Microchip ID Systems manufactures only Certified ISO microchips.  ISO refers to the ‘International Standards Organization’.
To be Certified as ISO, the chip must be manufactured as follows:
1)  Operate at a radio frequency of 134.2 kHz.
2)  Contain 15 digits, the first three of which are the unique assigned manufacturer ‘code’ . See note.
3)  Examples of our code: 965000000123456, 933000123456789

We also make a special ISO chip that has been approved by the USDA and the FDA for compliance within certain livestock industries. See the 840-ID Official Microchip.

* BEWARE:   Do not use microchips that begin with the NON unique ISO code of 900 (nine-zero-zero).  Hundreds of companies (outside of the USA) have been issued these temporary ISO manufacturer codes.  It is nearly impossible to track an unregistered ‘900’ chip back to a manufacturer.