Each chip carries a unique number which, when scanned, identifies your pet on the National Chipworks database. This information is stored securely alongside your name and contact details, so that you can be informed if your pet is found wandering on their own.
At the time your pet is chipped, you will be required to pay a small one-off fee. After that all you have to do is remember to update your contact details if they ever change (e.g. if you move house or change you telephone number or email address), to make sure your furry friend is easily identifiable if they are ever separated from you.