Sum Rows Recursively - Based on Another Column

[alex0182828]

I am trying to work out a formula to populate column D ie to add up the all the orders for that customer for the month ( the period of the data in the spreadsheet ).

Just got no idea where to start.

Any help would be great.

 

[VoG]

Try in D2 copied down

=SUMIF(A$2:A$100,A2,C$2:C$100)

 

[alex0182828]

So simple ! Amazing thanks for the help.

Alex