Microchipping and ID: Getting Lost Pets Home

A microchip is a tiny implant with a number that links to your contact details on a database, so a vet or shelter can reunite you with a lost pet. It only works if your details are current. Many places require chips for dogs, and some for cats, while a collar tag gives anyone who finds your pet an instant way to call you.

How a Microchip Works

A microchip is about the size of a grain of rice and is implanted under the skin, usually between the shoulder blades, by a vet or trained implanter. It has no battery and doesn't track location. When a scanner passes over it, it shows a unique number. A vet, shelter or warden looks that number up on the database to find the registered keeper.

Chips are used in dogs, cats, rabbits, ferrets, horses and some birds and reptiles. Ask your vet to scan the chip at check-ups to make sure it can still be read.

Keep Your Details Up to Date

A chip is only as good as the details behind it. When you adopt or buy a pet, make sure the chip is transferred into your name. Update the database whenever you move house or change phone number. In the UK, gov.uk notes that keeping the record up to date is the owner's job and the database may charge a fee for changes.

If you don't know which database your pet's chip is on, a vet can scan it, and many countries have a lookup service that tells you which database holds a number.

Collar Tags and Licenses

A tag lets anyone who finds your pet contact you straight away, without a scanner. In the UK, a dog in a public place must still wear a collar and tag with the owner's name and address, even when chipped. Many US cities and counties require a dog license, often with proof of current rabies protection, and some issue a license tag to wear.

For cats, use a quick-release (breakaway) collar if your cat wears one at all, so it can't get caught. Many cat owners rely on the chip alone.

ID Gear

Each button opens a search in your own country's Amazon store. As an Amazon Associate we earn from qualifying purchases.

An engraved tag with your phone number is the quickest way home. Cats need quick-release collars. A microchip scanner isn't needed at home, but a microchip-reading pet door or feeder uses the chip for everyday convenience.

The Law: Rules Differ by Country

Whether chipping is required depends on where you live and the species.

United Kingdom: all dogs must be microchipped and registered by 8 weeks old. In England, cats must be microchipped and registered by 20 weeks old (since 10 June 2024); free-living farm, feral and community cats are exempt. Check gov.scot, gov.wales and nidirect for the other nations.
Ireland: dogs must be microchipped and registered on an approved database, and owners also need a dog license (gov.ie).
United States: there is no national microchip law; licensing and any chip rules are set by states, cities and counties.
Elsewhere: Canada (provinces and municipalities), Australia (your state or territory) and New Zealand (your district or city council) all have their own registration and chip rules.

Pets traveling between countries usually need a chip as part of the health paperwork; see traveling abroad with pets.

If Your Pet Goes Missing

Search nearby first, calling calmly; cats often hide close to home.
Report the loss to the microchip database so the record is flagged.
Call local vets, shelters and the dog warden or animal control.
Post on local lost-pet groups with a clear, recent photo.

Frequently Asked Questions

What owners ask about chips and tags.

Does a microchip track my pet's location?

No. It has no battery or GPS; it only gives a number when scanned. For live location, you need a separate GPS tracker.

Does microchipping hurt?

It's a quick injection under the skin, much like a routine jab. Many owners have it done during another vet visit or when a pet is neutered.

My pet is chipped. Does it still need a tag?

A tag lets anyone call you at once, and in the UK dogs must wear one in public by law. Cats can wear one on a quick-release collar or rely on the chip.

How do I update my details?

Contact the database your pet's chip is registered with. Your vet can scan the chip if you don't know the number.

Do cats have to be microchipped?

In England, yes, by 20 weeks old. Elsewhere, check your national and local rules; it is recommended almost everywhere even when not required.