US microchip registration in the UK

Hello

It's been three years since I moved with my cats.  Just recently I was prompted to remember that I've never updated my contact information in regards to their microchips.

That got me to thinking about the common types of microchip readers at Vet offices and whether databases are internationally accessible.

If I pay the money to my chip providers (HomeAgain and Avid) and my cats were lost, would the average UK vet/shelter be able to connect to their/my information?

Any one with experience/knowledge in this area?

Cheers
Holly

My cat has a HomeAgain chip ("installed" in the US) and both vets I've used in the UK have been familiar with them, so I assume it would be OK if he got lost.

thanks Chary