How to send back in stock reminder email through Klaviyo

STOQ can send a back-in-stock reminder email through Klaviyo to customers who received the initial restock alert but haven't purchased yet. This follow-up email is sent automatically after a set number of days, giving customers a second nudge while the product is still in stock.

This guide covers how to enable the reminder notification in STOQ, configure the wait period, and set up the corresponding Klaviyo flow so reminder emails are delivered through your Klaviyo account.

How Reminder Emails Work

STOQ's notification sequence for back-in-stock alerts has two steps: the automatic notification and the reminder notification. The reminder is an optional follow-up that targets customers who still haven't purchased after receiving the initial alert.

Here is how the reminder flow works:

A customer signs up for a back-in-stock notification on your product page.
You restock the product in Shopify.
STOQ sends the initial back-in-stock alert (through Klaviyo or STOQ, depending on your email provider settings).
After a set number of days, STOQ checks whether the customer has purchased the product.
If the customer hasn't purchased the product and it is still in stock, STOQ triggers a reminder event in Klaviyo.
Klaviyo receives the event and sends the reminder email using your reminder flow template.

The reminder uses a separate Klaviyo metric from the initial alert:

Metric name	Purpose
Back in stock alert (STOQ)	Initial restock notification (automatic notification)
Back in stock reminder 1 (STOQ)	Follow-up reminder sent after a configurable number of days

Note: If you connected Klaviyo using a Private API key (legacy method), the reminder metric name is "Stoq - Back In Stock Reminder 1" instead.

Prerequisites

Before setting up reminder emails through Klaviyo, make sure:

You have already connected STOQ's Klaviyo app and set up the initial back-in-stock alert flow. See Send automatic back-in-stock alerts with STOQ's Klaviyo app for setup instructions.
The automatic notification (initial alert) is enabled and working.
You are on a paid STOQ plan.

Step 1: Enable the Reminder Notification

The reminder notification is a separate step in STOQ's notification sequence. You need to enable it before it can send events to Klaviyo.

From your Shopify admin, open the **STOQ **app.
Go to Back in stock alerts from the main menu.
Under the Notifications tab, you will see the notification sequence with two steps:

When you restock — the automatic notification (initial alert)
Wait X days — the reminder notification

Click the reminder notification step to select it.
Toggle Send reminder notification to On.

Once enabled, the reminder step shows an On badge in the notification sequence.

Step 2: Set the Wait Period

The wait period controls how many days STOQ waits after the initial alert before sending the reminder. The default is 1 day, but you can adjust it to suit your strategy.

With the reminder notification step selected, find the Days to wait field.
Enter the number of days to wait (minimum 1 day).
Click Save.

For example, if you set the wait period to 3 days:

Day 0: Customer receives the initial back-in-stock alert.
Day 3: If the customer hasn't purchased and the product is still in stock, STOQ sends the reminder event to Klaviyo.

Tip: A wait period of 1–3 days tends to work well. Too short and customers may feel pressured; too long and they may have lost interest or the product may sell out.

Step 3: Set Up the Reminder Flow in Klaviyo

The reminder email needs its own Klaviyo flow, separate from the initial back-in-stock alert flow. If you used automatic setup when connecting Klaviyo, STOQ already created both flows for you. If you used manual setup, you need to create the reminder flow yourself.

Check if the reminder flow already exists

In your Klaviyo account, go to Flows.
Look for a flow triggered by Back in stock reminder 1 (STOQ).
If it exists and is set to Live, your reminder flow is ready — skip to Step 4.

Create a reminder flow manually

If the reminder flow does not exist:

In Klaviyo, go to Flows > Create Flow > Build your own.
Name the flow (e.g., "Back in stock reminder (STOQ)").
Set the flow trigger:

Under Your Metrics, find and select Back in stock reminder 1 (STOQ).

Add an Email action below the trigger.
Design your reminder email template. Since this is a follow-up, consider using messaging like:

"Still interested in [product]?"
"[Product] is still available — don't miss out!"
"Reminder: [product] is back in stock"

Set the flow to Live.

Note: For a complete list of template variables you can use in your reminder email, see Customize your Klaviyo back-in-stock notifications with variables. The reminder flow receives the same product, customer, and shop data as the initial alert.

Step 4: Set Up the Reminder Flow in STOQ

After the Klaviyo flow is created, connect it in STOQ so STOQ knows where to send the reminder events.

