This is despite more and more businesses requiring their company car drivers to undergo additional training.
The action has been prompted by proposed laws on corporate manslaughter, which could mean a company's directors being held responsible for a death caused by an untrained driver employed by them.
PHH - which manages more vans than any UK company – calculates that, of the 2.17m vans on British roads, more than 1.6m are driven by people with no training beyond that for driving a 3dr hatchback.
Since 1992, more van drivers have been killed or seriously injured than bus, coach and HGV drivers combined, according to Department of Transport figures.
High staff turnover among van drivers makes companies understandably reluctant to provide training.
But Barry Chaplin, director of sales at PHH, said: “Vans are not cars and those who drive vans on a regular basis need to be given the right kind of training.”