The short answer
Most cats in the US have 15-digit ISO (FDX-B) chips, but older or imported cats may have 9-digit AVID or 10-digit FDX-A chips. SureFlap states it reads all three; PetSafe's microchip door states 15-digit chips. If your cat's chip won't read, collar ID discs (Cat Mate) or RFID tags are alternatives.
What makers state
| Device | Reads |
|---|---|
| SureFlap Microchip Cat Flap / Pet Door | 9 (AVID Secure), 10 (FDX-A), 15 (FDX-B) |
| SureFeed Microchip Pet Feeder | 9, 10 and 15-digit |
| PetSafe Microchip Cat Door | 15-digit |
| Cat Mate 360 | 15-digit ISO or Cat Mate ID discs |
| Closer Pets MiBowl | ISO and AVID 15-digit or ID tags |
Check your cat's chip
- Your vet's records list the chip number and its length.
- A handheld reader such as ISENVO reads 15-digit FDX-B chips at home.
- Count the digits: 9, 10 or 15.
If the chip won't read
- Cat Mate Elite I.D. disc flap: collar discs for up to 9 cats.
- Cat Mate electromagnetic flap: collar magnets.
Products mentioned
Questions readers ask
Will a microchip flap read my cat's chip?
Check its length: SureFlap states 9, 10 and 15-digit support.
What if my cat isn't chipped?
Use a flap that reads collar ID discs or tags.


