RMS Preorder | Back in Stock — Store Owner Guide

Recover lost sales automatically. RMS Preorder | Back in Stock lets your customers sign up for email alerts when sold-out products are restocked — and accept preorder interest before products are available — so you never miss a conversion again.

Table of Contents

• 1. Getting Started
  • 1.1 Installing the App
  • 1.2 Enabling the Storefront Widget
  • 1.3 How It Works — Overview
• 2. Dashboard
  • 2.1 Quick Stats
  • 2.2 Current Plan and Email Usage
  • 2.3 Recent Signups
• 3. Back in Stock Notifications
  • 3.1 Viewing Subscriber Notifications
  • 3.2 Manual Notifications
  • 3.3 Automatic Notifications
  • 3.4 Unsubscribe Handling
• 4. Preorder Signups
  • 4.1 Enabling Preorders
  • 4.2 How Preorders Work
  • 4.3 Preorder Cart Mode
  • 4.4 Preorder Analytics
• 5. Settings
  • 5.1 Button Customization
    • 5.1.1 Button Placement
    • 5.1.2 Button Label
    • 5.1.3 Button Styling
    • 5.1.4 Button Colors
    • 5.1.5 Low Stock Widget
    • 5.1.6 Preorder Settings
  • 5.2 Popup Customization
    • 5.2.1 Back in Stock Form Popup
    • 5.2.2 Back in Stock Success Popup
    • 5.2.3 Preorder Popup
    • 5.2.4 Salutation Selector
  • 5.3 Email Customization
    • 5.3.1 Back in Stock Email
    • 5.3.2 Preorder Email
    • 5.3.3 Template Variables
    • 5.3.4 Custom Email Sender Domain
    • 5.3.5 Merchant Low-Stock Alerts
  • 5.4 Language and Localization
  • 5.5 Preview Mode
• 6. Analytics
  • 6.1 Dashboard Stats
  • 6.2 Daily Trends
  • 6.3 Top Products
  • 6.4 Product-Level Analytics
  • 6.5 Preorder Analytics
  • 6.6 Exporting Subscriber Data
• 7. Subscription Plans and Billing
  • 7.1 Plan Comparison
  • 7.2 Free Plan
  • 7.3 Starter Plan
  • 7.4 Growth Plan
  • 7.5 Enterprise Plan
  • 7.6 Annual Billing Discount
  • 7.7 Free Trial
  • 7.8 Upgrading, Downgrading, and Cancelling
• 8. Mobile Experience
• 9. Privacy, GDPR, and Data Handling
• 10. Frequently Asked Questions
• 11. Troubleshooting
• 12. Support

1. Getting Started

1.1 Installing the App

1. Visit the RMS Preorder | Back in Stock listing on the Shopify App Store.
2. Click Add app and authorize the requested permissions.
3. The app installs automatically and you are redirected to the Dashboard inside your Shopify admin.

The app requires the following permissions:

1.2 Enabling the Storefront Widget

After installation the notification button does not appear on your store automatically. You need to enable the app embed in your theme:

1. From your Shopify admin, go to Online Store > Themes.
2. Click Customize on your active theme.
3. In the theme editor, open the App embeds panel (the puzzle-piece icon on the left sidebar).
4. Find Back in Stock Button in the list and toggle it on.
5. Click Save.

The notification button now appears automatically on every product page where a variant is out of stock. No code editing is required.

For detailed instructions and tips, visit our full documentation.

1.3 How It Works — Overview

RMS Preorder | Back in Stock operates in four simple steps:

1. Button appears — When a product variant is out of stock, a customizable "Notify Me" button appears on the product page. If preorders are enabled, a "Preorder" button appears instead.
2. Customer signs up — The customer clicks the button, enters their details in the popup, and submits.
3. Restock detected — When you restock the product (inventory quantity goes from 0 to 1+), Shopify sends an inventory webhook to the app.
4. Email sent automatically — The app immediately sends a back-in-stock notification email to every customer who signed up for that variant, complete with the product image, price, and a direct link to purchase.

No manual intervention is required after the initial setup. The entire flow from restock to email notification is fully automated.

2. Dashboard

The Dashboard is your home screen. It provides an at-a-glance overview of your notification activity.

