Non-UK Residency
If you have not been driving in the UK for a number of years, and/or have a license from another country, you may face a higher premium. This is due to differing UK road laws, and the fact that most other countries drive on the other side of the road!

Also, if you have an International driving license, you can only drive in the UK for a year before this is either renewed, or you obtain a UK license (full or provisional)