Create a Back in Stock Flow



Klaviyo currently only supports Back in Stock flows for Shopify stores.


The Back in Stock feature for Shopify stores has two key components:

  1. Back in Stock Flow: When someone subscribes to a restock alert, a "Subscribed to Back in Stock" event will be tracked on their Klaviyo profile. This is the event you will use to trigger your Back in Stock Flow. Shoppers will enter the flow when they subscribe to a restock alert and wait at a "Back in Stock Delay" until their item of interest is restocked.
  2. Website Button: Once your flow is ready and waiting, add a snippet to your Shopify theme that will automatically show an "email me when available" button when items become sold out. When shoppers click this button, they'll fill out a form and go right into your flow.

This guide will focus on building a Back in Stock Flow, which you will want to set up before you install the website button.

Setup a Back in Stock Flow

Klaviyo has two powerful pre-built Back in Stock flows available in the Flow Library

Navigate to the Flow Library by clicking Browse Ideas in the upper righthand corner of the main Flows page. You can find all loyalty and sales-oriented flows we offer for Shopify stores by filtering your view by the following goals: "Convert Sales", "Build Loyalty". You can also easily find these available Back in Stock flows by searching for "Back in Stock".

There are two options available out-of-the-box:

  • Standard. A standard flow that will automatically alert customers when items they're interested in get restocked.
  • VIP vs. Non-VIP. Give VIPs advanced notice when items they're interested in get restocked! This is a more sophisticated version of the standard flow.

After populating any flow in your account from the Library, we recommend reviewing all email content and updating the templates to match your brand.

If you'd like to build a Back in Stock flow from scratch, you can do this too!

mceclip0__1_.pngClick Create Flow and name your Back in Stock flow.

1. Setup Flow Trigger: Once in the visual flow builder, choose the trigger option Takes an ActionIn the dropdown menu that follows, choose the metric, "Subscribed to Back in Stock". Do not add any Trigger Filters or Flow Filters, and click Done.

2. Add Back in Stock Delay: The next component you will want to drag in -- directly after the Trigger -- is the Back in Stock Delay. Recipients that enter your flow will wait at the Back in Stock Delay until their item of interest is restocked. After this occurs, they will move on to the next step in your flow (which will typically be an email notification). To configure your restock email notification, drag in an Email component and place it directly below the Back in Stock Delay.

3. Configure your Back in Stock Email: Typically, you will only need a single email in this flow, as a Back in Stock flow serves a transactional purpose. Below, you'll learn how to setup this template to dynamically pull in the right product data. Make sure to turn Smart Sending OFF for this email to ensure everyone gets the alert.

You do not need to add any Time Delays in this series, as the Back in Stock Delay will ensure each person that enters your flow waits until the item they subscribed to goes back in stock before moving forward.

Back In Stock Flow Settings

There are two key settings you can adjust regarding your Back In Stock flow:

  • Minimum inventory rules
  • Customer notification rules

These can be configured in your Account's Email Settings.

Minimum Inventory Rules

Minimum inventory rules refer to how many items need to be restocked before you notify those who subscribed.

Depending on how you handle restocking when inventory runs out, you may only receive a few products in for a given SKU or variant at a time. If this is the case, you may prefer to have a threshold at which you consider the volume significant enough to let people know the item is back in stock. 

Under Back in Stock Settings in your account's Email Settings, you will see "Minimum Inventory Rules." This is where you can decide the threshold for notifying customers when an item is restocked.

Customer Notification Rules

Customer notification rules have two sub-settings that work together to customize how many and how frequently Klaviyo sends Back In Stock emails. These settings allow you to send restock notifications all at once, or in batches. The two components that you can configure are: 

  • Customers to Notify
    This determines how many customers are notified of each item that is restocked. If you have a high-demand item, you might get hundreds of subscriptions after it goes out of stock. If one item is restocked, you don't want to email all of those people for that single item.

  • Wait Time Between Notifications
    This determines how long we will wait between batches of emails if you choose to specify the number of emails that are sent out per item that is restocked. If a single item is restocked and "customers to notify" is set to 5, for example, we will email the 5 oldest subscribers. We will then wait for this amount of time before emailing the next 5 oldest subscribers. We will continue sending batches until the existing inventory drops below your account's minimum inventory threshold.

    If additional items are restocked during the waiting period, we will not send additional emails until the end of the waiting period. At the end of the waiting period, we will determine how many items are in stock for this item and notify the correct number of subscribers.


Configure Back in Stock Alert Email Content

All pre-built Back in Stock flows you'll find in the Flow Library come configured with default email content. If you've built your own flow, to help get you started, you will find a pre-built Back in Stock email template in the Template Library. Simply search "Shopify Back in Stock" in the themed section of the Template Library when configuring your stock alert email. 

To configure your email content, you will need to use a specific set of dynamic event variables. Given it may be days, weeks, or even months before an item is restocked, we realize that details about the item (e.g. images or price) may change. For this reason, we have a special set of dynamic event variables for this email that will lookup the restocked product in your catalog at send time and populate the most up-to-date details available.

Product Detail Dynamic Event Variable
Product Title {% catalog event.VariantId integration='shopify' %} {{ catalog_item.title }} {% endcatalog %}
Product URL {% catalog event.VariantId integration='shopify' %}{{ catalog_item.url }}{% endcatalog %} 
Product Price {% catalog event.VariantId integration='shopify' %}{{ catalog_item.price }}{% endcatalog %}
Variant Image {% catalog event.VariantId integration='shopify' %} {{ catalog_item.variant.featured_image.full.src|default:catalog_item.featured_image.full.src }} {% endcatalog %}
Variant Title {% catalog event.VariantId integration="shopify" %} {{ catalog_item.variant.title }} {% endcatalog %}
Variant URL {% catalog event.VariantId integration='shopify' %}{{ catalog_item.url }}?variant={{ }}{% endcatalog %}

Here's what a template will look like inside the Template Builder with dynamic event variables, with a comparison of what this same template will look like when previewed with real event data:


Make sure to turn Smart Sending OFF for this email to ensure it gets prioritized and sent even if there are other emails also scheduled to send at the same time.

How It Works

When a customer subscribes to an out of stock product on your site, you'll see an event tracked on their profile: Subscribed to Back in Stock

Those that subscribe to a Back in Stock alert will automatically enter your flow triggered off this Subscribed to Back in Stock event. You will see them added to the "Waiting" list of recipients at the Back In Stock Delay. To explore who is waiting at this step, click View Activity in the configuration sidebar for this delay.


When a product comes back into stock, you'll see those waiting on this item move into the "Moved to Next Step" category.

To view recipient activity around your stock alert email, click on the email itself. Here, in the sidebar, you will see a summary of activity over the last 30 days. Click View all Analytics to explore activity over a longer, or custom, timeframe.

Back in Stock Reports

Check the Back in Stock Reports page to see activity on your Back in Stock flow. Navigate to this page by clicking on a Back in Stock Delay component, and then clicking the View Back in Stock Product Request Report link in the left sidebar.

In this report, you can tell information about the products that are queued for Back in Stock notifications, as well as the number of Back in Stock messages that have been queued, sent, and canceled.


You can also subscribe to receive email notifications for this report by clicking the Subscribe button.

The Scheduled Reports tab allows you to adjust which reports you're subscribed to and the settings for each report.

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