A back in stock alert is an automatic notification sent to customers when a sold-out product becomes available again. When a product variant runs out of inventory, a back in stock alert system lets interested customers enter their email (or phone number) to get notified the moment you restock. On Shopify, this functionality is added through apps like Storebeep since it is not built into the core platform.
Instead of losing the sale when a product is out of stock, you capture the demand and convert it later.
Why It Matters
Out-of-stock products are an unavoidable part of ecommerce. Popular items sell out. Supply chains have delays. Seasonal products come and go. Without back in stock alerts, a customer who finds your product sold out simply leaves and buys from a competitor.
A customer who signs up for a restock alert has already chosen your product over alternatives. They are telling you they want to buy. All you have to do is restock and notify them.
The conversion rate on back in stock emails is significantly higher than regular marketing emails because the customer has already expressed specific purchase intent. They are not browsing. They are waiting.
How Back in Stock Alerts Work
Step 1: Customer finds a sold-out product. When a product or specific variant is out of stock on your product page, the add-to-cart button becomes inactive.
Step 2: Alert signup appears. A back in stock app replaces or supplements the disabled buy button with a “Notify Me” form. The customer enters their email address.
Step 3: You restock the product. When inventory for that variant goes above zero in your Shopify admin, the app detects the change automatically.
Step 4: Notification fires. The app sends an email (or SMS) to every customer who signed up for that specific product. The email typically includes the product name, image, price, and a direct link back to the product page.
Real Example
A Shopify store selling handmade ceramics frequently sells out of their popular mugs within hours of restocking. Before installing a back in stock alert app, sold-out products generated zero follow-up sales. Customers left and often forgot about the product.
After adding alerts, they collect an average of 340 email signups per sold-out mug. When they restock, the notification email achieves a 42% open rate and 18% click-through rate. Of those who click, 35% complete a purchase. That is 21 sales per restock notification, generated from what used to be $0 in recovered revenue.
How to Get the Most from Back in Stock Alerts
Keep the signup form simple. Email field only. Do not ask for name, phone number, and preferences on a back in stock form. Every extra field reduces signups. Capture the email first, ask for more later.
Send the notification immediately. When you restock, the email should fire within minutes. Hot products sell out again fast. A 24-hour delay means customers see a “back in stock” email for a product that is already sold out again.
Include a direct link to the product. The notification email should link straight to the product page with the restocked variant selected. Do not send them to your homepage or collection page and make them search for it.
Use scarcity honestly. If a product regularly sells out, say so. “Back in stock – limited quantities available” is honest and effective when inventory genuinely is limited.
The back in stock notification is the highest-intent email you can send. Treat it like a VIP message, not a generic marketing blast.
Back in Stock vs. Wishlist vs. Pre-Order
Back in stock alerts notify customers about currently unavailable products when they return to inventory. Wishlists let customers save products they are interested in but not ready to buy yet. Pre-orders let customers buy and pay for products before they are available. Each solves a different problem in the purchase journey.
