If you own a dog it must be microchipped. If not you will be committing an offence. It is also illegal to transfer a dog to a new owner if the dog has not been microchipped.
If you buy a puppy it must be microchipped before you take it home with you as the new owner.
An authorised officer from Havering Council can serve notice on a dog owner requiring them to microchip their dog. If they fail to do so they are committing an offence and Havering Council can seize the dog, microchip it and recoup the costs from the owner.
For more information visit the Dogs Trust website: www.dogstrust.org.uk