Best way to match up two lists

[skygirl]

I have a workbook with monthly account lisitngs. Each month is on a seperate worksheet and the customer lists are simelar. I need to compare the two lists - match up the numbers for each identical customer name and identify any rows that are on one month's report but not on another. Any suggestions?

 

[PaddyD]

a variety of techniques here:

http://www.cpearson.com/excel/duplicat.htm