In STOQ, go to Back in stock alerts > Notifications tab.
Click the reminder notification step in the notification sequence.
Click Customize email.
In the email customizer, go to the Send emails through section.
Klaviyo should already be selected as your email provider. Under the flow section, you will see the metric name Back in stock reminder 1 (STOQ).
If you used automatic setup, the flow should already be verified with a green checkmark.
If you used manual setup, enter the flow name you created in Klaviyo and click Verify Flow

A green checkmark next to the metric name confirms the flow is connected and ready.

Step 5: Verify the Complete Setup

After enabling the reminder and connecting the Klaviyo flow, verify everything is properly configured.

In STOQ

Go to Back in stock alerts > Notifications tab.
Both notification steps should show an On badge:

When you restock — On
Wait X days — On

If there are Klaviyo configuration issues, a yellow "Klaviyo setup incomplete" banner appears with specific instructions. Click the link to fix the issue for the reminder flow.

In Klaviyo

Go to Flows in your Klaviyo account.
Confirm two separate back-in-stock flows exist:

One triggered by Back in stock alert (STOQ) — for the initial alert
One triggered by Back in stock reminder 1 (STOQ) — for the reminder

Both flows should be in Live status.

Send a test event

In the reminder's email customizer (Send emails through section), click Send test event.
This sends sample data to Klaviyo using the reminder metric, so you can preview the reminder email in Klaviyo's template editor.

Known Limitations

There are a few constraints specific to the back-in-stock reminder email.

Reminder requires the initial alert. The reminder only fires if the customer received the initial back-in-stock alert first. If the initial alert was not sent (e.g., the automatic notification was disabled), the reminder will not be sent either.
Customer must not have purchased. STOQ checks whether the customer has purchased the product before sending the reminder. If they already bought it, the reminder is skipped.
Product must still be in stock. If the product sells out again before the reminder wait period ends, the reminder is not sent.
One reminder level. STOQ currently supports one reminder notification (position 1). Multiple sequential reminders are not available.
Shopify Flow not supported for reminders. If you use Shopify Flow as your email provider, reminder notifications are not available. Reminders can only be sent through STOQ's built-in email or Klaviyo.

Troubleshooting

Here are common issues with back-in-stock reminder emails through Klaviyo.

Symptom	Likely Cause	Fix
Reminder not sending	Reminder toggle is off	Go to Back in stock alerts > Notifications, select the reminder step, and toggle Send reminder notification to On.
"Klaviyo setup incomplete" banner for reminder	Reminder flow not set up in Klaviyo	Click the link in the banner to open the reminder's email customizer. Set up or verify the Klaviyo flow for the reminder metric.
Reminder flow verification fails	Flow name mismatch or flow not live	Ensure the flow name in STOQ matches exactly with the Klaviyo flow name. Set the flow to Live in Klaviyo.
Customers receiving reminder even after purchasing	Timing issue — purchase was not yet synced	This is rare. STOQ checks purchase status before sending, but there may be a brief sync delay.
Want to change how many days to wait	N/A	Select the reminder step in the notification sequence, change the Days to wait value, and click Save.
Reminder email looks the same as initial alert	Using the same template for both	Design a separate template in the reminder Klaviyo flow with different messaging (e.g., "Still interested?" instead of "Back in stock!").

FAQs

Q: Do I need a separate Klaviyo flow for the reminder?

A: Yes. The reminder uses a different metric ("Back in stock reminder 1 (STOQ)") than the initial alert ("Back in stock alert (STOQ)"). Each metric needs its own flow in Klaviyo. If you used automatic setup, STOQ created both flows for you.

Q: What happens if I disable the reminder after some customers already received the initial alert?

A: Customers who already received the initial alert will not get the reminder. STOQ stops sending reminder events as soon as you turn the toggle off.

Q: Can I use a different email provider for the reminder than the initial alert?

**A: **The email provider is set at the account level, not per notification step. If Klaviyo is your email provider, both the initial alert and the reminder are sent through Klaviyo.

Q: Does the reminder count toward my STOQ notification limit?

**A: **Yes. Each reminder event sent to Klaviyo counts as one notification toward your STOQ plan limit, just like the initial alert.

Q: Can I customize the reminder email differently from the initial alert?

**A: **Yes. Since the reminder uses a separate Klaviyo flow, you can design a completely different email template for it. This is recommended — using messaging like "Still interested?" or "Don't miss out" tends to perform better than repeating the initial alert copy.

Q: What if I only want to use Klaviyo for the reminder but STOQ's built-in email for the initial alert?

A: This is not supported. The email provider applies to all back-in-stock notifications. You cannot mix providers between the initial alert and the reminder.

Updated on: 25/04/2026

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