Australcode Back In Stock is a back in stock notifier and waitlist for WooCommerce that turns out-of-stock products into recovered sales. It is privacy-first (double opt-in and explicit consent built in), sends through Action Scheduler so big waiting lists never time out, and keeps every core featur
PricingFree downloadThe WordPress.org download is free. Pro versions, add-ons or external services may cost extra.
CompatibilityRequires WordPress 6.5 and PHP 8.1.
SourceWordPress plugins · Nov 5, 2026
01 / Source details
Aboutthistool.
Australcode Back In Stock is a back in stock notifier and waitlist for WooCommerce that turns out-of-stock products into recovered sales. It is privacy-first (double opt-in and explicit consent built in), sends through Action Scheduler so big waiting lists never time out, and keeps every core feature free (Pro adds restock coupons, recovered-revenue tracking, SMS/WhatsApp alerts, Klaviyo & Mailchimp sync and webhooks). When a product is sold out, a “Notify me when available” form appears on the product page. Customers leave their email, and the moment you restock they get an automatic email with a link straight to it.
No more lost sales because a customer couldn’t be bothered to check back.
How it works
01A product runs out of stock.
02A subscribe form appears on the product page (simple, variable, grouped and subscription products).
03Customers enter their email — optionally confirming it first (double opt-in).
04You restock the product.
05Everyone on the waiting list gets an automatic email with a link to buy it.
06Customers can unsubscribe with one click from any email.
Free features
“Notify me when available” form on out-of-stock products — simple, variable, grouped and subscription products (a per-item form on grouped products).
Shortcode and Gutenberg block to place the form anywhere — works with any page builder; add mode="product" for popups and modals (Elementor, Divi).
Automatic restock email with the product’s photo, price and a direct link — a card built to win the sale back, not just notify.
Per-product subscriber list in the admin, with KPIs, a “Top demand” panel, status filters and email search.
Optional double opt-in (email confirmation before subscribing).
Reliable background sending via Action Scheduler — works for products with hundreds of subscribers without timing out.
Cache and CDN proof — the form fetches a fresh security token at submit time, so it keeps working behind full-page edge caches like Cloudflare and Kinsta.
Developer hooks — PHP actions and filters ( acbis_after_subscribe , acbis_email_args ), an acbis:subscribed JavaScript event and an acbis_subscribe() function, to wire signups into your CRM, analytics or email tool, or to add subscribers from another plugin.
Customizable texts — the form’s intro line (or hide it), the button label, the consent wording and the email subject/heading text, all from Settings.
Appearance panel — pick an accent color, an outline or solid button and how round the corners are, so the form matches your theme without writing a line of CSS.
Pro features
Restock coupons — include a unique, single-use discount in each restock email. It is applied automatically at checkout (no copy-pasting), is restricted to the product and the customer’s email, and expires after the window you choose, so the urgency is real.
Recovered-revenue tracking — a dashboard that attributes paid orders back to your restock coupons, so you see exactly how many sales and how much revenue the waiting list brings back.
SMS & WhatsApp alerts — reach customers on their phone too, through your own Twilio account. Opt-in only: the customer adds their number and ticks a separate consent box, and the alert goes out by SMS and/or WhatsApp alongside the email.
Email-marketing sync — every subscriber is automatically added to your Klaviyo list or Mailchimp audience (bring your own API key), so you can build flows and segments around real back-in-stock demand.
Webhooks & demand alerts — fire a signed JSON webhook on every signup and restock (wire it to Zapier, Make, n8n or your own endpoint), and get a Slack or Discord ping the moment a product passes a demand threshold you set. Turn the waiting list into an inventory signal for your team.
Export the subscriber list to CSV (per product, with status and dates).
Get Pro →
Privacy
The plugin sends restock emails through your own site ( wp_mail / your SMTP). The free plugin never sends your subscribers’ data to any third-party service: emails are stored in your own database, and the IP used for anti-abuse rate limiting is stored hashed, never in clear text. Two optional integrations are off by default: the Pro SMS/WhatsApp feature sends the phone number you collect — with the customer’s separate consent — to Twilio to deliver the message, and Freemius handles licensing and updates. Both are described under “External services” below.
External services
Freemius (account, licensing & secure checkout)
Australcode Back In Stock uses Freemius as its billing and licensing platform (Freemius is the Merchant of Record for Pro purchases). Connecting to Freemius is optional : on activation you can click “Skip” and the plugin stays fully functional without ever contacting Freemius.
If you opt in (free or Pro), the plugin sends your admin email , site URL and basic environment data (WordPress, PHP and plugin versions) to the Freemius API (host api.freemius.com , path /v1/ ) to create your account and check for updates.
