The list of British Birds maintained by the British Ornithologists' Union. Generally held to be the 'official' list for British birders, albeit the most conservative one. If you have no strong opinions on list authorities, it is recommended that this is the one you use.
Within BUBO Listing, the BOU authority can be used for lists in Britain, the constituent countries of England, Scotland and Wales, and smaller units of Britain such as counties. Note that the BOU List does not apply to Ireland (but see the 'Britain and Ireland' authority).
The latest updates of the BOU list included within BUBO Listing are the 41st report of the BOU Records Committee, as published in the journal Ibis. The report added Scopoli's Shearwater and removed Madeiran Storm-petrel from Category A of the British list, the latter following the splitting of this into several species which are currently unidentifiable in the field.
Note also that many recommended changes to the systematic order of species have now been implemented, despite the confusion this may cause. The most recent update makes many changes, in particular, to the sequence of the waders.
Note that BUBO Listing also includes six more 'provisional' species not currently recognised as occurring in a wild form in Britain by the BOURC: Lesser Canada Goose, White-winged Scoter, Slaty-backed Gull, Elegant Tern, Alder Flycatcher and House Finch.
Species currently considered as comprising the BOU British List for BUBO Listing purposes are shown below. Please note that any comments shown are those of BUBO Listing and are not necessarily endorsed by the BOU.