Microchip
I was talking to a vet and he said many people forget to change the microchip details. Some are still in the breeders details and many forget to change the info when they move or change their phone number.
Unless you have your pet's microchip number on file, it can only be obtained by having your pet scanned at a veterinary clinic with a microchip scanner.
There are a number of web sites to check the the details are correct.
https://www.petlog.org.uk/look-up-a-microchip/search/