if and when

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.
See also: and, if
Farlex Dictionary of Idioms.

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.
See also: and, if
Farlex Partner Idioms Dictionary
See also:
  • if anything happens
  • (some) time (a)round
  • a one-off
  • cross a bridge when one comes to it
  • cross a bridge when you come to it
  • cross that bridge when (one) comes to it
  • cross that bridge when (one) gets there
  • cross that bridge when (one) gets to it
  • cross that bridge when one comes to it
  • cross that bridge when you come to it