Inconsistency in the TFL ULEZ API and the Pay ULEZ TFL page

I am trying to get my vehicle ULEZ state from the API and am finding that my car is returning null from their API, my friends car works fine. The Pay ULEZ page on the TFL website however functions perfectly for both and I am wondering if there is some limitation for the vehicles you can check or the database for the publicly available API is somehow different.

For reference the two plates are KC16FHB and LC16FEM and this is consistent with the results from their swagger API page.

If you need any more information please let me know.


Interesting. I can confirm that the two attempts and do indeed return null and good results in turn.

Is there another public database of UK registration numbers that could be use as a comparison?


I do not know about public free APIs but the one I provided below works for both vehicles. It doesn’t contain ULEZ compliance directly but it definitely has both vehicles.

Any ideas would be greatly appreciated!

EDIT: The website only allows you to use their “search” function for the car info but clearly they also have a purchasable API, my bad for not being clear.

Hi, the ULEZ Compliance endpoint I believe was only in place for queries prior to the ULEZ go-live last year and that it would be decommissioned shortly after.

I don’t believe the dataset is maintained and have asked the Product Owner to look into removing the endpoint.