Grey fleet: when staff
drive their own cars for work.

Grey fleet is the industry name for privately owned vehicles that employees use for work journeys. The estimator driving to a site visit, the office manager collecting a delivery and the director meeting a client in their own car are all part of it. HSE’s guidance is clear that these vehicles are the employer’s concern. Privately owned vehicles used for work must be safe, and the worker must check them, have them serviced, and have insurance and a valid MOT.

Why grey fleet is easy to miss

A company van has a register, a service schedule and somebody responsible for it. A private car has none of that from the firm’s point of view. Nobody in the office knows when its MOT runs out, whether its tyres are legal, or whether its insurance covers business use. The firm only finds out when something goes wrong on a work journey.

The duty does not change with ownership. HSE’s guidance says health and safety law applies to work on the road as it does on a fixed site. It asks employers to make sure licences, insurance and MOTs are legal and up to date for everyone who drives for work. A car on an employee’s driveway is still a work vehicle while it is on a work journey.

Insurance for business use

Every vehicle on the road must be insured, at least against injury or damage to a third party. The question for grey fleet is what the policy covers. GOV.UK tells drivers to tell the insurer whether the vehicle is for social or business use, because it affects the policy. A car insured only for social and commuting use may not be covered for a journey to a client or a site.

The Highway Code adds a second risk: driving an unroadworthy vehicle may invalidate the insurance. A private car with a bald tyre on a work journey can leave the driver uninsured and the firm exposed.

The car is the employee’s. The journey is the firm’s.

What the employer should check

A grey fleet policy normally asks for the following, before anyone drives for work and then on a fixed cycle:

• Driving licence. Held, valid for the vehicle, and any points or restrictions declared.
• Insurance. A certificate showing cover for business use, for this driver and this vehicle.
• MOT. A valid certificate where the car needs one. GOV.UK says an MOT can be done up to a month, minus a day, early and keep the same renewal date.
• Road tax. In date.
• Servicing. Serviced to the manufacturer’s schedule, as HSE’s guidance expects.
• Condition. Checked by the driver before work journeys, with defects put right before the car is used for work again.

Each item has an expiry date, and that is where grey fleet records fail. A copy of a certificate taken in January says nothing in October. The record has to hold the dates and prompt somebody before each one passes.

What a grey fleet policy says

Grey fleet usually sits inside the firm’s driving at work policy, covered in driving for work. The grey fleet part typically sets out:

• Who may use a private car for work. And for which journeys, such as site visits and client meetings, as opposed to carrying tools or materials.
• The documents required. Licence, insurance with business use, MOT and tax, and how often they are seen again.
• Checks and defects. The driver checks the car before work journeys and does not use it for work with a defect.
• Phones, hours and breaks. The same rules as any other work driver.
• Mileage and expenses. How business miles are recorded and paid.
• Incidents. How a collision or near miss on a work journey is reported to the firm.

Mileage payments

Firms usually pay employees for business miles in their own cars. HMRC sets approved mileage allowance rates. For cars and vans the rate is 55p a mile for the first 10,000 business miles in a tax year, up from 45p before 6 April 2026. Above 10,000 miles it is 25p. Payments up to this approved amount can be made without reporting them to HMRC. The rules sit in GOV.UK’s guidance on business travel mileage, and a mileage log for each journey is the evidence behind each claim.

That log does a second job. A record of who drove where, in which car, is also the record that shows which private cars are in the grey fleet and how much they are used.

When a company vehicle is the better answer

Some firms move high-mileage drivers out of the grey fleet into pool cars or company vans, because the firm then controls the vehicle’s age, condition and maintenance directly. Whether that is worth it depends on the miles, the work and the cost. Either way, the same three records apply: the driver, the vehicle and its dates, and the checks.

For company vehicles, the free daily vehicle check sheet, vehicle inspection checklist and vehicle maintenance log cover the records, and daily vehicle checks explains how the driver’s check and the office inspection divide the work.

This is general guidance, not legal advice. Check insurance cover with the insurer, and tax treatment against HMRC’s guidance.