A microchip is a small radio-frequency identification device about the size of a grain of rice that is implanted under the skin between the shoulder blades. It provides a permanent form of identification that cannot be lost, removed, or altered — unlike a collar with tags, which can fall off or be removed.
How Microchips Work
The microchip contains a unique identification number. When a scanner passes over the chip, it powers up and transmits that number. Shelters, veterinary clinics, and animal control facilities have universal scanners that can read chips from all major manufacturers. The ID number is registered in a database with the owner's contact information. The chip itself has no battery and requires no power source — it is completely passive and will last the cat's entire lifetime.
The Registration Step
A common misconception is that a microchipped cat is automatically identifiable. In reality, the chip is useless without current registration in a database. When a chipped cat is found and scanned, the shelter or vet contacts the chip manufacturer or registry to look up the owner's contact information. If the registration is out of date, or if the chip was never registered, the trail goes cold. Update your contact information whenever you move or change phone numbers.
Universal Scanner Compatibility
Modern chips are required to be readable by universal scanners that detect all frequencies used worldwide. If you adopted your cat internationally or travel internationally, confirm that the chip meets ISO standard 11784 or 11785 — the international standards for microchip identification in companion animals.