2.1 Quick Stats

Four key metrics are displayed at the top of the Dashboard:

2.2 Current Plan and Email Usage

Below the quick stats, you will see your current subscription plan and a visual progress bar showing how many of your monthly email notifications have been used. If you are approaching your limit, an upgrade prompt will appear with a direct link to the billing page.

2.3 Recent Signups

A table of recent customer signups is displayed, showing:

• Customer name and email
• Product and variant they signed up for
• Current status (pending, sent, or unsubscribed)
• Signup date
• Available actions (e.g., manually send a notification)

Click Refresh to update the list with the latest signups.

3. Back in Stock Notifications

3.1 Viewing Subscriber Notifications

Navigate to the BIS Signups tab to see a full list of all customer signup requests. Each entry includes:

• Customer details — Name, email, and salutation (if enabled)
• Product info — Product title, variant title, and a link to the product page
• Status — Pending (waiting for restock), Sent (email delivered), or Unsubscribed (customer opted out)
• Timestamps — When the signup was created, when the notification was sent, and when (if applicable) the customer unsubscribed

3.2 Manual Notifications

You can manually send a notification to any customer with a "pending" status by clicking the Notify button next to their entry. This is useful when:

• You know a product is back in stock but the automatic webhook has not triggered yet.
• You want to send a notification for a product that was briefly out of stock.
• You are testing your email template.

Each manual notification counts toward your monthly email quota.

3.3 Automatic Notifications

Automatic notifications are the core feature of the app. When Shopify detects that a product's inventory level has increased from zero to one or more units, the app automatically:

1. Identifies all pending signups for that specific product variant.
2. Sends a personalized back-in-stock email to each customer.
3. Marks each notification as "sent" with a timestamp.
4. Tracks the event in your analytics.

The entire process runs in the background with no action required from you.

Important: Automatic notifications respect your plan's monthly email quota. If you reach your limit mid-month, remaining notifications are held until the next billing cycle or until you upgrade your plan.

3.4 Unsubscribe Handling

Every notification email includes an unsubscribe link at the bottom. When a customer clicks it:

• Their notification status is changed to "unsubscribed."
• They see a confirmation page in their browser.
• They will no longer receive notifications for that specific product variant.

Unsubscribes are tracked in your analytics and visible in the BIS Signups list.

4. Preorder Signups

4.1 Enabling Preorders

To enable preorder functionality:

1. Go to Settings > Button.
2. In the Preorder card, toggle Enable Preorder Mode on.
3. Set the Preorder Tag — products with this tag will show a preorder button instead of the back-in-stock button.
4. Customize the preorder button text (e.g., "Pre-order Now").
5. Click Save Settings.

4.2 How Preorders Work

When preorders are enabled:

1. Products tagged with your preorder tag display a "Pre-order" button on their product page.
2. Customers click the button and fill in the preorder signup form.
3. Their signup is recorded with a status of signed_up.
4. When the customer places an order containing the preorder product, the signup status automatically updates to ordered (via the order creation webhook).
5. When the order is paid, the status updates to paid.

4.3 Preorder Cart Mode

You can choose how the preorder button behaves:

• Signup only — The button opens a popup where the customer registers their interest. No product is added to the cart.
• Add to cart — The button adds the product directly to the customer's cart, allowing them to complete the purchase immediately. The app can optionally set the product's inventory policy to allow overselling.

Configure cart mode in Settings > Button > Preorder.

4.4 Preorder Analytics

Preorder signups are tracked separately in the Analytics tab. You can view:

• Total preorder signups
• Signups that converted to orders
• Signups that converted to paid orders
• Conversion rates

Each plan includes a monthly preorder signup limit (see Plan Comparison).

5. Settings

The Settings page is organized into four tabs: Button, Popup, Email, and Subscription & Billing. A live preview panel on the right shows your changes in real time before saving.

The Settings page includes a feature mode switcher at the top — toggle between Back in Stock and Preorder to configure each mode's settings independently.

5.1 Button Customization

5.1.1 Button Placement

Choose where the notification button appears on your product page:

For the left/right edge placements, an additional Position from top slider lets you control the vertical position (0–500px from the top of the viewport).

