Microchip number not 15 digits? What it means and what to check
Older and foreign chips use shorter codes or letters, so an unusual number is often fine once you know why. Work out which situation you're in and how to confirm your pet's registration is sound.
You go to register your pet and the number on the paperwork from the chipping appointment doesn't look like the 15-digit figure you were expecting. Maybe it's shorter, or there's a letter in it. In the UK, that number should be 15 digits long and all numeric. If yours is different, there are two usual reasons. Either the chip is older or foreign and uses another format, or the number has been miscopied somewhere. The chip itself stores only that number; your name, phone and address are kept on a database record that the number points to.
What a standard microchip number looks like
A standard chip holds 15 digits with no letters, made up of a three-digit prefix and a twelve-digit identifier. The prefix is either a manufacturer code, which starts with 9, or a country code, which never starts with 9. The prefix identifies who made the chip. It doesn't point to any particular database.
Why some chip numbers are shorter or include letters
Before the 15-digit format became standard in the UK, chips were made to different specifications. One older type carries a 10-digit number, built into non-standard chips that run at 125 kHz. Other older formats include a 10-character number mixing digits and a letter, such as 111111112A, and formats with digit groups separated by asterisks. A chip fitted abroad may use another format. A pet living in the UK still needs a UK registration, even if there's an overseas record.
In England, Wales and Scotland, every dog older than 8 weeks must be microchipped, and the chip has to meet the modern standard. A dog with a non-conforming chip needs a compliant one implanted in its place.
Check it isn't a copying slip
Fifteen digits is a lot to transcribe, and slips happen. The number is written on the implanter's certificate, the registration email, your vet's records and any pet passport. Comparing all four is the quickest way to spot a wrong pet microchip number. Look for digits run together with no spaces, a missing digit in the middle, or a letter O read as a zero. If a database search comes back blank, the first thing to do is double-check what you typed in. A single wrong digit points to a different pet, or to no pet at all.
Can every scanner read an older chip?
Standard vet and warden scanners are built for modern chips. Some older types, including the 125 kHz chips above, can need a different reader. In practice, an older pet with a non-standard chip can be harder to identify if they go missing and the finder's scanner only picks up the modern format. If you're not sure what format your pet has, ask the vet to scan them at the next appointment and read out what comes up.
Checking where the chip is registered
Even with the right 15-digit number, the number alone doesn't tell you where your pet's record sits. The prefix only identifies the chip's maker; the record can sit on any UK microchip database that meets government standards. The free Pet Database chip checker searches the main UK databases for a 15-digit code in one go [pd:C1, pd:A3]. It tells you whether the number is on record and which database has it, without releasing the owner's contact details.
If your number has fewer than 15 digits, or any letters, the checker won't match it. Contact the vet, rescue or database you think has the record. Confirm the correct number and format with them, and ask them where your pet's registration sits.
With the right number in hand, check the chip across the UK databases and make sure your contact details on the record are current.
