This article is about understanding how Loopify recognizes unique and duplicate contacts when new contacts are added to an account. It will help in understanding when will a contact be recognized as an existing (duplicate) and when it will not.
New contacts in Loopify can arrive from several places: in the Contacts app by adding a single one or importing a contacts file; submitting their info on a Loopify Page; importing a file through a Flow and through the API entry in Flow.
It is very important to know the three unique contact-identifiers in Loopify, in this following order:
External ID, Mobile, Email.
The ExternalID is a default Loopify field with the purpose to externally identify your contacts in a way you see fit. The ExternalID contact field is the "strongest" in uniqueness. What this means is that when a new contact arrives to the account, it will first be cross-checked with other contacts whether a contact with the same ExternalID already exists. If it doesn't - the arriving contact will be added as a new contact. If that ExternalID does exist on a contact - the already-existing contact will be updated. This is of course, only valid when you choose to update existing contacts on import and not keep them unchanged.
Example 1: You have an existing contact called John Doe with the number 100 as an externalID. You're importing a new contact Jane Doe with the number 100 as an externalID. Loopify will recognize that this externalID already exists, so it will update John Doe to Jane Doe.
Example 2: You have an existing contact called John Doe with the number 100 as an externalID. You're importing a new contact Jane Doe with the number 200 as an externalID. These externalIDs are different, resulting in two different contacts.
Note: This does mean that you can at the same time have two or more contacts with the same mobile and email address, as long as they have different externalIDs.
If the contacts have no externalIDs at all - then it's the Mobile's turn, and the same rule follows. When adding new contacts, it will be checked whether a contact with that mobile number already exists. If it does - update it. If it doesn't - add it as a new one (regardless of the email address).
If contacts have no externalIDs or mobile numbers, then it's the email's turn. Again, the same rules apply.
Here's a more advanced example for your thinking pleasure!