This is all totally new to me and I am lost.
Car was due to be taxed at beginning of July
Car was booked in for MOT end of June
Car had accident before I could have it tested.
Car has been of the road ever since waiting for spare parts.
SORN has been applied for by post.

So what happens if the repair garage finally finishes with the car. (I have already had the date of the test changed 3 times every time they told me it would be ready in a few days. In fact I missed changing the last date so have now forfeited the £30 cost.)

My understanding is I may only drive the vehicle on the road to an mot appointment providing I have valid insurance which i of course have.

How do I collect it from the repair garage to keep it off road at home while I wait to have it tested ?

Paranoia rules