Customers often interact using different email addresses — personal, work, checkout…

Traditionally, this creates duplicate profiles, broken journeys, and inconsistent consent data.

We now support Multi-Email Profiles, where up to 5 email addresses will be maintained per profile.

How Klaviyo Chooses the Primary Email

Logic

Step #1 Check Consent: Klaviyo picks the email that can actively receive marketing — the one that’s opted-in or subscribed.

Step #2 Activity next: If several emails have consent, the one tied to the most recent Placed Order or non-bot Email Click becomes the Primary.

Step #3 Fallback: If there’s no clear consent or engagement signal, we use the most recently added email to keep things fresh.

Real-Time Triggers (within ~1 hour)
- A new email is added to the profile
- The current Primary Email unsubscribes, bounces, or is removed
Nightly Validation
- Every 24 hours, Klaviyo re-checks all profile emails to confirm the correct Primary is still active.

Klaviyo merges profiles when it can tell they represent the same person based on shared identifiers such as:

External ID

Klaviyo merges into a profile, called the destination profile. This profile retains its Primary Email and identities.

The other profiles are merging into the destination profile adding their:
Additional emails
Profile properties
Event history and activity
Consent and suppression records (Each email still keeps its own consent and suppression status.) Default Behavior

Flows, Segments and Campaigns Send to the Primary Email on the profile.

Send the email tied to the event itself. Example: Abandoned Cart → sends to the checkout email.

If that event email becomes unsubscribed or unreachable, Klaviyo skips the flow (doesn’t fallback to Primary).

Send to the email captured at list signup.

If no list email is stored → fallback to Primary Email.

When profiles merge, list membership and email context are preserved.