Pet Microchip Lookup: Every Registry Explained (US, UK, Australia, Canada)

A microchip is not a tracker. It's a passive glass capsule the size of a grain of rice that stores one thing: a number — usually 9, 10 or 15 digits. The number means nothing until a registry maps it to your contact details. That's the whole system, and it's also the whole problem: there are dozens of registries, and in most countries no single national database. Here's how to navigate them, whether you found a chipped pet or need to check your own pet's registration.

United States: start with the AAHA lookup

The US has no national pet registry — chips are registered with whichever company the implanter or owner chose. The definitive starting point is the free AAHA Universal Pet Microchip Lookup (aaha.org): enter the chip number and it tells you which participating registries hold or sold that chip — most major ones participate (24PetWatch, AKC Reunite, HomeAgain, AVID, PetLink, Michelson Found Animals, BuddyID, Fi Nano, and others). Then you contact that registry directly — the lookup identifies the registry, it doesn't hand out owner details.

The main US registries:

• HomeAgain (Merck) — one of the largest; registration typically bundled at implant, with optional paid recovery services. Reporting a pet "lost" broadcasts to their network.
• AKC Reunite — the AKC's recovery service; accepts any brand of chip, one-time enrollment, 24/7 recovery line.
• 24PetWatch / Pethealth — common in shelter-implanted chips; free basic registration with paid add-ons.
• PetLink (Datamars) — free lifetime registration, popular for cats.
• Michelson Found Animals — nonprofit, accepts any chip free of charge.
• AVID — manufacturer plus registry; common in older chips and breeders.

Two edge cases worth knowing:

• Chips starting with "900" are shared manufacturer codes — the lookup may return several possible registries. Start with the first listed and work down.
• Registries die. In early 2025, US company Save This Life ceased operations, orphaning its chips — their numbers no longer resolve to owners. If your pet's chip was ever registered with a service that shut down, re-register the same number with any surviving registry (Found Animals and others accept any brand, often free). A chip tied to a dead database is effectively no chip.

United Kingdom: Defra-approved databases

Microchipping is mandatory for dogs (England, Wales and Scotland since 2016; Northern Ireland since 2012) and for cats in England since June 2024 — and the law requires your details to be current on a compliant database. There is no single national registry either: the UK has around fifteen Defra-compliant databases. The largest is Petlog (run by the Kennel Club); others include Animal Tracker, Identibase, SmartTrace, PetScanner and Chipworks. Not sure which database holds a chip? Petlog operates a Check-a-chip tool (petlog.org.uk) that identifies the database from the chip number — the UK equivalent of the AAHA lookup.

Australia: state registers plus national databases

Microchipping is compulsory for cats and dogs in most states, but registration is handled per state (e.g., the NSW Pet Registry) alongside national commercial databases — Central Animal Records and Australasian Animal Registry are the two big ones. There is no single national lookup: a finder should scan the chip, then try the state register where the animal was found plus the national databases. Council pounds and vets know which databases their state cross-checks.

Canada: manufacturer registries and one province

No national registry. Most Canadian chips sit in manufacturer/commercial registries — EIDAP, 24PetWatch, PetLink — or in the BC Pet Registry (run by the BC SPCA), which participates in the AAHA lookup. If a chip number doesn't resolve in the AAHA tool, Canadian vets commonly check EIDAP and the provincial options manually.

Found a pet with a chip: the 5-minute protocol

1. Get it scanned — any vet clinic, shelter or animal control office scans free, in seconds.
2. Note the number exactly (9, 10 or 15 digits; no spaces).
3. Run it through the lookup — AAHA for US/Canada, Check-a-chip for UK, state register + national databases for Australia, petmaxx.eu for European and international chips.
4. Contact the registry the lookup names — they'll contact the owner. Registries don't hand you the owner's details; privacy works that way by design.
5. If the chip is unregistered, ask the registry for "trackback" information — the implanter (a shelter, breeder or vet clinic) who bought the chip can often identify the animal.

Own a chipped pet: three things to do today

• Verify the registration resolves. Run your pet's number through the lookup for your country — the number is on the implant paperwork or obtainable from a free scan.
• Update your details after every move or number change. An out-of-date phone number is the single most common reason a found pet can't be returned — the chip works, the human data doesn't.
• Flag the pet lost the moment it goes missing. Most registries have a lost-pet report that marks the record and, in some cases, notifies nearby vets and shelters. Pair it with a neighborhood alert — the chip reaches the professional channel, the alert reaches the neighbors who will actually spot the animal.

And a belt-and-suspenders tip: chips fail silently (migration, unreadable, dead registry). A visible ID — collar tag or QR tag — gives a finder an instant contact channel that needs no scanner.

FAQ

Can I track my pet's location with the microchip? No — a microchip has no battery, no GPS, no signal. It's readable only at contact range with a scanner. Location tracking is what GPS collars are for; the chip is permanent backup ID.

Does scanning or registering cost money? Scanning is essentially always free (vet, shelter, animal control). Registration cost depends on the registry — from free (Found Animals, PetLink, BC Pet Registry) to one-time or annual fees. Re-registering an existing chip number to keep it traceable is usually cheap or free.

My pet is chipped but I never registered it — is it too late? No. Get the number from any free scan, then register it with the registry the chip belongs to (AAHA lookup will name candidates) or any free registry that accepts all brands. An unregistered chip can still sometimes be traced via the implanter's trackback record — which is exactly why you should register it now.

Do international (ISO) chips work in the US? Yes — ISO 15-digit chips (11784/11785 standard) read on universal scanners used by US vets and shelters. Non-ISO 9/10-digit chips read on most universal scanners too, but older shelter scanners occasionally miss them — worth knowing if you imported a pet.

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Chipped or not, identification only works if someone can reach you. Post a lost-pet alert the moment your pet goes missing — and if you've found a chipped animal, the registry route above plus a found report covers both channels.