The back in stock email Klaviyo strategy for ecommerce is the highest-performing email type in any DTC brand’s arsenal. There is one email type that reliably achieves 60 percent open rates or higher, consistently, across categories and industries. It is not the welcome email. It is not the abandoned cart email. It is the back-in-stock notification — and most brands either do not have it set up or are executing it incorrectly.
The psychology of pre-commitment
A back-in-stock notification subscriber is the highest-intent subscriber segment that exists. They found the product. They wanted it. They went out of their way to be notified rather than just checking back later. That level of intent does not degrade quickly — but it does degrade. Which brings us to the most important thing about back-in-stock emails: send them immediately. Every hour of delay between a product coming back in stock and the notification email going out reduces conversion rate. The subscriber made their decision when they signed up. What you are doing with the email is opening the door. Do not make them wait. They completed an active opt-in action for a specific product. That is the strongest buying signal in ecommerce.
The back-in-stock email that converts
This email should be short. The subscriber does not need convincing — they are already sold. ‘Good news: [Product Name] is back in stock. We do not know how long it will last. [Link to buy].’ Maybe one line about what makes the product worth returning for, in case they signed up a while ago and could use a quick reminder. A direct link to the product page. Nothing else.
What undermines back-in-stock emails: making them too long, adding other products or promotions, using urgency language that feels manufactured, or delaying the send until the next batch email. Anything that adds friction between the notification and the checkout page reduces conversion. The intent of the recipient is at its peak when they receive the notification. Treat it accordingly.
How to set it up in Klaviyo
Klaviyo integrates with most back-in-stock apps on Shopify. The subscriber opts in through an app — Klaviyo’s native back-in-stock feature or third-party apps. When the product variant returns to inventory, the app triggers a Klaviyo flow for all subscribers waiting for that specific variant. Configure the flow to send immediately with no delays. This flow requires zero ongoing management once set up and delivers some of the highest return per email of any automation in your program.
The Klaviyo Flow Optimization Workbook covers the full build for back-in-stock and every other major Klaviyo flow — $17 at signifystudio.com/library.
Need more tools and frameworks? Browse everything at signifystudio.com/library.
Want the rest of the system, not just this fix?
Run a free FlowScore audit to see what else your Klaviyo account is missing, or go deeper with the Email Psychology Mini Course ($47) or Email Mastery for Health & Wellness Brands ($297).
