Out-of-stock items cost more than immediate lost orders — they’re missed chances to re-engage shoppers. Adding a “Notify When Back in Stock” option lets customers join a waitlist so you can alert them the moment inventory returns. That converts interest into purchases and builds loyalty.
TL;DR
– Two easy ways to add back-in-stock alerts:
1) Merchant Pro (paid) — an all-in-one WooCommerce toolkit with a Waitlist module plus 40+ conversion features. Best if you want fewer plugins and a visual, integrated setup.
2) Back in Stock Notifier for WooCommerce (free) — powerful, focused waitlist plugin with granular settings and bot protection. Slightly steeper learning curve but no cost.
Before you start
– Use an SMTP plugin so your notification emails reach customers. WordPress default mail can be blocked by spam filters. WP Mail SMTP or another SMTP provider will improve delivery and give you logs so you can confirm sends.
Method 1 — Merchant Pro (recommended if you want an all-in-one solution)
1) Purchase, download, and install Merchant Pro. Activate the license in Merchant » Settings.
2) Open the Waitlist module: Merchant » Modules » Boost Revenue » Waitlist.
3) Configure form settings:
– Enable waitlist on out-of-stock (and optionally backorder) products.
– Customize form title, email label, button text, success/unsubscribe messages.
– Exclude items you never plan to restock (limited editions, seasonal products).
4) Configure email settings:
– Turn on automatic email notifications for stock updates.
– Edit the new-subscriber confirmation and the stock-update email templates. Preview before saving.
5) Shortcode option: enable if you want to place the waitlist form in a custom spot using [merchant_module_wait_list].
6) Enable the module. Out-of-stock product pages will now show the waitlist form.
7) Optional manual send: go to Products » Waitlist Subscribers to bulk-send emails or review who’s been contacted. Useful for special announcements or manual outreach.
Testing tip: Mark a product Out of stock in the product data to see the front-end waitlist form and run through signup and notification flow.
Method 2 — Back in Stock Notifier for WooCommerce (free)
1) Install and activate the plugin: Plugins » Add Plugin, search for Back in Stock Notifier for WooCommerce.
2) Go to Instock Notifier » Settings and walk through these sections:
– Front End Form: choose inline or popup, customize placeholders and button label.
– Visibility Settings: hide the form for discontinued or archived categories so customers don’t sign up for items that won’t return.
– Message Settings: edit on-screen confirmation messages and the email message customers receive when stock returns.
– Mail: set sender name, sender email, and subject line. Use your store name so recipients recognize you.
– Background Process: choose WooCommerce background processes for reliable sending or the plugin default if needed.
– Bot Protection: enable Turnstile (Cloudflare) or Google reCAPTCHA to block automated signups. reCAPTCHA is widely used and free — you’ll need to install an Advanced Google reCAPTCHA plugin and add site/secret keys.
– Auto-Delete: configure rules to remove inactive subscribers (mail sent, unsubscribed, purchased) after X days to keep your database tidy.
– Quantity Field: optionally collect how many items a user wants; make it optional if you prefer a simpler form.
– Checkbox Subscribe Form: enable a consent checkbox variant so users can opt in via a simple product-page checkbox.
– Estimate Stock Arrival (ETA): show an estimated restock date near the submit button to set expectations.
– Troubleshoot Settings: advanced debugging tools for technical issues — use only if you know what you’re doing or under developer guidance.
3) Save changes and visit an out-of-stock product page to test the subscribe flow. Check Instock Notifier » All Subscribers to view logs and statuses.
Bot protection setup (recap)
– For reCAPTCHA v2: register your domain at Google reCAPTCHA admin, copy Site Key and Secret Key, and paste them into your reCAPTCHA plugin settings. Turn on verification in the notifier plugin.
– Turnstile requires Cloudflare and is invisible to users, but needs a Cloudflare account.
Best practices and tips
– Keep messages friendly and on-brand. A clear confirmation and a helpful restock email increase the chance of conversion.
– Don’t reuse waitlist lists for unrelated marketing unless you have explicit consent — subscribers signed up specifically for restock alerts.
– Test the full flow: subscribe, mark product in stock, ensure the notification triggers, and confirm deliverability through SMTP logs.
– Use the quantity field or priority settings to help plan restock quantities based on actual interest.
– Consider using Merchant Pro if you want additional tools (countdown timers, trust badges, upsell modules) in one package.
Quick FAQs
– Can I customize the emails? Yes. Both Merchant Pro and Back in Stock Notifier let you edit email templates and preview them.
– Why are emails delayed or not delivered? Likely because WordPress default mail is used. Set up SMTP (WP Mail SMTP or another provider) to improve reliability.
– Can I see who received notifications? Yes. Merchant Pro shows this under Products » Waitlist Subscribers; Back in Stock Notifier lists subscriptions and status under Instock Notifier » All Subscribers.
– Can I notify customers manually? Yes. Merchant Pro supports bulk sending from the waitlist subscribers screen for targeted messages.
Next steps to increase sales
– Once your waitlist is working, use the returning traffic to upsell or cross-sell related products, run targeted flash sales, or add loyalty incentives.
– Explore additional WooCommerce optimizations: reduce cart abandonment, add wishlists, or improve product search to convert returning visitors into buyers.
Conclusion
Adding back-in-stock notifications is a low-effort, high-impact way to recover lost sales and keep customers connected to your store. Choose Merchant Pro for a polished, all-in-one experience or the free Back in Stock Notifier if you prefer a dedicated, budget-friendly solution. In either case, pair with an SMTP provider, test the flow, and keep messaging customer-focused to maximize conversion.