5.1.2 Button Label

Customize the text displayed on the button. The default is "Email me when available." You can change this to anything that suits your brand — for example, "Notify Me When Back in Stock" or "Get Restock Alert."

The button label supports multiple languages. When you switch the User Interface Language selector, the label field updates to show the translation for that language. See Language and Localization.

5.1.3 Button Styling

Fine-tune the button's appearance with these controls:

The button's font family, font size, and font weight are automatically inherited from your Shopify theme, ensuring the button looks consistent with the rest of your store.

5.1.4 Button Colors

Customize the button's appearance with four color settings:

Note: The Free plan only supports the default black and white color scheme. Custom colors are available on the Starter plan and above.

5.1.5 Low Stock Widget

The low stock widget adds an urgency badge (for example, "Only 3 left!") to products that are nearly out of inventory. It is available on all plans, including Free.

In Settings > Button, in the Low Stock Widget card, you will see:

• Show Low Stock Indicator — A toggle that turns the widget on or off for your storefront.
• Low Stock Threshold — A slider that controls when the badge appears (e.g., at or below 5 units). If inventory for a product drops to this number or lower, the "Only X left!" badge is shown.
• Low Stock Message — A customizable text field where you can define the exact badge message. Use {{count}} as a placeholder for the current inventory number (for example, Only {{count}} left!).
• Badge Background Colour — A colour picker (and hex input) for the low stock badge background. The default is a soft amber (#FFF3CD).
• Badge Font Colour — A colour picker for the badge text colour.

When enabled, the widget appears automatically on supported product pages; no theme code changes are required.

5.1.6 Preorder Settings

In Settings > Button, the Preorder card contains:

• Enable Preorder Mode — Toggle to activate preorder functionality.
• Preorder Tag — The product tag that triggers the preorder button (e.g., preorder).
• Cart Mode — Choose between signup-only or add-to-cart behaviour.
• Auto Inventory Policy — When enabled, the app automatically sets the inventory policy to allow overselling for preorder products.
• Button Text — Customize the preorder button label.

5.2 Popup Customization

When a customer clicks the notification button, a popup (modal) appears where they enter their details. The popup has separate settings for Back in Stock and Preorder modes.

5.2.1 Back in Stock Form Popup

Customize the signup form that customers see:

The popup also displays the product name and variant title below the heading, so the customer knows exactly which item they are signing up for.

5.2.2 Back in Stock Success Popup

After a successful signup, a confirmation screen replaces the form:

The success popup automatically closes after 5 seconds.

5.2.3 Preorder Popup

The preorder popup has its own set of customizable fields:

5.2.4 Salutation Selector

Optionally display a salutation dropdown (Mr., Mrs., Ms., Dr., Prof.) in the signup form. This is hidden by default. To enable it:

1. Go to Settings > Popup.
2. Toggle on Display Salutation Selector.
3. Customize the list of salutations (comma-separated) if needed.
4. Click Save Settings.

5.3 Email Customization

5.3.1 Back in Stock Email

Customize the notification email that is sent to customers when a product comes back in stock:

The email is automatically styled with your button colors and includes:

• Product image (if available)
• Product title and variant name
• Price and currency
• A "Shop Now" button linking directly to the product page
• An unsubscribe link

5.3.2 Preorder Email

The preorder email has separate subject and template fields that can be customized independently from the back-in-stock email:

5.3.3 Template Variables

Use these placeholders in your email subject and body text. They are automatically replaced with real values when the email is sent:

Example subject line: {{product_name}} is back in stock! Example body: Good news! {{product_name}} - {{variant_title}} is now available.

5.3.4 Custom Email Sender Domain

By default, all notification emails are sent from no-reply@reedmace.net. On the Growth and Enterprise plans, you can customize the sender identity so emails appear to come from your own brand:

How verification works:

1. Enter your sender name, email, and domain in the settings.
2. Click Save Settings.
3. A verification request is submitted automatically.
4. You will receive verification instructions at the sender email address you provided.
5. Complete the verification steps (typically adding DNS records to your domain).
6. Once verified, a green "Verified" badge appears next to the Domain & Email Sender heading.

While verification is being processed, emails continue to be sent from the default address (no-reply@reedmace.net).

