The first time have all the workbooks open. Create a formula on your 'main'
workbook that references the other workbooks. Save and close all.
Next time you open your 'main' workbook, it will ask you if you want to
refresh the information coming in from the other workbooks. You can answer
YES or later in the session you can go to EDIT / LINKS / UPDATE NOW.
HTH,
Gary Brown

"rfhorn" wrote:

I have mutilpe workbooks (between 15 and 30) with similiar items in them. I
want to sum all the items in each workbook without having the individural
workbooks open at the same time, Is there any way I can add workbook data
together without have the workbook open?