We get a lot of calls for quick help on Excel and there are a number of regular questions. One in particular is identifying and getting rid of duplicate data.
Excel has a good feature on the Data ribbon – Remove Duplicates.
This allows you to identify which columns need to be matched ...
... and then the system will tell you how many rows have been found as duplicates and how many would remain.
If you were just interested in keeping one row for each, say, email address then this works perfectly.
Unfortunately this is not always the case and we often find that each occurrence of the duplicated data (e.g. email) has different data against it that then needs to be merged or prioritised. I'll add a couple of alternative for finding and managing duplicates at another time.