Ran this check on my own car as a potential buyer used HPI (who also own the National Mileage Register) and both HPI and NMR had incorrect mileage showing, different to the service history and the MOT history records. When I queried it, they said they would need details of the service history and MOT history to be supplied. When I told them they could check the MOT history themselves, they said it wasn't their responsibility to check it !!! So buyer didn't buy, HPI / NMR don't care their info is wrong, but mycarcheck was right. Which is good but didn't really help.