Here is the article on how to do this in Act!, and you can only merge two contacts at a time.  If you want to do this en masse, you need Duplicate Merge Wizard instead.    Here is what’s cool about this plugin.

  1. It will merge the contacts without going through the arduous 7 step wizard
  2. You can use up to 7 criteria to match duplicates
  3. When contacts merge, it will merge the notes, history, activities and opportunities; then, add notes to the new merged record that tell you the historical contact field data.
    Here is what happens:
    For example: The program merges Contact A with phone number 312-555-1234 and Contact B with 312-527-3133 to have Contact A with phone number 312-555-1234. Contact B is gone.
    Contact A has the notes from A&B.
    Contact A has a note in Act! now, “Merged Phone Number from Contact B of 312-527-3133”.
    So you don’t lose the historical information from the merge.  The merge program decides whether A or B is the best record by the most recent edit date.

The Duplicate Merge Wizard offers a trial version of their software.

Quick video (No Audio) on the steps in Act!

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