Thank you. I don't want to breed - but have kept males and females together in the past with no nest box and no babies either.
Phil (lone bird!) is at mum and dad's so I'd probably get the new bird(s) and keep them here in the new cage until quarantine period is over. Are even numbers always better then? When mum and dad had three birds they didn't seem to have any major problems - Lil (the girl - bossy boots) went off playing and the boys sat and chirruped together lol.