From 6th April 2016 all dogs in England and Wales must be microchipped, they still have to wear a tag with your name and address too

And we’d highly recommend a phone number (and a clip on tag with the walker’s number if they’re out with a dog walker) so they can be returned to you even more quickly without necessarily having to visit a vet or dog warden to check the microchip data.
Sources for more information: