Klaviyo

Updated 11 November 2026

Overview

This article covers the Klaviyo page. Klaviyo receives a return event and profile properties at every milestone of a return, so your own Klaviyo flows can fire on them. It can also be chosen as the sender of ReturnZen's notification emails instead of ReturnZen hosted email. Klaviyo is optional: with hosted email, the built-in notification templates send on their own and Klaviyo is only needed for your own flows and analytics.

Use the menu on the left to quickly navigate this article.

Before you start

• A Klaviyo account and a private API key with the scopes events:write, profiles:write and accounts:read. The Open Klaviyo button at the top of the page opens Klaviyo's API keys page.

The Klaviyo page

In the admin, go to Tools > Integrations > Klaviyo.

Screenshot

Tools > Integrations > Klaviyo, the status pill, the Private API key field and the Save Changes button

Private API key

1. Paste the key into Private API key.
2. Click Save Changes.

• Status: Not connected before a key is saved. Saved (verifying) while Klaviyo checks it. Connected with your Klaviyo account name once Klaviyo accepts it; the page then shows the account's name. Credentials cannot be read when the saved key can no longer be decrypted. If Klaviyo rejects the key, a line reads Klaviyo rejected this key: followed by Klaviyo's message.

Send sample events

Sends one sample event for every metric ReturnZen sends, with all of its merge tag properties (about 60) filled in, so every variable shows in the personalization picker of Klaviyo's email template editor without waiting for a real return. Dates and times in the samples are written the same way as in real events.

1. Type an address in the email field. Use an inbox you can check: Klaviyo creates a profile for it, which you can delete afterwards.
2. Click Send Samples. The toast reads Sent [n] of [n] sample events to [address]. They show in Klaviyo under Metrics within 1 to 2 minutes.

Note: If none were sent, the toast says why: None of the [n] sample events were sent. Check that Klaviyo is switched on under Integrations, then try again. when the switch on Tools > Integrations is off, or Klaviyo did not accept the [n] sample events: [Klaviyo's reason]. Check your API key under Integrations. when Klaviyo refused them.

Screenshot

The Send sample events card with the email field and the Send Samples button

Install email templates

Copies every notification template to your Klaviyo account as a draft template whose name starts with ReturnZen. Run it again any time to copy edits made in ReturnZen's template editor to Klaviyo.

1. Click Install Templates. The confirmation reads Install templates into Klaviyo? and says an existing template with the same name is updated in place.
2. Confirm. The toast reads Installed [n] new and [n] updated templates. The setup guide is below. and the button now reads Sync Templates.
3. Follow the guide headed Set up these [n] flows in Klaviyo. It lists each flow's Flow name, Trigger metric and Email template. Klaviyo does not let flows be created from outside, so for each flow in the guide: in Klaviyo go to Flows, click Create flow, choose Build your own, set the trigger to the listed metric and pick the listed template on the email step. Each flow takes about 30 seconds.
4. Review each flow in Klaviyo and switch it live when ready. Every flow starts in draft.

Important: Installing again replaces a template of the same name in Klaviyo, including edits made inside Klaviyo. Templates already installed stay as they are until you click Sync Templates.

Screenshot

The Install email templates card after an install, with the Sync Templates button and the flow setup guide table

Disconnect

• Disconnect Klaviyo: at the foot of the page. The confirmation reads This removes your saved Klaviyo API key. No return events reach Klaviyo until you reconnect. Click Disconnect Klaviyo to confirm. Only the key is deleted; templates installed in Klaviyo and your flows stay there.

Sending the notification emails through Klaviyo

In the admin, go to Shopper > Notifications, Email settings.

• Default email provider: the service that sends your notification emails. Options: ReturnZen hosted email, Klaviyo (connected) and None (emails off). With Klaviyo chosen, the page shows the banner Klaviyo flows required.: each enabled notification needs its own flow in your Klaviyo account, triggered by its event (for example ReturnZen Return Created). Without a flow, nothing goes out. See Notifications: who sends the emails and who they come from.

What stops when Klaviyo is off, disconnected or unreadable

Return events and profile updates stop reaching Klaviyo, so any Klaviyo flow built on them stops firing. If Klaviyo is the Default email provider, the notification emails stop going out too until you choose another provider. The Notifications page lists it as Klaviyo (not connected). Where ReturnZen's own email is not available either, the page reads Not sending. No email provider is connected, and no customer notifications are going out. in place of the picker.

A key that is saved but cannot be read shows Credentials cannot be read on the tile and This store's saved Klaviyo key cannot be read. Save the key again on the Klaviyo settings page. on the Klaviyo and Notifications pages; sends refuse until the key is saved again. Reconnecting resumes events without reinstalling anything.

FAQ

Do I need Klaviyo to send return emails? No. ReturnZen hosted email sends every built-in notification with nothing to set up. Connect Klaviyo when you want return events in your own flows, or want Klaviyo to be the sender.

I edited a template in Klaviyo. Will ReturnZen overwrite it? Only when you click Sync Templates (or Install Templates) again. Until then your Klaviyo edits stand.

Please reach out to support@returnzen.app with any additional questions.