ADVANCED: Extracting Unique Records

At the moment i am having great trouble taking two sets of records, comparing the two based on certain criteria and then extracting any records (rows) that do not appear twice, that is unique records.

So here it is:

I have two lists of sales.

1. our list from our point of sale system with order numbers and other details, entered by the sales agent.

2. the company that provides the products we sell for them sends us a list of these sales back to us from their end so we can see outcomes of these sales, that is the progress of the order, like cancelled, accepted, etc

The two lists need to be compared to see what sales are missing from either one..

so, I could colour the second list RED and the first list GREEN and add the second list underneath the first list (on the same sheet) and then sort by ORDER NUMBER, which would provide a red, green, red, green, red, etc pattern and i could easily identify sales that are unique, but there are so many thousands of sales this manual process is impossible.

IS THERE A WAY TO AUTOMATICALLY COMPARE THESE TWO LISTS BASED ON ORDER NUMBER AND SHOW ONLY THE RECORDS THAT ARE UNIQUE? THAT IS, GET RID OF SALES THAT APPEAR TWICE AND LEAVE ONLY RECORDS THAT I HAVE TO LOOK INTO WHY THEY ARENT ON BOTH SALES SHEETS...

Here is an example of the data i am using:

ORDER #
1630923-
1634849..
1634849..
1634972+

the numbers do NOT have the .. - or + next to them, thats just there to show you what list each is from.

so as you can see the order numbers with ".." next to them are reconciled, in that they have a partener record and do not need to be shown at all..

and the order numbers with "-" next to them are from our list

and the order numbers with "+" next to them are from THEIR list

i want to end up with a list like this:

ORDER #
1630923
1634972
1635643
1641970
1648112
1649716
1653854