If the vehicle is tested within the calendar month prior to when the MOT is due, the test certificate will run from the date of the test to one year after the expiry date of the current certificate. For example, if the current certificate was due to expire on 1 April 2011, and the vehicle was presented on or after 2 March 2011, the certificate would run from the test date until 1 April 2012.
The same rule would also apply when the vehicle is taken in within a calendar month of its first MOT. In this case, the vehicle owner would need to present their registration document before the test is started.
If the vehicle is tested earlier than one month before its due date, the MOT will only run for twelve months.