5.3.5 Merchant Low-Stock Alerts

In addition to notifying customers, the app can also notify you when products are running low.

Under Settings > Email, you will find the Merchant Alerts card:

• Enable Low Stock Alerts for Me — A toggle that turns merchant alerts on or off. Available on Starter plan and above.
• Alert Threshold — A slider that defines the inventory level at which you will receive an alert email (for example, 10 units).
• Send Alerts To — The email address where low stock alerts for your shop will be delivered.

When enabled, the app sends you an email notification whenever any product's inventory falls to or below your configured threshold. The alert is sent once per product variant — it will not repeat until inventory goes above the threshold and drops below it again.

5.4 Language and Localization

The app supports 18 languages for the customer-facing storefront widget (button, popup, success message). The available languages depend on your plan:

Full language list: English (GB), English (US), French, German, Spanish, Italian, Portuguese (PT), Portuguese (BR), Dutch, Polish, Swedish, Danish, Finnish, Norwegian, Japanese, Chinese (Simplified), Chinese (Traditional), Korean.

To change the language:

1. Use the User Interface Language dropdown in the top-right corner of the Settings page.
2. All text fields (button label, popup title, messages, etc.) update to show the translation for the selected language.
3. Edit any translation as needed.
4. Click Save Settings.

The language selection is saved as a preference. Your storefront widget will display content in the selected language to all visitors. Form validation messages (e.g., "Please enter your email") are also automatically translated.

5.5 Preview Mode

The Settings page includes a live preview panel on the right side. It has three preview tabs:

Changes you make in the Settings form are reflected in the preview in real time — no need to save first.

6. Analytics

The Analytics tab provides detailed insights into your notification and preorder performance.

6.1 Dashboard Stats

A summary of key metrics:

• Total Subscriptions — All signups received within the analytics retention window
• Notifications Sent — Successfully delivered emails
• Pending Notifications — Signups still waiting for restock
• Unsubscribed — Customers who opted out

6.2 Daily Trends

A chart showing daily signup and notification activity over time. The time range available depends on your plan's analytics retention:

6.3 Top Products

A ranked list of your products by number of back-in-stock signups. Use this to understand which products have the highest demand and should be prioritized for restocking.

6.4 Product-Level Analytics

Click into any product to see variant-level breakdowns:

• Number of signups per variant
• Pending vs. sent vs. unsubscribed counts
• Conversion rate per product

6.5 Preorder Analytics

The Analytics tab includes a dedicated Preorder section showing:

• Total preorder signups
• Preorder-to-order conversion (signed up → ordered)
• Preorder-to-paid conversion (ordered → paid)
• Top products by preorder demand

6.6 Exporting Subscriber Data

On the Starter plan and above, you can export your subscriber data as a CSV or JSON file. The export includes:

To export: Navigate to BIS Signups and use the export function. You can filter by status before exporting.

7. Subscription Plans and Billing

7.1 Plan Comparison

7.2 Free Plan

The Free plan is ideal for getting started and evaluating the app. It includes:

• 25 notification emails per month — Enough for very small stores or low-volume products.
• 10 preorder signups per month — Basic preorder functionality.
• Unlimited customer signups — There is no limit on how many customers can sign up for notifications.
• Basic button colors — The button uses the default black background with white text.
• English language — The storefront widget displays in English (GB) only.
• 7-day analytics retention — View the last 7 days of activity data.
• Low stock widget — Shows an "Only X left!" badge on low-inventory products.
• "Powered by RMS" branding — A small attribution link is shown below the signup form.

7.3 Starter Plan

The Starter plan ($4.90/month) unlocks more sending capacity and customization for growing stores:

• 500 emails per month — A substantial step up from the Free plan.
• 250 preorder signups per month — Room for growing preorder demand.
• Custom button colors — Match the notification button to your brand.
• All 18 languages — Full international support for the storefront widget.
• 30 days of analytics — A full month of performance insights.
• CSV + JSON data export — Download subscriber data for analysis.
• Low stock widget — Included, with full access to threshold, message, and badge colours.
• Merchant low-stock email alerts — Get notified when products run low.
• Collection badges — Show notification badges on collection pages.
• No branding — The "Powered by" attribution is removed from the popup and widget.

