From February 1, all Category C repaired vehicles will have to be taken to one of the newly-established Vehicle Inspectorate centres for checks before the V5 document is issued.
Experts at Universal believe the extra paperwork and inspection needed before cars are allowed back on the road will wipe around £100 off the value of a Category C vehicle: the category where the repair cost exceeds the value of the vehicle.
Around 40% of the 470,000 total loss vehicles are in this category, representing about 180,000 written-off cars.
Martin Hynes, chief executive, said: 'The VIC scheme will make dubious practices more difficult and is a good thing but the knock-on effect on the industry cannot be underestimated. Among the implications we also expect to see resell values hit as vehicles will be stigmatised.'