This formula is also summing the the value above to give 2 totals.
 

Hello from Steved

'From Charters'!$F$1:$F$898,{"Contract Kilometres(Manuals)"} the below is
not reading hence it is totalling the cell above, Please what have I not done
correctly.
ie if I delete any part of Contract Kilometres(Manuals) it still calculates
the 2 cells.

=SUMPRODUCT(--ISNUMBER(MATCH('From Charters'!$F$1:$F$898,{"Contract
Kilometres(Manuals)"},0))--('From Charters'!$B$1:$B$898="Period.4"),'From
Charters'!$G$1:$G$898)
Thankyou.