The shell is the tortoise's fingerprint
Before any paperwork, take the photographs, because a tortoise carries its best identifier on its own body. The arrangement of scutes, the plates that make up the shell, differs between individuals, and the underside, the plastron, is the most reliable surface of all because it is sheltered from wear and sun-bleaching. Photograph the tortoise from directly above, from each side, and of the plastron with the tortoise held securely and briefly by someone experienced, in plain daylight with no shadows across the shell. Add a close shot of any distinguishing feature: an old scar, an unusually shaped scute, a notch in the shell rim. A rescue comparing a found tortoise against a set of photographs like these can make an identification that no verbal description could match.
Microchipping: the record that travels with the animal
Photographs prove identity to someone who has them; a microchip proves it to anyone with a scanner. A vet can implant a chip in a tortoise, usually in a hind leg, and the chip number is then registered on a database against your name, address and phone number. Two habits make the chip worth having. First, keep the chip number written down with your other records, because you will be asked for it the moment the tortoise is lost. Second, ask the vet to scan for the chip at routine visits, because chips can occasionally shift position, and a chip that cannot be found cannot reunite anybody. If you move house or change your number, updating the chip registration is as important as having the chip at all.
The written record worth keeping
Alongside chip and photographs, keep a short written profile: species, sex if known, straight carapace length measured in a straight line rather than over the curve, weight, and where and from whom the tortoise came to you. Paperwork that arrived with the tortoise, such as a breeder's record or paperwork for a protected species, belongs in the same folder. This record is what lets a vet confirm that the tortoise in front of them, whose shell has grown and changed a little with age, is the same animal described years earlier, because size, sex and species stay constant even as markings soften at the edges.
Keeping the trail warm, not just made
Identity records only work if they stay findable and current. Tell your vet the chip number so it sits on the tortoise's clinical record as well as the chip database. Make sure a family member knows where the folder and photographs live, because the person who finds the tortoise missing may not be you. Refresh the shell photographs as the tortoise grows, since a juvenile's pattern stretches and darkens.
All of it, chip number, shell photographs, measurements and your contact details, is exactly what KinsLe's Pet Pass gathers into one verified ID card for the tortoise, ready to show any vet or rescue that ever needs to trace the animal home.