Klaviyo duplicate profiles, merge profiles and duplicate emails before import

Klaviyo identifies a person by email address, phone number and, on iOS, a device ID. When an event carries two of those together, a checkout with an email and a phone number or a signup form with both fields, Klaviyo links them and keeps one profile. When a person arrives through a channel that carries only one identifier, it has nothing to link, so it creates a second profile.

Klaviyo's own help center gives the common case: a customer with an email profile who later subscribes to SMS through a keyword opt-in ends up with a separate phone profile. The same thing happens when a shopper checks out with a work address after signing up with a personal one, and when a list from a previous email platform is imported with addresses or phone numbers that do not match the profiles you already hold.

Merging does not always stick either. Klaviyo documents that if a source profile is merged into a destination and an event later arrives with the source profile's old email address, a new profile is created for it. A cleanup that only happens inside the account keeps coming back as long as the files you feed it carry the old identifiers.

Yes, but only on a shared identifier. Klaviyo merges profiles automatically when an event links an email to a phone number, and when two profiles carry the same external ID, such as a store customer ID. It does not merge two profiles because the names match, and it does not suggest near matches for you to review.

Klaviyo now also supports multi email profiles, up to five addresses on one profile, combined automatically when the profiles share an external ID. That helps brands whose store sends a customer ID with every event. It does nothing for a keyword SMS signup or an imported list that has no external ID column, which is where most duplicate profiles in a growing account come from.

Klaviyo bills on active profiles: profiles that can receive at least one type of marketing, meaning they have a valid email address or phone number and are neither suppressed nor deleted. An email profile and a phone profile for the same shopper are two billable profiles. So are the work and the personal address of one customer, unless an external ID has folded them into one profile.

When the active count passes your plan threshold, Klaviyo notifies you and moves the account to the higher tier as of the next billing cycle. Going back down is not automatic. Once the count falls below the threshold you become eligible to downgrade, but you have to do it yourself, more than 24 hours before the billing cycle turns over, and after bulk deletes or suppressions the count can take up to 72 hours to refresh. A large import full of duplicates can decide your next invoice before anyone notices.

For one or two, search the profile by name in the Profiles view and open each result. For more than a handful, export all profiles into one file, because duplicates that share no identifier only show up side by side, sorted by last name. To export everyone, create a segment that contains all profiles, then export that segment with the properties you need.

Look for pairs where one row has an email and no phone number and the other has a phone number and no email, especially where the source is an SMS keyword or a pop up. Those are the duplicate profiles Klaviyo cannot link by itself, and they are also the ones that cost you twice.

On a CSV import Klaviyo looks for an existing profile with the same email or phone number and overwrites any property you include with the value from the file. That is useful when the file is better, and quietly destructive when it holds a lowercase name, a state written as texas or a ZIP code that lost its leading zero in Excel, because every segment built on those properties now misses the row.

So the same pass that finds duplicate profiles also repairs formats before the import: names in consistent case, emails trimmed and lowercased, states as two letter codes, ZIP codes back to five digits and dates in one format. Doing that on every incoming list is the routine side of data hygiene, and it keeps the cleanup from being repeated every quarter.

The buyer is usually the email and SMS lead at a US ecommerce brand, or the agency running Klaviyo for several stores, who owns the Klaviyo invoice and is about to import a list, switch on SMS or move a subscriber base over from another platform. They need the profile count to stay under the next tier and to be able to show why it moved.

Brands that sell to businesses carry the same problem one step up, in the CRM. If your Klaviyo profiles are fed from a CRM export, cleaning the CRM once, as described in CRM data cleansing, means every future sync starts from one record per person.

A pass on the export fits a project: an import to run, an SMS launch, a tier you want to stay under. A person reviews every merge and applies the result, and that is deliberate, because deciding whether two profiles are one shopper belongs to someone who knows the customers.

If you need profiles merged continuously inside Klaviyo without an export, look at your store integration first, since sending an external ID with every event lets Klaviyo merge on its own. DataUntangler does not connect to your Klaviyo account and does not claim to. It is a data cleaning tool that gives you the matched file and a record of each decision, on the Analyst plan at 59 dollars a month with unlimited files. For lists that go into Constant Contact instead, the same pass is on Constant Contact duplicate contacts.