The minimum checks you need before moving off is the main mirror, right mirror and the right side blind spot.The main mirror gives an exact life size image of what's behind. This needs to be checked first.The last check before moving away should be your right blind spot (left if you're pulled up on the right hand side of the road). It's important you check here last because if you have vehicle directly next to you, you must know before pulling away. This is your most vulnerable spot.
After you have completed your observations, ensure there is
no delay between this and moving off. If there is a delay for what ever reason,
then complete your observations again before moving off. It only takes a few
seconds for circumstances to change.
Warning - Failure to see a vehicle in your blind spot could result in an accident. You must check here to make sure you eradicate the risk of pulling into someone. If you don't check your blind spot before moving off, the examiner may consider your driving to be dangerous and you may fail your test.
Before moving off you should do your safety checks. Use your mirrors and check your blind spot over your right shoulder last. (left shoulder if you're pulling away from the right hand side of the road). The Official DVSA Guide to Driving - The Essential Skills.
WHICH AREA SHOULD YOU CHECK LAST?