Linking Klaviyo Profiles and LINE Friends by ID

ID linkage ties a Klaviyo profile and a LINE friend together as the same person, and setting it up correctly is the foundation of the Klaviyo integration.

What Is ID Linkage

ID linkage is the mechanism that ties a Klaviyo profile and a LINE friend in Lumo together as the same person.

The link is made using one of three signals: an email address, a phone number, or a LINE User ID. Once ID linkage is complete for a customer, you can use everything that depends on it: syncing profile data, sending LINE broadcasts from Klaviyo Flows, and recording LINE activity back to Klaviyo. Conversely, none of these features apply to customers who are not yet linked. ID linkage is the foundation you want to get right first in order to make the most of the Klaviyo integration.

Choose an ID Linkage Method

There are several ways to set up ID linkage, each suited to a different customer journey, so pick the one that fits your goal.

If you are unsure which methods to combine, ask the Marketing Agent, "Please help me set up the Klaviyo integration," and you can work out the approach that best fits your operations together.

Link from Email with a Custom QR Code

You can embed a per-customer linking QR Code in your Klaviyo emails and trigger ID linkage when the customer adds you as a friend.

When you set Klaviyo as the link type on a Lumo custom QR Code, you can tie an existing Klaviyo profile to a LINE user based on the email address. The setup steps are as follows.

1. Create a custom QR Code in Lumo, and under ID Linkage, choose Klaviyo Linkage as the Link Type
2. As the signal for linking, specify the Klaviyo merge variable that contains the customer's email address
3. Once you save the settings, a linking URL is issued, so reopen this screen to check the URL
4. Embed the issued URL or QR Code in your Klaviyo email and send it

When a customer who receives the email clicks the link or scans the QR Code and adds you as a friend, the matching Klaviyo profile and LINE user are tied together automatically based on the email address.

When the Linking URL Does Not Appear

The linking URL is issued after you save the settings. If it is not yet displayed, save once, then reopen the custom QR Code edit screen to check.

Link IDs from Form Submissions

You can trigger ID linkage by showing a LINE link button when a Klaviyo form is submitted.

You configure this under Link IDs from form submissions on the Settings tab of the Klaviyo integration. The steps are as follows.

1. Under Target Form, choose the Klaviyo form to use for linking
2. In CTA Label, enter the text to show on the link button (for example, "Link with LINE")
3. Add the Landing Page Embed Code to the landing page where the Klaviyo form is placed. This carries the form's submission details over to LINE linkage on the Success screen
4. Add a Button block to the Success screen of the Klaviyo popup form, and set the Success Screen Button URL in Go to URL

After setup, when a customer submits the form, the button on the Success screen switches to the linking display. On smartphones a LINE link button appears, and on computers a QR Code appears; when the customer adds you as a friend, ID linkage is performed based on the email address or phone number entered in the form.

How Mismatches Are Prevented

When both an email address and a phone number are available as signals, Lumo links them only when both match within the same profile. This mechanism prevents information from different people from accidentally being mixed together and linked.

Controlling Form Submission Timing with a Flow

If you want to control the timing of form submission with a Klaviyo Flow, use Linking Settings After Form Submission under Link IDs from form submissions. Create a Flow for the selected form, and set the Linking URL and Submission Details shown in the Webhook action.

Choose the Flow trigger to match your operations. To link immediately after the form is submitted, you can use Submitted Form; to link after double opt-in is completed, you can use Subscribed to List, for example.

When the Link Button Does Not Appear

If the link button does not appear after the form is submitted, check the following two points.

• Whether the Landing Page Embed Code is correctly added to the landing page
• Whether the Success Screen Button URL is set on the Button block of the Success screen

Link IDs from Flows

Triggered by an existing Klaviyo Flow, you can automatically match LINE friends by email address and set up ID linkage.

Under Link IDs from Flows on the Settings tab of the Klaviyo integration, check the settings for the Webhook action to add to your Klaviyo Flow. The steps are as follows.

1. Add a Webhook action to the Klaviyo Flow you want to use as the trigger (for example, a Flow that runs after double opt-in completes)
2. Choose POST as the HTTP method and set the Destination URL
3. Set the displayed Key and Value in the custom header
4. Paste the displayed content into the JSON body

The email in the JSON body is used to match a LINE friend, linking the Klaviyo profile and the LINE friend. To also match by phone number, add phoneNumber. Only friends whose email address or phone number is already known are linked.

This is handy when you want to reliably link customers who are already LINE friends at the moment of an email-driven action, such as a subscription or a purchase.

Link IDs From a Segment

If LINE User IDs are already stored in Klaviyo, you can read them and set up ID linkage.

You configure this under Link IDs from segments on the Settings tab of the Klaviyo integration. The steps are as follows.

1. Under Source Segment, choose the Klaviyo Segment that contains the profiles holding LINE User IDs
2. Under LINE User ID Property, select or enter the Klaviyo property where the LINE User ID is stored

Once you specify a source Segment, existing LINE User IDs are imported from Klaviyo every 15 minutes and tied to your Lumo friends. If you remove the specification, the import stops. This is handy when LINE User IDs are already managed in Klaviyo, such as during a migration from another vendor's tool.

Auto-Link by Email or Phone Number

ID linkage also happens automatically based on email address or phone number as part of normal data sync.

When LINE friend information is synced to Klaviyo, if a Klaviyo profile with a matching email address or phone number is found, it is tied automatically. The matched profile gets a LINE User ID written to it and is treated as the same person from then on. No special setup is required; this works automatically as long as the integration is enabled.

Import ID Links in Bulk

You can import LINE friend–Klaviyo profile links in bulk from ID links made with other tools or from a CSV file.

Under Import from a CSV file in ID link import on the Settings tab of the Klaviyo integration, upload a CSV file with two columns: email address and LINE User ID. The steps are as follows.

1. Drag and drop the CSV file (up to 50MB, with a header row on the first line), or upload it with Select file
2. In Email column and LINE User ID column, choose the corresponding CSV columns
3. Choose Start import

Imported links propagate to all connected integrations (Klaviyo, Shopify, and so on). After the import, you can review the per-row results on screen (linked, not a friend, invalid format, duplicate, failed). Only customers who are already LINE friends are linked, and rows for people who are not yet friends are not imported. If more people become friends later, run the import again to bring them in.

Automatically importing link data that another LINE integration tool stored on Shopify customers is done from the Shopify integration settings screen.

Check Linkage Status

You can check ID linkage status from the friend's detail screen and from Segment conditions.

On the friend's detail screen, you can check the linkage status under Klaviyo Sync Info, and open the profile on the Klaviyo side from View in Klaviyo.

When you want to filter customers by whether they are linked, use Segments. If you choose the condition Klaviyo ID Linkage when creating a Segment, you can pull up linked and unlinked customers separately. Note that what you use here is a Segment, which is a filtering condition for friends. It is a different concept from a friend's tag, so be careful not to confuse them. If many customers are unlinked, it is a good idea to point them to additional ID linkage methods.

When Things Do Not Work

Common ID linkage issues and how to address them are listed below.