Beginning with 1947, the British Library has a complete set of registers for the United Kingdom (England, Scotland, Wales and Northern Ireland). A complete list of their holdings is in a publication titled, Parliamentary Constituencies and Their Registers Since 1832, which also includes earlier burgess rolls and poll books. Once in hard copy, it can now be downloaded at www.bl.uk/reshelp/finhelprestype/offpubs/electreg/parliamentary/constituenncies.html.Because of concerns about identity theft and commercial use of the lists, restrictions apply to the electoral registers from the past ten years.
Having voting information after 1832 is not always helpful to American genealogists because it is just too late. Locations of earlier records can be found in the following pamphlets:Gibson, Jeremy and Colin Rogers Gibson. Poll Books c. 1696-1872, a directory of holdings in Great Britain. Birmingham, UK: Federation of Family History Societies, 1994.
Gibson, Jeremy and Colin Rogers. Electoral Registers since 1832and burgess rolls. Birmingham, UK: Federation of Family History Societies, 1990.Check on purchasing copies at www.ffhs.org.uk. Even the British Library states that if the early roll you need is not listed in one of the above, “it may well be that no copies of the register sought survive.”