i don't think they are country code's because jazz's starts 985 as well and she was born and bred in this country, microchipped at birth, and as far as i know she hasn't actually left the country
Pet ID, the distributor of the '999' microchips, has now agreed to address this issue by ensuring that all microchips supplied after the beginning of October, 1999 carry a proper manufacturer code of '967' and by exchanging any of the '999' coded microchips still unused after October 4.