Klaviyo integration: API key auth, lists + segments, profile data preserved

Klaviyo is API-key authenticated. The flow: generate a Private API Key in Klaviyo, paste it into our dashboard, pick a list or segment, verify. Profile properties, event history, and predictive analytics data are unaffected by any cleanup actions.

Where to find your Klaviyo API key

1. Sign into Klaviyo.
2. Open Account → Settings → API Keys (or navigate via your account avatar → Settings → API Keys).
3. Click Create Private API Key.
4. Give it a recognizable name (e.g., "Valid Email Checker").
5. Select scopes: at minimum Profiles: Read/Write and Lists: Read. For cleanup actions, also add Profiles: Write access.
6. Copy the generated key (pk_xxxxxxxxxxxxxxxxxxxxx).

Connecting Klaviyo

1. In our dashboard, go to Bulk Upload → Connect Email Platform → Klaviyo.
2. Paste the API key into the form.
3. Optionally name the connection.
4. Click Save Connection. Your Klaviyo lists and segments sync automatically.

What you can verify

• Lists — manually created or imported subscriber groups.
• Segments — dynamic, filter-defined groups (e.g., "Engaged 90 days", "Active customers").
• Both show subscriber counts so you can size the verification job in advance.

For ongoing hygiene, verifying a segment like "All active profiles" or "Profiles created in last 30 days" is more cost-efficient than verifying every profile in your account every time.

Clean-list defaults

Same defaults as all other integrations: Invalid (Unsubscribe) and Disposable (Delete) enabled by default; Catch-all, Unknown, Risky disabled. See the integrations overview for the full table.

In Klaviyo, Unsubscribe sets the profile to "Unsubscribed" status (removed from marketing sends but retained for transactional and analytics). Delete removes the profile entirely — note that Klaviyo retains some metadata for analytics purposes even after deletion.

Common Klaviyo issues

"API key not authenticating"

• You pasted the Public API Key instead of a Private one. Public keys cannot read profile lists.
• The key has insufficient scopes. Make sure it includes Profiles Read/Write and Lists Read.
• The key was revoked or has expired. Generate a new one and re-connect.

"Cleanup did not update all profiles"

Klaviyo's API has rate limits that throttle bulk writes. For very large lists, cleanup writes are queued and processed over several minutes. If updates seem stalled after 10+ minutes, contact support — we can check the API response log on our end.

Cost

1 credit per profile verified. Verifying a 100,000-profile list costs up to 100,000 credits (less, after duplicates and unknown-refunds). Most Klaviyo accounts benefit from monthly verification on a smaller "engaged in last X days" segment rather than full-list checks.

Next steps