Under the Control of Dogs Order 1992, all dogs, whilst in a public place, must wear an ID tag, with the following information:
Address and Postcode (or house number and postcode as a minimum)
A contact telephone number is also recommended
We recommend dogs wear a quality, fitting harness, so it's a good idea to have an ID tag on both the collar, and harness as backup.
Since April 2016, it is compulsory for all dogs to also be microchipped.