What it does
Automatically notifies Shopify customers via email when previously backordered items come back in stock, driving purchase completion and recovering lost sales.
Why I recommend it
Backorders frustrate customers, but manual stock alerts get forgotten. Automated notifications the moment items restock capture pent-up demand while interest is still high, converting backorders to revenue.
Expected benefits
- 30-40% backorder conversion rate
- Recovered lost sales
- Better customer experience
- Reduced support inquiries about stock
How it works
Customer attempts to purchase out-of-stock item -> capture email and product interest -> monitor Shopify inventory levels -> when item restocked -> send email notification with product link and stock urgency (“Limited quantity back in stock”) -> track click-through and purchases -> send reminders if not purchased within 48 hours.
Quick start
Identify frequently backordered products. Manually track customer inquiries about stock. When items restock, manually email interested customers. Measure conversion rates. Then automate inventory monitoring and notification sending.
Level-up version
Waitlist management (customers join waitlist for OOS items). Priority notification for higher-value customers or larger order quantities. Bundle recommendations if original item still OOS. Estimated restock date communication. SMS notifications for high-value items. Pre-order capability before full restock.
Tools you can use
E-commerce: Shopify, WooCommerce, BigCommerce
Email: Klaviyo, Mailchimp, Shopify Email
Inventory: Shopify inventory API
Waitlist: Back In Stock apps, custom forms
Automation: Zapier, Make, Shopify webhooks
Also works with
Platforms: Etsy, Amazon for marketplace alerts
Apps: Restock Rocket, Back in Stock for Shopify apps
SMS: Twilio, Postscript for text notifications
Technical implementation solution
- No-code: Shopify “Back in Stock” app -> customers subscribe to item alerts -> app monitors inventory -> sends emails when restocked.
- API-based: Customer requests notification for OOS item -> store email and product ID in database -> scheduled job monitors Shopify inventory via API -> when quantity >0 -> send personalized restock email -> include urgency messaging -> track purchases -> send reminder if no purchase in 48h -> remove from waitlist after purchase.
Where it gets tricky
Managing inventory fluctuations (restocked then sold out again quickly), timing notifications to avoid overwhelming customers, handling size/variant-specific backorders, and coordinating with supplier restock schedules.
