Family visa any grace period to come to UK

Hi members,

My mate is getting his work permit stamped and is planning to come to UK end of March. Is there any grace period by when his family can join him? He was thinking of bringing him over to UK in Summer.

Is that possible or should the join him whilst he is coming over to UK end of march?

Thanks

They can join at any time. However, once their visa is issued, they have 30 days to enter the UK as this is the validity of the visa in their passport.

Thanks very much