Don, Tom, Arvi

thank you very much for your incredibly quick and helpful responses. The
"faster formula" from Tom and the solution from Arvi both work. Tom's
solution *does* appear to be quicker as you can see the SUMPRODUCT
calculation "ripple down" as you drag the formula down the column.

Don ... worry not, no need to send the file now. Thanks.

Regards

Trevor


"Trevor Shuttleworth" wrote in message
...
I'd be grateful for your assistance please. I think I should know how to
do
this, but I don't. Hopefully you can save me a lot of time.

I have a column (A) on one sheet, "Summary", which contains dates, April
2003, May 2003 and so on. The cells actually contain 01/04/03, 01/05/03,
etc. (UK date formats)

On another sheet, "Solutions", there is a column of Invoice Dates (D) and
a
column of Invoice Values (F).

In column C on the Summary sheet, I want to subtotal the Invoice Values on
the Solutions sheet where the Invoice month and year match the month and
year in column A on the Summary sheet.

I think I should be using SumProduct or an array entered formula but I
can't
quite get my head round it.

I appreciate your help, thanks

Trevor