But if the value for column 9 is blank, then I want blank returned.

Currently Excel is populating the value of "1/0/00"

I am struggling with fitting an ISBLANK condition into this formula.

Can someone please assist?

=IF(D247<>"",D247,IF(ISERROR(VLOOKUP(O247,'G-Block CMO-FMO and IP Ranges '!$A$61:$I$400,7,FALSE)),"",VLOOKUP(O247,'G-Block CMO-FMO and IP Ranges '!$A$61:$I$400,9,FALSE)))