How to Connect Klaviyo
Connecting Klaviyo lets you send your segments to Klaviyo, and brings your Klaviyo email and SMS results into By the Numbers. Only customers who agreed to email marketing in Shopify are sent. You connect by signing in to Klaviyo and approving access; there’s no API key to copy.

Before You Start
- You need a Klaviyo login for the account you want to connect.
- You need the Manage integrations permission in By the Numbers. Without it, the Klaviyo card shows no Connect, Configure or reconnect button, and no menu.
Steps
- Open Integrations: Integrations, under Settings in the navigation.
- On the Klaviyo card, click Connect.
- Click Connect with Klaviyo. Your browser moves to Klaviyo.
- Sign in to Klaviyo and approve access.

What Happens Next
Klaviyo sends you back to Integrations, which shows Klaviyo connected. The card moves to Connected and names the Klaviyo account it’s connected to.
- Segments: you can now sync any segment to Klaviyo. See How to Sync a Segment.
- Pulse: the Klaviyo Email & SMS row shows Klaviyo Revenue, Avg Open Rate and Avg Click Rate. See Pulse.
- Klaviyo Performance: a report with the revenue, opens and clicks for your campaigns and flows. See Klaviyo Performance.
By the Numbers reads your Klaviyo results once a day: see How Often Is My Data Updated?.
Which Customers Are Sent
A customer is sent when both of these are true:
- They have a valid email address.
- They accept email marketing in Shopify.
A customer who hasn’t agreed isn’t sent at all. When a sync leaves customers out, its line under Recent Activity on Integrations says how many, for example 40 skipped (no marketing consent).
A customer who stops accepting marketing isn’t sent again. Nothing already in Klaviyo is deleted or unsubscribed. How to Sync a Segment says what happens to them on each kind of connection.
Phone Numbers
Segment syncs send email addresses and names, and leave phone numbers out. To send phone numbers too, for SMS:
- Click Configure on the Klaviyo card. If the card is under Needs attention, click Details instead.
- Turn on Include customer phone numbers in syncs.
- Click Save.
The next sync of each segment sends the phone numbers. Only numbers that are valid mobile numbers for the customer’s country are sent, and a number Klaviyo has refused before isn’t sent again. A number goes with each customer who is sent, and By the Numbers doesn’t check their SMS marketing consent.
If the Card Asks You to Reconnect
If the card shows Reconnect needed, Klaviyo no longer accepts the connection. Click Reconnect and approve access in Klaviyo again.
Older Klaviyo connections don’t have permission to read email and SMS results. Their card on Integrations shows Performance Data Disabled. Your segment syncs keep working either way.
To give the extra permission:
- On Integrations, click Reconnect to Enable Performance Data on the Klaviyo card.
- In the Reconnect Klaviyo dialog, click Reconnect with Klaviyo, then approve access in Klaviyo.
To disconnect Klaviyo, choose Remove from the card’s menu. This also removes every segment sync to Klaviyo, but leaves the lists in Klaviyo as they are.