7.4 Growth Plan

The Growth plan ($14.90/month) adds more volume and advanced branding options:

• 2,500 emails per month — Suitable for medium to high-volume stores.
• 1,000 preorder signups per month — For stores with significant preorder demand.
• All customization options — Full control over button, popup, and email styling.
• All 18 languages — Full international support.
• 90-day analytics — Three months of historical performance data.
• Custom email sender domain — Send notifications from your own brand email (e.g., notifications@yourstore.com).
• Custom email templates — Full control over email HTML templates.
• Low stock widget — Included with all settings.
• Merchant low-stock email alerts — Included.
• Priority support — Faster response times.
• Webhook integrations — Connect notification and alert events to external services.

7.5 Enterprise Plan

For high-volume stores that need maximum flexibility and scale ($49.90/month):

• Unlimited emails — No monthly cap on notifications sent.
• Unlimited preorder signups — No cap on preorder interest collection.
• All 18 languages — Full global coverage.
• 1-year analytics retention — A full year of historical data for trend analysis.
• Custom email sender domain — Fully branded sending identity.
• Custom email templates — Unlimited.
• Low stock widget — Included.
• Merchant low-stock email alerts — Included.
• Priority support — Top-tier SLA and assistance.
• Webhook integrations — Included.
• API export — Programmatic access to subscriber data.

7.6 Annual Billing Discount

Save 20% by choosing annual billing:

Toggle between Monthly and Annual billing in Settings > Subscription & Billing using the billing interval switch. When Annual is selected, the app shows the annual price and the amount you save per year compared to paying monthly.

7.7 Free Trial

Every paid plan (Starter, Growth, Enterprise) includes a 7-day free trial. During the trial:

• You have full access to all features of the selected plan.
• You will not be charged until the trial period ends.
• You can downgrade to Free at any time before the trial ends to avoid charges.

From time to time, promotional pricing may apply to your first paid month after the trial (for example, a discounted first month on selected plans). Any such promotions will be clearly shown on the billing screen before you confirm the charge.

Each store gets one free trial. If you have already used a trial on a previous plan, future plan changes will not include a trial period.

7.8 Upgrading, Downgrading, and Cancelling

To upgrade: Go to Settings > Subscription & Billing, select a higher plan, and confirm. You will be redirected to Shopify's charge approval page. Once approved, the new plan takes effect immediately.

To downgrade: Select a lower plan (including Free). Your current email count resets and your features adjust to the new plan's limits immediately.

To cancel: Select the Free plan from the billing page, or use the Cancel button. Your subscription is cancelled immediately and you are moved to the Free plan. Your signup data is preserved.

All billing is handled through Shopify's built-in billing system. Charges appear on your regular Shopify invoice — no separate payment method is needed.

8. Mobile Experience

The storefront widget is fully responsive and adapts automatically to mobile devices:

• Inline button placement: On mobile (screens 768px and narrower), the notification button is fixed to the bottom of the screen as a full-width bar with a subtle shadow, ensuring it is always visible and easy to tap.
• Side buttons: Left and right edge buttons work the same on mobile as on desktop, remaining fixed to the screen edge.
• Popup: The signup popup is centered and scrollable on smaller screens.
• Premium popup (paid plans): On desktop, the premium popup displays a split-panel layout with the product image on the left and the form on the right. On mobile, this switches to a stacked vertical layout with the image on top.

No configuration is needed — the responsive behavior is automatic.

9. Privacy, GDPR, and Data Handling

RMS Preorder | Back in Stock is designed with privacy and compliance in mind.

Data collected from customers:

• Name
• Email address
• Phone number (optional, only if enabled)
• Salutation (optional, only if enabled)
• The product and variant they signed up for

GDPR compliance features:

Links to the app's Privacy Policy and Terms of Service are available in the Dashboard footer.

10. Frequently Asked Questions

Q: Does the button appear on products that are in stock? A: No. The button only appears when the selected variant has zero inventory. As soon as the variant becomes available, the button automatically disappears. If preorders are enabled and the product has the preorder tag, the preorder button appears regardless of stock status.

