Licenses for fishing are pretty cheap and available over the counter at most larger Post Offices or online..There is no quota on them so you don't need to worry about there availability.

The only licenses a visitor needs to sort ahead of time is if they wish to import their own firearm or shotgun...If they are going to borrow a firearm/shotgun while in the UK, they can do so without a license as long as they are in the presence of the owner...