How to highlight Unique values between two sheets

[Dark0Prince]

I have client numbers on a sheet called ABQ_IMPORT in the A Column and I need to see if they exist in the sheet i have called 2018 in Column B. If they do not exist on the 2018 sheet I need something to happen to notify end user like a conditional formatting to tell user that it doesn't exist.

 

[Fluff]

How about, with CF
=ISERROR(MATCH(A1,'2018'!$B:$B,0))

 

[Dark0Prince]

Perfect

 

[Fluff]

Glad to help & thanks for the feedback