If you have information about a contact beyond their phone number, name, email, tags, etc.- you can add it to their Contact Details. Add these details through the Address Book or the collapsable contact sidebar in the Conversation dashboard.
Once you select the button to Show the Sidebar, select Edit to make any changes to that contact. Remember to click Save when you're done!
You can also update contacts individually through the Address Book by selecting View next to the contact you'd like to edit, or mass update your contacts by importing a CSV. The mass import will NOT duplicate existing phone numbers, but it will overwrite the contacts' current information with the information you provide in your spreadsheet.
Watch the tutorial video on Adding Contact Details here.
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