« Reply #8 on: Wednesday 12 March 25 18:53 GMT (UK) »
This one does seem to be qualifying date June and coming into force in October 1948.
I was recently looking at electoral registers in Cromer, Norfolk, in 1966 and it says qualifying date October 1965 and coming into force in February 1966, so some electoral registers may vary. A friend of mine was born December 1944 and is listed in the Oct 1965 registers but with an asterisk next to his name, meaning he will be eligible to vote for the next years registers, as said in a note below. In Oct 1965 he was not yet 21. A few others the same age range (still must have been only 20 in Oct 1965) also had the same asterisk and note.
Researching:
LONDON, Coombs, Roberts, Auber, Helsdon, Fradine, Morin, Goodacre
DORSET Coombs, Munday
NORFOLK Helsdon, Riches, Harbord, Budery
KENT Roberts, Goodacre
SUSSEX Walder, Boniface, Dinnage, Standen, Lee, Botten, Wickham, Jupp
SUFFOLK Titshall, Frost, Fairweather, Mayhew, Archer, Eade, Scarfe
DURHAM Stewart, Musgrave, Wilson, Forster
SCOTLAND Stewart in Selkirk
USA Musgrave, Saix
ESSEX Cornwell, Stock, Quilter, Lawrence, Whale, Clift
OXON Edgington, Smith, Inkpen, Snell, Batten, Brain