if and when
At the time something happens, if it ever happens or comes to pass at all. Well, we should only worry about them if and when they become a real threat to the business. If and when any such law is passed, our firm will be ready to assist all citizens comply with the changes.
ˌif and ˈwhen
used to say something about an event that may or may not happen: If and when we ever meet again I hope he remembers what I did for him.