To verify a cat microchipping claim, treat the chip number as a starting point, not an answer: have a vet or shelter scan the cat with a universal scanner, run the number through the AAHA Universal Pet Microchip Lookup Tool to find which registry holds it, then contact that registry to confirm the record matches the person making the claim. A microchip is a passive RFID transponder — a grain-of-rice-sized capsule carrying one unique 9-, 10-, or 15-digit ID number and nothing else. That limitation shapes everything else. Because the chip stores only a number, every claim built on it — "she's chipped to me," "the chip proves ownership," "pay to renew your registration" — depends on records and paperwork held elsewhere, and each of those can be checked.
Table of Contents
- What a microchip actually stores, and what it cannot do
- Verifying a chip number: what the lookup tool tells you
- Why "the vet said no chip" is weak evidence
- A microchip claim in a sale or dispute
- The renewal scam and other red flags
- Keeping your own record verifiable
- Frequently Asked Questions
What a microchip actually stores, and what it cannot do
The American Veterinary Medical Association's microchipping FAQ is blunt on the central point: a pet microchip is a passive RFID transponder carrying only an identification number. It has no battery and no satellite link. It does nothing at all until a scanner passes within a few inches and powers it. So any advertisement, listing, or app claiming a microchip will "locate" or "track" a missing cat is describing a product the chip is not.
GPS collar trackers exist and work, but they are separate devices with batteries that need charging. Conflating the two is the single most common red flag in this space. What the chip does well is survive. It does not fall off, fade, or get removed by a new owner the way a collar tag does, which is why it remains the backbone of shelter reunification.
Verifying a chip number: what the lookup tool tells you
The AAHA Universal Pet Microchip Lookup Tool queries participating registries and returns which registry or manufacturer holds a record for that number. It does not return a name, address, phone number, or email.
Privacy rules make that the correct design, but it means the tool answers a narrower question than most people expect. In practice a lookup gives you one of three results, and each leads somewhere different: None of these outcomes verifies that a chip belongs to a named person. That step always requires the registry or the implanting clinic.
- **A registry is named.** The number is real and registered somewhere. Contact that registry directly; they will usually confirm or deny whether a specific person's details match, or contact the registered owner on your behalf.
- **A manufacturer is named but no registry.** The chip was distributed but never registered, or was registered with a non-participating service. The implanting clinic's records are the next stop.
- **Nothing is found.** Either the number was transcribed wrong, or the record sits outside the participating registries.
Why "the vet said no chip" is weak evidence
Two scanning problems mean a negative result deserves a second look. The first is frequency. The AVMA's page on microchipping of animals explains that ISO 11784/11785 defines the 134.2 kHz, 15-digit standard endorsed by the AVMA, AAHA, WSAVA and the ASPCA — but 125 kHz non-ISO chips remain widespread in the United States. A scanner that reads only one family will silently miss the other. Ask whether the clinic used a universal, forward- and backward-reading scanner. The second problem is technique and migration.
Chips can drift from the implant site between the shoulder blades toward the elbow, shoulder or sternum. Maddie's Fund's guidance on how to do a good job scanning for a microchip describes a slow full-body sweep — roughly half a foot per second, scanner held close to the coat, a snake pattern down the back and both sides — and repeated, not once. The shelter data backs this up. In the study of 7,704 microchipped animals entering 53 US shelters, 971 animals — 12.6% of those scanned more than once — had a chip that an earlier scan had missed, and 97.9% of chips detected later in a stay had gone undetected earlier. One negative scan is a weak result. Two careful scans, days apart, with a universal scanner, is a real one.
A microchip claim in a sale or dispute
A chip record is supporting evidence, not proof of legal ownership. As Veterinary Practice News reports, US law treats pets as property and courts weigh possession alongside documentary "indicia of ownership" — adoption or purchase receipts, veterinary records naming the owner, licensing.
A chip number in a listing proves nothing on its own. If a breeder, rescue, or private seller tells you a kitten is chipped and registered, ask for these before money changes hands: A seller who supplies a number but resists every one of those checks is the pattern to walk away from. So is a chip whose registered owner turns out to be a third party the seller cannot explain.
- The full chip number in writing, and the implanting clinic's name.
- A veterinary record or implant certificate that names the current registered owner.
- Confirmation of who will file the transfer of registration, and when.
- Agreement that you may scan the cat yourself at your own vet before completing the sale.
The renewal scam and other red flags
Microchip registrations do not expire. That single fact defeats the most common current scam: emails, letters or calls demanding a fee to "renew" or "re-register" a chip before it lapses. KSN's report on the scheme notes the Better Business Bureau carries complaints against operators of this type.
Some registries do sell genuine optional paid tiers — lost-pet alerts, extra contact slots — and those are legitimate products. The distinguishing feature of the scam is urgency plus a threat: your chip is about to become invalid, your pet will be unprotected, pay now. Legitimate registries do not deactivate a chip record for non-payment of a renewal you never agreed to. Other signals worth treating as warnings: a "chip" sold as a tracker, a number that returns nothing on the AAHA lookup while the seller insists it is registered, pressure to skip your own vet's scan, and any request to send payment through a channel the registry itself does not list on its official site.
Keeping your own record verifiable
The reunification numbers explain why this matters. In the 53-shelter study published in JAVMA, microchipped cats were returned to their owners 38.5% of the time against 1.8% for unchipped cats — and the leading reason chipped animals were *not* returned was incorrect or missing owner information in the registry. The chip worked; the record had gone stale. So the practical task is annual, not one-time: look up your own cat's number, confirm which registry holds it, log in, and check the phone number and email are ones you still use.
Add a second contact who is not at the same address. If you moved, changed carriers, or adopted from someone who never completed a transfer, that is the gap to close. Owners in England have a legal deadline on top of this. Per the RSPCA's guidance on the Defra rules, microchipping cats has been compulsory since 10 June 2024: cats must be chipped before 20 weeks old with details kept current on a Defra-compliant database. A non-compliant owner has 21 days to comply or faces a fine of up to £500 — a rule aimed at the 2.8 million UK cats Defra estimated were unchipped.
Frequently Asked Questions
Can I look up who owns a cat from its microchip number myself?
No. The AAHA tool tells you which registry holds the record, and the registry itself controls whether owner details are released or the owner is contacted on your behalf. Expect to make a phone call.
My cat's chip was implanted abroad. Will a US vet be able to read it?
Probably, if the clinic uses a universal scanner. Chips implanted under the ISO 11784/11785 standard are 15 digits at 134.2 kHz; a scanner that reads both ISO and older 125 kHz chips handles either.
A found cat scanned negative at one clinic. Is it worth trying again?
Yes. In the shelter study, 97.9% of chips found later in an animal's stay had been missed on an earlier scan. Ask for a slow full-body scan with a universal scanner, and repeat it a few days later.