Can you Insure yourself to drive a car you don't own ?

[Igovernor]

and I thought you were just a computer nerd

If you have fully comprehensive insurance yourself then you are covered to drive another car but only on third party cover. As for your original question
Yes you can insure your moms car you do not have to be the owner or registered keeper, I have done that many times. What you can do is one of two things
1 ring the insurance company and add your name to your mams policy
2 ring up the insurance company and tell them you want to take out a policy in your name on your mams car.

[GL1Blue]

If you have fully comprehensive insurance yourself then you are covered to drive another car but only on third party cover. As for your original question
Yes you can insure your moms car you do not have to be the owner or registered keeper, I have done that many times. What you can do is one of two things
1 ring the insurance company and add your name to your mams policy
2 ring up the insurance company and tell them you want to take out a policy in your name on your mams car.

Double check on this one. Not all companies give third party insurance for other cars with a comprehensive policy anymore. It was an additional, albeit small, charge on mine.

[Igovernor]

If this is not on your policy
"The policy holder may also drive a vehicle with the permission of the owner of a motor car not owned by the policy holder and not hired to him/her under a hire purchase agreement." Provided that the person driving holds a licence to drive the vehicle or has held and is not disqualified from holding or obtaining such a licence, and is driving on the policyholders order or with his permission’

Provided that the person driving holds a licence to drive the vehicle or has held and is not disqualified from holding or obtaining such a licence, and is driving on the policyholders order or with his permission’

If your Certificate does not contain this phrase, you are not insured to drive other cars.
you are not covered to drive any other cars unless the car you are going to drive has an any driver policy or you are a named driver on the policy"

[valleys caveman]

Double check on this one. Not all companies give third party insurance for other cars with a comprehensive policy anymore. It was an additional, albeit small, charge on mine.

Mine doesn't.