If you activate a Pro license , the plugin sends your license key and site domain to Freemius to validate the license and enforce the per-plan site limit. The license is re-validated periodically.
Purchases and license management happen on Freemius-hosted pages (hosts freemius.com , users.freemius.com ).
If you open the “Contact Us” screen, the support form is loaded from Freemius and whatever you type there (your name , email address and message ) is sent to Freemius so they can route it to us. Nothing is sent unless you submit the form.
Apart from the support form, no data is sent to Freemius if you skip the opt-in and do not enter a license key.
Terms of Service: https://freemius.com/terms/
Privacy Policy: https://freemius.com/privacy/
Twilio (SMS & WhatsApp delivery — Pro, optional)
The Pro “SMS & WhatsApp alerts” feature is off by default and only works if you enable it and enter your own Twilio credentials. When a subscriber has given phone consent and a product is restocked, the plugin sends the subscriber’s phone number and the message text to the Twilio API (host api.twilio.com , path /2010-04-01/ ) so Twilio delivers the SMS/WhatsApp. Your Twilio Account SID and Auth Token are stored encrypted in your database and used only to authenticate these requests. No data is sent to Twilio unless you enable a channel and configure credentials.
Terms of Service: https://www.twilio.com/legal/tos
The Pro “Email marketing sync” feature is off by default and only works if you enable a provider and enter your own API key. When a customer subscribes to a back-in-stock alert, the plugin sends their email address to the provider you enabled — Klaviyo (host a.klaviyo.com ) or Mailchimp (host <dc>.api.mailchimp.com ) — to add them to the list/audience you choose. Your API key is stored encrypted in your database and used only to authenticate these requests. No data is sent unless you enable a provider and configure it.
The Pro “Webhooks & demand alerts” feature is off by default and only sends data to URLs you configure — it is not tied to any service we operate. When you set a webhook URL, the plugin POSTs a small JSON payload (event type, customer email, product ID and name, timestamp) to that URL on each signup and restock, signed with an HMAC-SHA256 X-Acbis-Signature header so your endpoint can verify it. When you set a Slack or Discord incoming-webhook URL and a demand threshold, it POSTs a short text message to that URL when a product reaches the threshold. The destinations are entirely yours (for example Zapier, Make, n8n, Slack or Discord); review the terms and privacy policy of whichever service you point them at. No data is sent unless you enter a URL.
Hooks for developers
Filters, to change behaviour or markup:
acbis_should_load_assets( $should_load ) — whether the form’s CSS and JS load on the current page. The plugin only loads them where the form can appear (product pages, or a page containing the block or the shortcode). Page builders that render the form inside a modal or popup keep their content outside post_content , so autodetection misses it — force it with add_filter( 'acbis_should_load_assets', '__return_true' ) .
acbis_form_html( $html, $product_id, $is_variable ) — the form markup right before it is emitted, for wrappers, tracking attributes or extra copy. Keep the <form class="acbis-form__form"> and its inputs so the JS and the handler keep working.
acbis_email_args( $args, $type, $context ) — the arguments handed to wp_mail() ( to , subject , message , headers ) for both the confirmation and the restock email. $type is 'confirmation' or 'restock' , and $context carries the product name and URLs, so you can swap the template or route the message through your own mailer.
acbis_restock_coupon( null, $subscription ) — return a coupon array here to attach a discount to the restock email. Returns null by default, which sends the email without one.
Actions, for side effects and extra markup:
acbis_after_form( $product, $html ) — fires right after the form is printed on the product page. Unlike the shortcode and the block, which return their HTML, this is the WooCommerce hook adapter and output is printed here, so an echo lands exactly where you expect: inside the product summary, after the form. It fires even when no form was shown (product in stock, or not resolvable) — '' === $html is that case.
acbis_form_extra_fields( $product_id ) — inside the form, after the email field. Add your own inputs here; they arrive in $_POST at the subscribe handler.
The "Notify me when available" form on an out-of-stock product page.The subscriber list in the admin: who is waiting, how many restock emails already went out, and a "Top demand" panel that ranks your restock priority — all free.Settings — turn on double opt-in and the consent checkbox in one click, no code and no third-party service.The automatic restock email customers receive — one tap from inbox to the product page.Grouped products: a separate "notify me" form for each out-of-stock item in the group — also free.Recovered-revenue dashboard (Pro) — see exactly how many sales and how much revenue the waiting list brings back.SMS & WhatsApp restock alerts (Pro) — reach customers on their phone through your own Twilio account.Appearance panel — pick an accent color, an outline or solid button and how round the corners are. The form matches your theme without a line of CSS. Free.
