What happens if you fail to SORN your car?
If you fail to do the proper paperwork then you can be liable for an £80 fine and you must pay any tax arrears as the car will effectively be back on the road with no tax. Tax rules mean that the responsibility to prove it is not on the road lies with you. Nobody needs to spot you driving your car in the local high street, if you haven’t declared it off the road then that is all that matters.
You could also end up with a £1,000 fine to pay and with a County Court Judgement (CCJ) against you, so it can have serious consequences.
If you want to tax your car and you don’t want to renew the SORN, you will need a new MOT certificate. In fact, the only legitimate reason for putting a vehicle with a SORN on the road is to drive it to a pre-booked MOT, when you are preparing to get its paperwork back in order.