Taken from :http://www.bobmckay.co.uk/Frame2.html

There are two important things to understand about the statutory test process. The vehicle must have a full examination on its return if it leaves the test station. The maximum fee is set by regulations but the amount charged is up to the garage, they may choose not to charge at all. Nevertheless a full examination must still be carried out in those circumstances requiring it.

If the vehicle stays at the testing station for repair and retest then no fee can be charged for the retest.

If the vehicle is brought back to the same test station and re-tested before the end of the next working day (the next day the test station is open for testing. Note that this differs from the "next working day" definition given for other situations in "abbreviations and definitions" of the 5th edition of the Testing Guide) for one or more of the following items only:


ABS warning Bootlid Brake pedal antislip Emissions Direction indicators
Hazard warning Doors Dropsides Lamps Fuel filler cap
Headlamp aim Horn Tailgate Loading door Mirrors
Rear reflectors Tailboard Registration plates Seat belts (not anchorages)
Seats VIN Steering wheel Sharp edges/projections
Windscreen Wipers Washers Wheels and tyres