Yes, as long as they are named on the booking and pass the same age and licence checks as the main driver. Anyone who drives the car without being named is not insured.
Adding a driver
Add them at checkout or contact us before the hire. See can I let someone else drive the vehicle.
Their cover
Named drivers have the same cover and excess as the main driver.
Unnamed drivers
If an unnamed driver uses the car, the insurance is void and you are responsible for all damage and costs. See what is considered negligence.