Anyone aged 12 years or over who fishes for salmon, trout, freshwater fish or eels in England and Wales is required by law to have an Environment Agency Rod Fishing Licence. Rod licences differ from permits (often referred to as tickets or day tickets) which give permission to fish a particular water or waters and are issued by fishery owners.
That is quoted on the Environment Agency website. My reading of that is that you need a licence- even if you are fishing in your own pond in your own back garden.
And you cant buy licences from the inspector!! Get them from the post office or on-line