how long is a mot certificate valid for

An MOT certificate is generally valid for 12 months from the date of the last MOT test or the expiry date of the previous certificate. This means that if the MOT test is done before the current certificate expires (up to 28 days in advance), the new MOT will still expire 12 months from the previous expiry date, essentially extending the validity without losing any days. You cannot drive a vehicle with an expired MOT certificate unless driving to a pre-booked MOT or repair appointment. The new MOT certificate expiry date is clearly printed on the certificate itself, and you can renew the MOT up to one month before the current certificate expires without affecting the renewal date for the following year.