I have always estimated my millage for carbon calculators as I am not very good at keeping track of the millage. When I took the family car for its MOT today they took me through the documents and happened to point out the millage and emissions readings. I had never really looked at the MOT certificate in detail before but mine has odometer readings back to 2010.
So if you are looking for information on your historic millage just check out your MOT certificate.
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