This involves inserting a small device, slightly larger than a piece of long grain rice, under the patients skin. The device returns a unique number when it is scanned by a special scanner. The number is registered to the owner and means that if the pet is lost the owner can be traced. Inserting the chip is easily accomplished in most pets and is a relatively cheap way of providing identification that is not easily lost.
For the 'Pet Passport' scheme and certain breed health schemes microchipping is a requirement.