Microchipping Pets Explained: How It Works and Why It Matters

Vet-reviewed via PetHealth+ · Last reviewed June 2026

A microchip is a **permanent ID chip** the size of a grain of rice, injected under the skin. It is **not a GPS tracker** — when a scanner reads the chip, the database returns **your contact details**. Registration and **keeping details updated** are essential; an unregistered chip cannot bring your pet home.

How microchipping works

The chip contains a unique number, not your personal data directly. Implantation takes seconds with a sterile needle between the shoulder blades. The chip remains passive until a scanner activates it. Shelters and vets scan every stray animal; matching numbers link to owner records on commercial or government databases.

Who can implant a chip?

Veterinary professionals and trained implanters perform the procedure. Puppies and kittens are often chipped at first vaccination or before sale. Adult pets can be chipped at any age. Sedation is rarely needed.

Registration — the critical step

Implantation alone is useless without database registration. Some breeders register initially — new owners must transfer ownership. Keep registration certificates accessible. Multiple databases exist; know which one holds your pet’s record.

Migration and failures

Chips occasionally migrate down the leg or shoulder — scanning the whole body locates them. Rarely, chips fail to read; annual vet scans confirm function. Collar tags remain valuable for immediate contact without a scanner.

Legal context

In England, Scotland, and Wales, dogs must be microchipped by eight weeks and registered to the keeper. Similar rules apply across much of Europe. Cats are increasingly covered by local mandates. Travelling abroad often requires a microchip for pet passport schemes.

If your pet goes missing

Report the chip as lost to the database — some offer alert services. Contact local vets, shelters, and social media lost-pet groups. Never rely on chip alone; active searching reunites more pets than waiting for a scan.

Frequently asked questions

Does a microchip track my pet's location?

No — microchips are not GPS devices. They store an ID number read by a scanner when a found pet is taken to a vet or shelter.

Does microchipping hurt?

Insertion is a quick injection between the shoulder blades — similar to a vaccination, with minimal discomfort.

Is microchipping legally required?

Requirements vary by country and region — dogs are legally microchipped in much of the UK and EU; check local laws.

What if I move house or change phone number?

Update your contact details on the microchip database immediately — an unregistered or outdated chip cannot reunite you with your pet.