Microchipping Number: What It Is and Where to Find It
Where your pet's microchip number is recorded, what the prefix does and doesn't tell you, and how to use the number to check which database holds the record.
Your pet's microchip number is usually written on the paperwork from the vet, rescue or breeder. If you can't find it, a vet, dog warden or rescue centre can scan the pet and read it off. The number is 15 digits long: a three-digit prefix plus a 12-digit code that's unique to your pet.
That 15-digit format is the standard for compliant chips. Where the prefix is a manufacturer code it always starts with a 9, and a country code never does. Some older chips work differently, with 10-character numbers that can include letters, so don't worry if what you're looking at is shorter or has letters in it.
There's no name, address or phone number stored on the chip; it only holds a number. Your contact details sit on a database that's linked to that number, and that record is the part you keep right. The number is what you need to check the registration, update the record, or move it into your name.
Where to find your pet's microchip number
Start with the paperwork from when your pet was chipped or rehomed. The number is usually on the microchip certificate from the vet, breeder, rescue or implanter, and it may also be on adoption papers or vaccine records. If your pet was registered online, searching your inbox for "microchip" or the chip company's name should turn up the original registration confirmation email. If you recently adopted or bought your pet, the person or organisation you got them from will have it too.
Your vet may have the number on file, so it's worth a quick call before you book anything. Not every practice keeps chip numbers on their records, so if yours doesn't, a scan appointment is the fallback.
If your pet has travelled abroad, the number will also be on their travel documents. It has to be recorded on an animal health certificate, so any certificate issued for a trip will carry it. On an old pet passport your vet should have written the number in, and a GB passport issued before 1 January 2021 is still accepted when you're bringing your pet back to Great Britain from an EU country.
If you've found a pet and want to know whose it is, you won't have any of this. A phone can't scan a chip, though you can buy a scanner that links to a phone; otherwise the pet needs scanning by someone with a reader, such as a vet or rescue centre. Pet Database's guide to which database your pet might be on and how to check explains what happens with the number after that.
If it isn't on any of your paperwork
Ask a vet or rescue centre to scan your pet. Write the number down as soon as you have it, and keep it somewhere you'll find again, such as a photo or note on your phone.
Chips can move from the spot between the shoulder blades where they're implanted, so whoever scans should start there and sweep slowly in an S shape down towards the tail. A chip only counts as failed when a full body scan with a working scanner has found nothing.
A few older chips can't be picked up by any UK-approved scanner. These aren't true failures, but a dog with one has to be rechipped with a compliant device. If a chip has failed or migrated out and been replaced, the databases aren't told automatically. It's down to you to put the new number on the record.
If you're the registered owner, you can also ask the database directly. In England, you have the legal right to be given the record held on your cat or dog, and the microchip number is one of the details that record has to contain.
What the first three digits tell you
The first three digits are a prefix. It's either a country code, used where a country runs an official identification scheme, or a manufacturer code, which points to the company that supplied the chip.
You can look a manufacturer code up on the register of chip devices run by ICAR (the International Committee for Animal Recording) to see who made it. Code 900 is shared across several makers, so for a 900 chip you'd need the number range as well as the prefix to pin it down.
What to do with the number once you have it
Run it through Pet Database's chip checker. You type in the number and it searches several UK databases in one go. It shows whether the chip is registered and which database holds the record, but not the owner's contact details. It's free to use and needs no account.
What you do next depends on what it shows. If the record is there and the details are right, you're done. If your address or phone number has changed, contact that database and put it right. If the chip comes back unregistered, the number leads nowhere yet, and the record needs setting up before it can help get your pet home. Pet Database's page on checking whether your pet's chip is registered walks through that, and what to do after your pet is chipped covers the registration itself.
The number only works if the record behind it does. Check a chip with Pet Database to find out where that record lives.
