VLOOKUP only returns a single value so you cannot sum. If I understand
correctly, you want to check column A (I assume formatted as DATE?) for month
in B2 and then sum values in column B

try:

=SUMPRODUCT(--(month(mid!A4:A400)=B2),B4:B400)

B2=8 (for August)

HTH

"George A. Jululian" wrote:

I need a VLOOKUP formula that to find August month in the column and to add
sum only August month in a sheet

In my formula B2 is the month I request MID is sheet I request to find
august month and add sum only August

=VLOOKUP(B2,MTD!A4:AZ400,2,FALSE)