questions
How does finding tyres by registration work?+
You enter the number plate, and the system looks up the car's factory tyre size from vehicle records, then shows tyres that fit. It saves reading the sidewall and avoids size typos, which is why most tyre websites offer it as the quickest way to start.
Is searching by registration accurate?+
For a standard car, yes, it returns the size the car left the factory with. The exception is a car on aftermarket or plus-sized wheels, or with different front and rear sizes, where the fitted size may differ. In those cases the sidewall is the truth, so cross-check it.
Why does registration search show the wrong size sometimes?+
Because it returns the original factory size, not what is physically on the car. If someone has fitted larger alloys or non-standard wheels, the actual tyre size will differ from the factory one the plate lookup gives. Always confirm against the sidewall before buying.
Should I trust registration search or the sidewall?+
Use registration search to start quickly, then confirm against the sidewall before ordering. The plate gives the factory size, which is right for most cars, but the sidewall shows what is actually fitted, and that is what a new tyre has to match.