Fleet managers picking repair firms are taking "pot luck" and risking dangerous repair quality, according to RAC Services.
The comment comes following a Metropolitan Police initiative to investigate the ability of bodyshops to repair the "ultra-high strength steel" components in modern cars.
Former Cheshire assistant chief constable, John Dwyer, has claimed that fewer than a quarter of the UK's 5,500 garage bodyshops are equipped to repair cars containing the new high strength steels.
Phil Mairs, head of RAC Services, says: "There is a varying standard of skill and quality among the damage repair industry and fleet managers are taking pot luck by choosing a repairer from a phonebook.
"Fleets can't be expected to know how to vet a potential repairer, which is why it's essential to tap into an approved repairer network.
"Those buying repair services should be looking for the BSI PAS 125 Kitemark for vehicle body repair. Developed by BSI and Thatcham - the Motor Insurance Repair Research Centre - the standard covers five key elements of the repair process, including people, methods, equipment, materials and process management."
