I have a large list of information. One of the columns is a list of
customers. In this list a customer will be isted multiple times, with
different information listed in the other columns. One of the other columns
is a date. For each customer I need to know that I have recieved data in one
of the rows for each month. Is there anyway to look through a list using on
columns as being "unique" in this case the customer and for each of the
unique listings making sure we have each month listed?

What happens is we get paid per month for each customer and we want to audit
the list to make sure we are getting paid for each month. We can do it
manually but it is very time consuming.

Any help will be greatly appreciated.

Cindy.