Turn the demand you sold out of into sales you can still make.
When a wanted product goes out of stock, the demand does not disappear. It just waits, and most of it walks if you do not reach it. A back-in-stock flow lets shoppers ask to be told when an item returns, then alerts them the moment it does. It is some of the highest-intent, lowest-effort revenue a store can recover, because the customer already told you exactly what they want.
Captured demand, closed on your behalf
A back-in-stock flow is built around one of the strongest signals in ecommerce: a shopper who wanted a product enough to ask you to tell them when it came back. They opt in on the out-of-stock product page, and when inventory returns, Klaviyo sends the alert automatically. Unlike flows that have to create interest, this one just has to not fumble interest that already exists. That is why, for a store that regularly sells out of wanted items, it punches well above the small effort it takes to set up, and why speed and a clean path to buy matter more than any clever copy.
High intent for the right catalog
Not every store needs this flow, and that is worth being honest about. Its value tracks how often you actually run out of products people want. For a brand built on limited drops, popular variants, or fast-moving inventory, it can rival the top-earning flows per recipient, because it fires on the highest intent there is: someone waiting on a specific item. For a store that rarely stocks out, there is simply less demand to recover, and other flows will pay back faster. Judge it by your out-of-stock reality, not by a universal ranking, and where it fits, build it well; the most profitable flows for any store are the high-intent ones you are not yet running.
A back-in-stock flow that works
A fast first alert that makes the sale, then honest, inventory-gated follow-ups. Adapt to your stock levels.
It's back, buy now
The moment the product is restocked
The instant Klaviyo sees the restock, send a clean alert: the exact product they wanted, a clear image and price, and a single button straight to the product or a pre-filled cart. This is the email that makes the money, so keep it fast and frictionless. No discount is needed; the demand is already there.
Honest scarcity
A day later, if they have not bought and stock is limited
For limited inventory, a brief reminder that it is back and going fast earns the fence-sitters, but only if the scarcity is real. Do not manufacture urgency; if there is plenty of stock, skip this email rather than cry wolf and train people to ignore you.
Last call
If it is genuinely selling out again
A final low-stock nudge when the item is truly close to gone. Used honestly and sparingly, this catches the last buyers; used on every restock regardless of stock level, it erodes trust and hurts the flow.
The rules that keep it working
A back-in-stock flow lives on speed and honesty, so the guardrails protect both.
Make the notify-me signup easy to find
The flow can only reach people who opted in. The signup comes from Klaviyo's back-in-stock integration on platforms like Shopify and BigCommerce, or from a developer pushing the subscribe event on a custom storefront; wherever it comes from, it has to be obvious on every out-of-stock product page. The more shoppers who raise their hand while the item is gone, the more demand you can recover when it returns.
Trigger on the restock, and send immediately
Fire the alert on Klaviyo's back-in-stock trigger the moment inventory returns, with no artificial delay. For limited stock the first email wins the sale, so speed matters more here than on almost any other flow.
Only use scarcity when it is real
Low-stock and going-fast lines work because they are true. Applied to a full warehouse they read as manipulation and dull the urgency that makes this flow convert, so gate the follow-up emails on actual inventory levels.
Suppress once they buy, and cap the reminders
Remove anyone who buys the item they were waiting on, filtering on a purchase of that specific variant since they signed up, so a shopper who wanted a large and settled for a medium still hears when the large returns. Keep the sequence short too. Someone who wanted one item does not need a stream of emails; the value is in the fast first alert, not in volume.
How to size the recovered demand
What a back-in-stock flow is worth comes down to how much wanted product you sell out of and how much of that demand you are currently letting walk. A store that frequently runs out of popular items and has no notify-me capture is leaving real revenue on the table every restock; a store that rarely stocks out will get more from a browse abandonment or another core flow first. That is a question about your specific catalog and sell-through, not a generic benchmark. A free Klaviyo audit reads your out-of-stock and demand patterns and estimates what a back-in-stock flow is worth on your store, ranked against every other email you are not sending yet.
Is it safe to connect Klaviyo?
- Read-only. It can read your campaign and flow performance. It cannot send, edit, or delete anything in your account.
- No customer data stored. It works from your metrics, not your subscriber list. Names, emails, and phone numbers are never stored.
- Nothing ships without you. Built emails land as drafts for your review; nothing is pushed to Klaviyo on its own.
- Built by an operator. David Refaeli-Berman ran enterprise email at Chewy, Amazon, Overstock, and Bed Bath & Beyond.
Questions
What is a back-in-stock flow in Klaviyo?
It is an automated email that fires when a sold-out product returns to stock, sent to the people who asked to be notified. Shoppers opt in on the product page while the item is unavailable, and Klaviyo triggers the alert the moment inventory comes back. It is one of the highest-intent emails you can send, because the recipient already told you they want this exact product.
Which stores need a back-in-stock flow?
Any store that regularly sells out of products people want: limited drops, popular sizes and variants, seasonal items, or fast-moving inventory. If you frequently see out-of-stock pages on products with demand, you are losing sales you could recover without new ad spend. Stores that rarely stock out get little from it, which is why its value depends heavily on your catalog.
How fast should a back-in-stock email send?
As close to immediately as possible. Restock intent decays fast, and for limited inventory the people who hear first are the ones who buy before it sells out again. Klaviyo can trigger the alert on the restock event itself, so there is no reason to add a delay. Speed is often the biggest lever on how much a back-in-stock flow earns, especially for limited inventory.
Is a back-in-stock flow worth setting up?
For an inventory-constrained store, it is one of the best returns on a small amount of setup: the demand already exists, the shopper already raised their hand, and you are simply closing the loop. Whether it is a top priority depends on how often you actually run out of wanted products, which a free audit sizes directly against your revenue.
What is the difference between a back-in-stock flow and a browse abandonment flow?
Intent. A browse abandonment flow reaches people who looked at a product but never committed; the intent is early and soft. A back-in-stock flow reaches people who wanted a specific product enough to ask to be told when it returned; the intent is very high. Browse abandonment recovers interest, back-in-stock recovers demand you had already earned.
Find out what your sold-out demand is worth on your store.
A free audit sizes the revenue a back-in-stock flow would recover for your account, then ranks it against the other flows you're missing.
Size my back-in-stock flow free