Comparing sheets

Closed
Report
-
Hello,

I need help comparing data in Excel 2007. Here is the situation, I'm using an aging report and in sheet 1 column A I have the invoice numbers. Basically on Sheet 1 I have been trying to collect the past due invoices. Sheet 2 is the new aging report that comes out every Monday. There are about 450 rows so manually comparing each row is out of the question.

I need to compare Sheet 1, Column A to Sheet 2 Column A to see if the match. If there is new data in sheet 2 column B I would like it to then add to Sheet 1 column A.

My goal is basically to have a revolving master sheet (sheet 1) and add or subtract to it as needed.

any help is greatly appreciated.