Merge Duplicate Contacts (Lightning)
If you have NPSP installed, the best way to merge contacts is by using the 'Contact Merge" application available as part of the NPSP. If you do not have NPSP installed in your instance of Salesforce - you can merge contacts using either the 'classic' method detailed in this article.
or by Following the instructions to set up matching and duplicate rules shown in this article.
Here's how to merge contacts in Lightning using the Contact Merge app.
Check the profiles of your duplicate contacts and decide which to make the 'master' record
Look at the duplicates you wish to merge, and see if any HandsOn Contact Profile. (i.e. "Volunteer", "Volunteer Leader", "Partner Staff" is assigned to any or all of the contacts.
Decide which contact you want to make the "Master" contact after the merge. Remove profiles from the other contacts BEFORE you merge. You can do remove a profile by selecting "Change profile" and then selecting "None".
Launch the Contact Merge App from the app launcher
Click on the 'waffle" icon (upper left), and type in "Contact Merge", then select "Contact Merge"
Choose "Search Contacts"
If you have defined matching rules, you can click on "See Duplicate Contacts" - but generally its easier to just click on Search Contacts
Type in the contact name in the Search contacts Box and click "Search". Choose up to three contacts you wish to merge and click on next.
Choose the 'master' contact and select field values you wish to preserve
Choose the master (winning) contact. This is the contact that the other(s) will be merged into. Your master contact should be the one that has a HOC profile. (If neither have a profile, you can choose either as the master contact).
The other contact records will be deleted after the merge. Use the "Select All" button to initially select all the values in that contact. And then scroll down to the page, field by field, selecting any values from the non-master record(s) that you wish to be populated in the merged contact.
After selecting all the values to incorporate in the merged contact, click Merge.
After clicking on merge. Only one contact will remain, and any Household for the deleted contact will be deleted UNLESS that Household has more than one contact associated with it. (I.e. it's a family with muiltiple contacts associated as members of the household). In that case, the household will be disassociated from the deleted contact, but the household record will remain and be associated with the other family members.
All Connections, Team memberships, and other related objects will be merged into the newly merged contact -- so no data related to the deleted contact will be lost.