This has probably been covered before, but I was wondering if I could get a Heritage certificate for my 1990 Cooper and there appeared to be gaps in the availability years on the BMIHT website, so I emailed them to confirm and they replied:
Unfortunately the later 'Rover Group' Mini factory records we not passed onto the BMIHT by either Rover Group or MG Rover. As a result, they did not survive the collapse of MG Rover in 2005, making us unable to produce Heritage Certificates for these cars.