02 / Source details
Gettingstarted.
01Upload the plugin to /wp-content/plugins/ , or install it from the Plugins screen.
02Activate it. WooCommerce must be installed and active.
03Go to Back in Stock → Settings to review the options (double opt-in, button label, email texts).
04That’s it — the subscribe form shows automatically on any out-of-stock product.
05Want restock coupons, recovered-revenue tracking, SMS/WhatsApp alerts or Klaviyo & Mailchimp sync? See what Pro adds →
03 / Source details
Frequently asked questions.
How does “notify me when back in stock” work?
When a product (or a specific variation) is out of stock, the form appears in place of the add-to-cart area. Customers leave their email — optionally confirming it first (double opt-in) — and when you restock, everyone on that product’s waiting list automatically receives the back-in-stock email with a direct link to buy.
Does it work with variable products?
Yes. For variable products the form appears when the customer selects an out-of-stock variation, and notifies only the people waiting for that specific variation.
Does it support grouped products and WooCommerce Subscriptions?
Yes. On a grouped product, a separate “notify me” form appears for each out-of-stock item in the group, so customers can wait for exactly the ones they want. WooCommerce Subscriptions products are supported too — both simple and variable subscriptions — using the same restock detection as regular products.
Will it send hundreds of emails at once and time out?
No. Sending runs in the background through Action Scheduler (bundled with WooCommerce), in batches, so it scales to large waiting lists.
Do customers need an account?
No. They only leave an email. Confirmation and unsubscribe work through secure tokenized links, no login required.
Does it send my customers’ data anywhere?
By default, no. Restock emails are sent from your site’s own email (wp_mail / your SMTP) and your subscribers’ data stays in your database. Two optional integrations can send data, both off by default: the Pro SMS/WhatsApp feature sends a customer’s phone number (with their consent) to Twilio to deliver the message, and Freemius handles license validation and updates if you opt in. See “External services”.
What happens if my Pro license expires?
Nothing breaks and nothing is deleted. Every free feature keeps working forever — the notify-me form, the automatic restock email, background sending, the subscriber list and one-click unsubscribe. The Pro tools (restock coupons, recovered-revenue tracking, SMS & WhatsApp alerts, Klaviyo/Mailchimp sync and webhooks) turn off while the license is lapsed and turn back on when you renew. Your subscribers, settings and history stay in your own database.
Does the form work with page caching?
Yes. The form is rendered with the product page and submissions go through AJAX, so cached pages keep working. If a cached page is very old (most caches expire within hours), the security token can expire — the customer simply gets a “please refresh and try again” message instead of a silent failure.
Can I restyle the form to match my theme?
You mostly don’t have to. The form inherits your theme: text color, fonts and the hairlines/backgrounds derive from whatever the surrounding page is using, so it follows a light or a dark theme on its own, and the button is an outline that borrows your text color rather than imposing one.
If you do want to adjust it, no code is needed: Back in Stock → Settings → Appearance has an accent color, a button style (outline or solid) and a corner shape. The plugin only writes what you actually change, so anything you had overridden in your own CSS keeps winning. A solid button picks its label color — black or white — from the contrast of your accent, so a light accent does not end up with unreadable white text on top.
To go further than the panel, set CSS variables on .acbis-form, .acbis-grouped — list both so the section chrome of grouped products is themed too, or you get a two-tone widget:
--acbis-accent — focus rings, the bell icon and links. Default #2271b1 .
--acbis-focus — color of the focus ring only. Defaults to --acbis-accent . Set it when your brand color is too light to be visible as a ring: the accent stays on the bell and the links, and the ring gets a color that passes contrast. The Appearance panel sets this for you when you pick an accent that does not reach 3:1.
--acbis-btn-bg , --acbis-btn-fg , --acbis-btn-border — button fill, label and border. Defaults make an outline button that inherits your text color; set all three to go solid and branded.
--acbis-radius , --acbis-field-radius , --acbis-btn-radius — corner radius of the card, the fields and the button ( 12px , 8px , 8px ).
--acbis-border , --acbis-bg , --acbis-field-border — the neutral lines and backgrounds. These derive from your text color automatically, so overriding them is rarely needed.
--acbis-success , --acbis-error — confirmation and error messages.
What makes this plugin a good fit?
It is built for real stores: reliable background sending, double opt-in and explicit consent built in, and a clean admin list to see exactly who is waiting for what. The Pro version adds restock coupons that recover sales automatically, a recovered-revenue dashboard, and one-click CSV export of your subscriber list.
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