RIACO Back In Stock for WooCommerce turns out-of-stock products into a waitlist instead of a dead end. When a product is out of stock, shoppers can leave their email address; when it’s back, every subscriber is notified automatically.

Most “notify me” plugins email subscribers with a plain foreach loop at request time, which risks failing or timing out partway through on a large list. This plugin instead queues each notification as its own background job (via WooCommerce’s bundled Action Scheduler), so one slow send or one failure never blocks the rest of the list, and there’s no single-request time limit to run into.

Features

Frontend signup form — appears automatically on out-of-stock simple and variable products.
[riaco_bis_form] shortcode — for themes that override the single-product template and don’t show the automatic form, or to place the signup form anywhere else (a page, a widget).
Works for guests and members — logged-in customers get their email pre-filled.
No duplicate signups — an email can only be waitlisted once per product, enforced at the database level.
Per-product control — exclude any individual product from the waitlist from its edit screen.
Background email delivery — restock notifications are queued and sent asynchronously, one per subscriber, so large waitlists can’t time out a request.
Customizable emails — subject and message are editable from WooCommerce › Settings › Emails, with placeholders for product name, product URL, and unsubscribe link.
Honeypot spam protection — a hidden field silently rejects bot submissions.
Optional privacy policy consent checkbox — require shoppers to accept your privacy policy before joining a waitlist, toggle it on from Settings.
One-click unsubscribe — every notification includes an unsubscribe link.
GDPR ready — integrates with WordPress’s built-in personal data exporter/eraser tools, and adds suggested privacy-policy content.
CSV export — export the full waitlist (or a filtered view) from the admin screen.
HPOS compatible — fully compatible with WooCommerce High-Performance Order Storage.
Translation ready — all strings are internationalised with a .pot file included.

Compatibility

WooCommerce is in the process of building a native “Customer Stock Notifications” feature (currently unreleased/alpha-gated). This plugin automatically steps aside if that native feature is ever turned on for your store, so the two won’t stack duplicate signup forms.

Minimum Requirements

WordPress 6.4 or greater
WooCommerce 8.0 or greater
PHP 7.4 or greater