An ISO-compliant microchip is one that meets ISO 11784 and 11785: it operates at 134.2 kHz and carries a 15-digit number. If your pet’s number has 15 digits, it is ISO. Nine or ten digits means it is not.
That is the entire test, and you can apply it to your own paperwork right now.
Why it matters
134.2 kHz is the international standard. Canada, Europe, Asia and Australia run on it. The United States never fully moved, so 125 kHz and 128 kHz chips remain in wide circulation here alongside ISO ones.
Two consequences follow:
- Travel. Most countries require an ISO chip for import. A non-ISO chip generally means either implanting a second ISO chip before travel, or carrying a scanner that reads yours — which some authorities will not accept.
- Being read at home. A US scanner that reads only 125 kHz will not read an ISO chip, and will report the animal as unchipped. This is why universal scanners exist.
Is my brand ISO?
Do not go by brand — several manufacturers sell both ISO and non-ISO product lines, so the name on the certificate does not settle it.
Count the digits on your actual number. 15 digits is ISO. Anything shorter is not. If you are unsure which chip your pet has, have it scanned and read the number off the scanner rather than trusting old paperwork.
The prefix guide identifies the manufacturer from the leading digits.
ISO is not the same as registered
An ISO chip is readable by any compliant scanner anywhere in the world. That is a genuine advantage and it is also where the advantage stops.
Once the number is read, it still has to resolve to a current registry record with a working phone number. A perfectly compliant ISO chip on the correct frequency returns nothing useful if the registration was never completed or never updated. Standards get the number read. Registration gets the pet home.
Look your number up and see what it returns today.
Common questions
Are all 15-digit microchips ISO compliant?
A 15-digit number is the ISO format, and in practice it is the reliable indicator for a pet owner. If you need certainty for international travel, ask the implanting vet to confirm the chip meets ISO 11784/11785 and put it on the certificate.
What if my pet has a non-ISO chip and we are moving abroad?
Talk to your vet well in advance. The usual route is implanting an additional ISO chip. Record both numbers and register both, so a scan of either resolves to you.
Can a scanner read both ISO and non-ISO?
A universal scanner reads 125, 128 and 134.2 kHz. A single-frequency scanner reads one, and silently misses the rest.
