Klaviyo back in stock emails: how to set them up so the restock actually sells

What is a Klaviyo back in stock email?

There are really two different emails hiding under one name, and you want both.

The first is the back in stock flow. A shopper lands on a sold-out product, clicks "notify me when available," and leaves their email. When the item comes back, Klaviyo emails them automatically. These people raised their hand for one specific product.

The second is the restock campaign. That's a regular send to your list, or a big chunk of it, saying the thing is back. Most of the people getting it never clicked a notify button. They just know the product, bought it before, or have been waiting quietly.

The flow is small and precise. The campaign is big and broad.

Why does the restock email make so much money?

Because demand has been stacking up while you were out. Every person who would've bought during the stockout is still out there, and now you're telling all of them at once.

Here's what that looked like at the snack brand doing about $650K a month:

• "We're back baby!" went to 30,498 people and made $48,771. That's about $1.60 per person, and it's the brand's best campaign ever.
• Across the account, back-in-stock emails earn about $0.26 per person, against a brand average of about $0.15. That's roughly 1.7x.
• Six different restock emails each made more than $16,000.

That last one matters most. It wasn't a one-time fluke. Restock after restock, the money showed up.

Look at the subject line, too. "We're back baby!" is news. When I pooled subject line data from 7 brands and 2,821 campaigns, news beat brand voice, and vague questions were the worst pattern. A restock is real news. Say it plainly.

How to set up the Klaviyo back in stock flow

Klaviyo has a built-in back in stock feature for Shopify. Here's how it works, based on Klaviyo's help page on building a back in stock flow, and how I'd set it up.

1. Add the "notify me" button. On Shopify, you build the back in stock form in Klaviyo's form builder. It shows up on sold-out products and captures the email.
2. Use the right trigger. The flow triggers on the "Subscribed to Back in Stock" metric. Klaviyo says custom metrics can't trigger this flow, and you shouldn't add trigger or profile filters to it.
3. Let the back in stock delay do the waiting. People who join the flow sit at that delay until their product is restocked. You don't need extra time delays in front of the alert.
4. Set a minimum inventory. You choose how many units have to be back before anyone gets notified. Set it high enough that you won't sell out again in 20 minutes and annoy everyone who rushed over.
5. Decide on batching. By default, Klaviyo notifies everyone at once. You can switch to batches, where it notifies a set number of people per restocked unit and waits between batches. If your restock is small and the waitlist is big, batching is the safer call.
6. Turn Smart Sending off on the alert. Klaviyo recommends this so everyone who asked actually gets the email.
7. Keep it short. Klaviyo suggests 1 to 3 messages. I'd send the alert, then one follow-up a day or two later to the people who didn't buy.

Two notes from my side. Batching settings are account-wide, so they apply to every back in stock flow you run. And like every flow I build, I'd split it for customers and non-customers. Someone reordering their usual flavor doesn't need the same pitch as someone who's never bought.

How to run the restock campaign

The flow only catches the people who clicked a button. The campaign is how you reach everyone else who's been waiting.

Here's how I'd run it:

• Send it fast. As soon as you have enough stock to cover the demand, send. Don't sit on a restock for a week waiting for a "good day."
• Lead with the news. "It's back" beats anything clever. Keep the subject line under 50 characters as a starting point.
• Pick your audience on purpose. Past buyers of that product first, then engaged subscribers. If stock is tight, send to the warmest people first and widen it later.
• One CTA destination. Send people straight to the product page, not the homepage.
• Plan a follow-up. A second send to non-buyers a few days later is normal. If you sell out again, send a quick "gone again" note and point them to the notify button.

Should you run a waitlist?

If you know a restock or a new flavor is coming, yes. A waitlist is just a back in stock list you build on purpose, before the item exists or before the restock date.

Here's how I'd do it:

• Put a signup form on the product page or a dedicated landing page.
• Tag anyone who joins with a profile property or add them to a list, so you can find them later.
• Email them first, before the general restock campaign. Early access is a real reason to join.
• Then run the normal restock campaign for everyone else.

A waitlist also gives you a rough read on demand before your next production order.

What happens when a restock email gets clicks and no sales?

Something broke. That's the rule.

A fitness gear brand sent a restock email that got a 0.40% click rate, double its other sends. It made $0. People wanted the product. They clicked. Then nothing.

When I see clicks with no sales, these are the usual suspects:

• The product sold out again before people got to it, or the variant they wanted wasn't actually back.
• A bad link. Wrong product, a dead URL, or a link to a collection page where the item isn't listed.
• The landing page. The add-to-cart button doesn't work, the page shows "sold out" from a cached version, or the discount code in the email doesn't apply.
• Broken tracking. Across my portfolio, about 20 sends showed opens and revenue but zero clicks. That doesn't happen in real life. It means tracking was broken, so the reporting couldn't be trusted.

So before any restock goes out, click every link, on your phone and on desktop. Add the product to the cart and get to checkout. On your biggest send of the month, that's five minutes well spent.

If your restock emails keep underperforming, it's worth running through a full Klaviyo audit checklist to find what else is quietly broken.

Where these numbers come from

The restock figures are from single brands I work with, described by category and size. The subject line pattern comes from 7 brands and 2,821 campaigns. Treat all of it as directional, not a benchmark for your store.

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WRITTEN BY Jack White

Founder of Bardown Digital, a Chicago-based Klaviyo email and retention agency for Shopify brands. He's worked with brands doing $500K to $100M a year, with $100M+ in email-attributed revenue across them.

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