Try...

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

Hope this helps!

In article ,
Steved wrote:

Hello from Steved

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

from this 'From Charters'!$I$1:$I$898) to'From Charters'!$I$1:$J$898)
gives a #VALUE!.
Basically i'm trying to sum 2 cells Charters'!$I$1:$I$898 and
Charters'!$J$1:$J$898
Thankyou.