Out-of-stock products mean lost revenue and missed chances to keep shoppers coming back. Adding a “Notify When Back in Stock” or waitlist feature lets customers sign up for alerts and return ready to buy. It also builds goodwill and repeat traffic without extra ad spend.
TL;DR
– Two simple ways to add back-in-stock alerts to WooCommerce:
1) Merchant Pro (paid) — an all-in-one WooCommerce toolkit that includes a Waitlist module plus 40+ conversion features. Easy, visual setup and automated emails.
2) Back in Stock Notifier for WooCommerce (free) — a dedicated waitlist plugin with granular controls and bot protection. Slightly more hands-on to configure.
Before you start: set up SMTP
WordPress’ default PHP mail often fails spam checks. Install an SMTP plugin (for example WP Mail SMTP) so notifications reliably reach customers. SMTP also provides logs to confirm delivery.
Method 1 — Merchant Pro (recommended if you want an all-in-one toolkit)
1. Install and activate Merchant Pro
– Purchase/download Merchant Pro, install the plugin zip via Plugins » Add Plugin, and activate it. Enter your license key in Merchant settings.
2. Open the Waitlist module
– In the dashboard go to Merchant » Modules » Boost Revenue and open Waitlist.
3. Configure the Waitlist
– Form settings: customize title, email label, button text, success and unsubscribe messages. Optionally include backorder products or exclude items you will never restock.
– Email settings: enable automatic emails for new subscribers and stock updates. Edit the confirmation email and the in-stock notification; preview both before saving.
– Shortcode: enable the shortcode option if you want to place the form manually using [merchant_module_wait_list].
4. Enable and test
– Click Enable to go live. Test by marking a product out of stock, visit its page, subscribe, then restock the product to confirm the in-stock email is sent.
Alternative: manual stock update emails
– Merchant lets you send bulk emails to waitlist subscribers via Products » Waitlist Subscribers. Use this for special previews or manual notifications, but avoid repurposing the list for unrelated marketing without consent.
Method 2 — Back in Stock Notifier for WooCommerce (free)
1. Install and activate the plugin
– Search for Back in Stock Notifier under Plugins » Add Plugin, install and activate.
2. Access settings
– Go to Instock Notifier » Settings to configure the plugin.
3. Key setting areas
– Front End Form: choose inline or popup display, adjust field placeholders and button label.
– Visibility Settings: control where the form appears and hide it for discontinued or archived categories to avoid false expectations.
– Message Settings: customize on-screen messages and the content of the notification email.
– Mail: set sender name/email and subject. Use your store name so recipients recognize the message.
– Background Process: choose WooCommerce background process for consistent handling, or the plugin default if needed for compatibility.
– Bot Protection: enable Turnstile (Cloudflare) or Google reCAPTCHA to block spam signups. For reCAPTCHA, install an integration plugin, register your site at Google reCAPTCHA admin, and paste the Site and Secret keys into the plugin settings.
– Auto-Delete Settings: remove old or inactive subscribers automatically to keep the database lean and comply with retention policies.
– Quantity Field: optionally collect how many items a customer wants when subscribing.
– Checkbox Subscribe Form: add a simple consent checkbox on product pages as an alternative to a popup.
– Estimate Stock Arrival: show an ETA message on the subscribe form to set expectations.
– Troubleshoot: experimental debug tools for advanced users if notifications don’t behave as expected.
4. Save and verify
– Save changes, visit an out-of-stock product, click Subscribe Now and confirm the popup/form works. Check Instock Notifier » All Subscribers for a log of subscriptions and statuses.
Bot protection and deliverability
– Use reCAPTCHA or Turnstile to block bots. Use SMTP to improve deliverability. If emails are delayed, verify your SMTP provider and background process settings.
Testing tips
– Mark a product out of stock to see the front-end form.
– Subscribe using a test email, then restock the product and confirm the in-stock email arrives.
– Check plugin logs or WP Mail SMTP logs to troubleshoot failed sends.
Bonus: increase the impact of your waitlists
– Pair restock alerts with a clear CTA and product page optimizations like trust badges, upsells, countdowns, and smart search to convert returning visitors.
– Use segmentation: customers who subscribed are warm leads — consider personalized offers or follow-ups, but respect consent and data privacy.
Common FAQs
Q: How do I send these emails? A: Use a waitlist plugin (Merchant Pro or Back in Stock Notifier) and an SMTP plugin to deliver notifications automatically when stock is updated.
Q: Can I customize the emails? A: Yes. Both plugins let you edit the confirmation and in-stock email content and preview messages.
Q: How do I see who was notified? A: Merchant: Products » Waitlist Subscribers. Back in Stock Notifier: Instock Notifier » All Subscribers.
Q: What if emails aren’t delivered immediately? A: Likely your site is using PHP mail. Set up SMTP and check background process settings.
Next steps
– Implement an SMTP provider, install either Merchant Pro or Back in Stock Notifier, configure the waitlist settings, and test thoroughly. After that, explore upsells, wishlists, flash sales, and other conversion tools to make returning traffic more valuable.
Adding back-in-stock notifications is a low-friction way to recover lost sales and turn interested shoppers into buyers. With a reliable SMTP setup and one of the two plugins above, you can start capturing demand and re-engaging customers the moment stock returns.