Annual car hire excess insurance is a form of car excess insurance whereby you can take multiple trips (or rentals) under the same policy during the term of a year. Grouping your car rental excesses under the one policy means you get better rates than on individual trips but with the same level of cover.
Under the annual cover you can claim an aggregate limit of £10,000 during the policy term although this type of cover is not available for business use and can use the policy for car rentals of less then 62 days at a time although you can take as many rentals as you need.
If your question isn't answered here you may want to checkout these pages: