Say Data in rows 2:101. Next to G you can enter the following formula:

=SUMPRODUCT((A$2:A2=A2)*(C$2:C2=C2)*(G$2:G2=G2))

Copying the formula down will start showing numbers greater then 1 as
duplicates start appearing. You can then filter on 1. If you want
Conditional Formatting select all cells A2:G101 and Formula Is:

=$G21

HTH
Kostis Vezerides

On Nov 25, 5:36*pm, Liz J wrote:
I'm looking at data for shipped quantity per order, and, it looks like some
of the data are duplicates. *I think the best way to find these duplicates is
by a conditional formula. * The hard part about this task is the amount of
orders. *I have approximately 4,000 orders to look at -- and I want to find
these duplicates by item, by customer.

Column A - customer name
Column C - item description
Column G - shipped quantity

I want to use a conditional formula that identifies customer name, item
description, and quantity, then highlights any duplicates (even if the
duplicate happens more than once). *Unfortunately, there is not a unique
number that I can use to distinguish one order for one customer and another
order for that same customer.

I would appreciate any help you can give me on this issue!

Thank you for reading my question! *