Micro chipping is a common practice where a tiny chip (the size of a grain of rice) is inserted under the skin between the shoulder blades of your pet.
If your pet is found after straying or becoming lost, any vet or rescue company should scan your pet for a microchip. If a micro-chip is found the individual number will correlate to your contact details enabling them to contact you.
It is vital you keep your contact details up to date with the microchip company. If these are not changed when you move or change telephone numbers it could result in your pet never being returned home to you. The micro-chip company may charge a small fee for the changing the details.
If you have taken on a rescue animal it is wise to check if it has been micro-chipped. If this is so you will need the details of the chip so you are able to change the details. If the previous owners are unsure then get your new pet checked as it could be some ones long lost pet or even a pet that has been stolen.
Before a micro-chip is inserted it common practice to scan the animal before insertion to check to see if they are not already chipped.