Can I use proof of no claims discount from a Company Vehicle?

We currently allow a discount from company vehicles where we are supplied with a letter from the employer stating the following:

• How long the regular driver was insured by the company
• Full details of accident, claims and loss history
• That the regular driver had sole use of the vehicle including personal usage
• The regular driver must no longer have use of the company vehicle for the discount to be applicable
• The maximum proof we can accept from a company is 5 years
• You will need to send us proof of your no claims discount within 7 days for a car insurance policy and 7 days for a van insurance policy of your policy start date. If you do not do this the cost of your policy will increase or, in some cases, be cancelled.