WooCommerce doesn't have a "back in stock" email. Here's how to fix that.
A shopper finds your product, picks a size, and sees "Out of stock." What happens next? On a default WooCommerce store, nothing. They can't leave their email or ask to be told when it comes back, so they leave, and most of them won't come back on their own.
People are surprised by this all the time. A recent thread on r/woocommerce put it plainly: WooCommerce can send you a backorder email, but it has no "the product you wanted is available again" flow. For something so basic in ecommerce, you need a plugin to get it.
This guide covers what a good back-in-stock setup needs, how to add one for free, and the settings mistakes that quietly stop it from working.
Why back-in-stock alerts are worth setting up
An out-of-stock page isn't a dead end. It tells you that someone wanted to buy. A waitlist turns that interest into something you can use:
- You keep the customer. Instead of going to a competitor, they leave their email and wait for you.
- You get a ready audience the moment you restock. The people on the waitlist have already shown they want that exact product.
- You learn what to reorder. If 40 people are waiting on one variation and 2 on another, your next purchase order is easy to plan.
The last point matters more than most store owners think. A waitlist is demand data you can't get from sales numbers, because sales numbers can't count the purchases that never happened.
What a good back-in-stock plugin should do
- Show the form automatically on out-of-stock pages. You shouldn't have to add a shortcode to every product.
- Support variable products per variation. If someone wants a Medium in blue, they should get an alert when the Medium in blue is back, not when any size comes back.
- Send the email automatically on restock. If you have to remember to send it, it won't get sent.
- Work for guests, not just logged-in customers. Most shoppers don't make accounts.
- Include an unsubscribe link in every email. This is basic respect for subscribers and part of good privacy practice. It shouldn't cost extra.
- Let you see who is waiting for what. You need a subscriber list, not a black box.
- Stay lightweight. A notification form shouldn't slow down your entire store.
How to add back-in-stock notifications with Waitlytics (free)
Waitlytics is a free WooCommerce plugin built for exactly this, and its free version covers every item on the checklist above.
Step 1: Install and activate
In your WordPress dashboard, go to Plugins → Add New, search for "Waitlytics," then install and activate it. WooCommerce has to be installed and active. Waitlytics needs WordPress 6.0+ and PHP 7.4+.
Step 2: Configure the settings
Go to WooCommerce → Waitlytics to set up your notification and email settings. You don't need an API key for any of the back-in-stock features. The free version doesn't connect to any outside AI service.
Step 3: Let the "Notify Me" form do its job
Once it's active, the "Notify Me" form appears on your out-of-stock product pages by itself. Customers enter their email and subscribe. It works for:
- Simple products
- Variable products, per variation, so subscribers get an alert only when their specific variation is restocked
- Backorder products
Guests and logged-in customers can both subscribe.
Step 4: Restock as usual
When a product's stock status changes from "out of stock" to "in stock," Waitlytics emails every active subscriber for that product automatically. You don't have to do anything by hand. Every notification includes a one-click unsubscribe link.
Step 5: Watch your subscriber list and alerts
From the admin you can see every subscriber, their status, and which products they're waiting for. You can also turn on admin alerts, so you get an email when someone new subscribes or when a product's stock drops below a threshold you set. That gives you an early warning before a bestseller runs out.
The setting that breaks back-in-stock forms
This is the most common reason a waitlist form "doesn't show up": your store is hiding out-of-stock products.
In WooCommerce → Settings → Products → Inventory, check the option "Hide out of stock items from the catalog." If it's turned on, shoppers can't reach sold-out products, so they never see the form. If you want to collect waitlist signups, leave out-of-stock products visible.
A few more tips:
- Test a variable product on its own. Choose an out-of-stock variation on the front end, subscribe with a test email, restock only that variation, and confirm the email arrives.
- Check your email deliverability. Restock emails go out through your site's mail setup, so if your store's WooCommerce emails tend to land in spam, fix that with a proper SMTP setup first.
- Write a clear out-of-stock message. "Out of stock, get notified when it's back" converts better than a plain grey label.
Is it GDPR-friendly?
The free version of Waitlytics collects only an email address, and only when the shopper types it in and clicks subscribe. No data is shared with third parties, and every notification email has an unsubscribe link. If you need double opt-in confirmation, that's in Waitlytics Pro.
When to consider Waitlytics Pro
The free version handles the whole notify-and-email loop. Pro ($79/year) is for stores that want to use the waitlist to plan inventory and run marketing:
- AI demand forecasting and smart reorder suggestions. It predicts when products will run out and recommends how much to reorder, using your own OpenAI, Claude, or Gemini API key, with no credits or SaaS fees. Only anonymized sales data is sent, and only when you run a forecast.
- Stockout cost calculator, to see how much revenue you're losing to out-of-stock products.
- Analytics dashboard for subscriber trends, most-wanted products, and conversion rates.
- SMS and WhatsApp alerts via Twilio, plus Mailchimp and Klaviyo sync.
- Custom email templates, a popup form, double opt-in, reCAPTCHA, CSV export, and a My Account page where customers manage their alerts.
- An AI weekly report on inventory health.
The bottom line
WooCommerce doesn't notify customers when a product comes back in stock, so every sold-out page loses sales without you noticing. Adding a back-in-stock form takes about five minutes. Make sure out-of-stock products stay visible, test one variable product from start to finish, and let the waitlist bring those shoppers back.
