Not really a single authority at all, but created by BUBO Listing for those listers who prefer the BOU list, but wish their list to apply over both Britain and Ireland.
This list is effectively the BOU list, plus any further species that have been accepted by the Irish Rare Birds Committee. The list maintained by the Manx Ornithological Society is also considered, although at the present time there would be no additional species added as a result. The Channel Islands are not included within this list.
Species currently considered as comprising the Britain and Ireland List for BUBO Listing purposes are shown below