Q: What happens when I reach my monthly email limit? A: Pending notifications are preserved but will not be sent until your billing cycle resets or you upgrade to a higher plan. An upgrade prompt is shown on your Dashboard when you are approaching your limit.

Q: Can customers sign up for notifications even if I'm on the Free plan? A: Yes. Customer signups are unlimited on every plan, including Free. Only the number of outgoing notification emails is capped.

Q: How quickly are emails sent after restocking? A: Notification emails are sent within seconds of Shopify firing the inventory update webhook. In most cases, customers receive the email within 1–2 minutes of the restock.

Q: Can I customize the email design beyond the text? A: The email template includes a styled layout with your product image, price, variant name, and a "Shop Now" button that uses your configured button color. The text content (subject line and body) is fully customizable. On Growth and Enterprise plans, custom HTML email templates are available.

Q: What happens if I reinstall the app? A: Your trial history is preserved to prevent trial abuse, but you can continue using the app on the Free plan or subscribe to a paid plan. Previous subscriber data is deleted on uninstall per GDPR requirements.

Q: Does the button work with all Shopify themes? A: The button is designed to work with all Online Store 2.0 themes. It automatically detects the product form, variant selectors, and product data. Minor positioning variations may occur between themes. Use the Preview feature to verify the appearance on your theme.

Q: Are notification emails sent from my email address? A: By default, emails are sent from no-reply@reedmace.net. On the Growth and Enterprise plans, you can verify your own domain and send emails from a custom email address (e.g., notifications@yourstore.com).

Q: Where can I view the emails that were sent? A: The BIS Signups tab shows a complete history of all sent notifications with timestamps. Detailed email delivery analytics are available on paid plans.

Q: What does the low stock widget do? A: The low stock widget displays an urgency badge (for example, "Only 3 left!") on product pages when inventory falls below a threshold you configure. You can turn it on, set the threshold, customize the message (using {{count}} for the current stock level), and choose the badge colours in Settings > Button (Low Stock Widget card). The widget is available on all plans, including Free.

Q: How do preorder signups differ from back-in-stock signups? A: Back-in-stock signups capture demand for products that are currently sold out — customers are automatically emailed when the product is restocked. Preorder signups capture interest for products you tag as "preorder" — you can optionally allow customers to add the product directly to their cart for purchase before it ships.

Q: What is the preorder signup limit? A: Each plan has a monthly preorder signup limit: Free (10), Starter (250), Growth (1,000), Enterprise (unlimited). This is separate from the email notification limit.

11. Troubleshooting

The notification button does not appear on my product pages

1. Verify the app embed is enabled: Go to Online Store > Themes > Customize > App embeds and confirm that "Back in Stock Button" is toggled on.
2. Check that the product variant is actually out of stock (inventory quantity is 0).
3. Clear your browser cache and reload the product page.
4. Check the browser developer console (F12) for any JavaScript errors.

Customers are not receiving notification emails

1. Verify the product's inventory has actually increased from 0 to 1 or more. The webhook only fires on inventory level changes.
2. Check your email usage on the Dashboard — you may have reached your monthly limit.
3. If the product was restocked before the customer signed up, the webhook will not retroactively fire. Use the Notify button to manually send the email.
4. Check that the app has the read_inventory permission and the INVENTORY_LEVELS_UPDATE webhook is registered (this happens automatically during installation).

The popup styling does not match my theme

1. Use the Preview feature in Settings to check the appearance.
2. Adjust the button corner radius, padding, and colors to match your theme.
3. The popup inherits the body font from your theme for consistency.
4. Some theme CSS may override the popup styles. Contact support if you need assistance.

I changed my plan but the features have not updated

1. Refresh the Settings page.
2. If the billing approval page did not load, try clicking the plan button again.
3. Verify the plan change in your Shopify admin under Settings > Billing.

Preorder button is not appearing

1. Ensure preorder mode is enabled in Settings > Button > Preorder.
2. Verify the product has the correct preorder tag (must match exactly, including case).
3. Check that the app embed is enabled in your theme.

12. Support

Need help? Here is how to reach us:

• Documentation: reedmace.net/documentation/rms-back-in-store
• Email: info@reedmace.net
• Priority support: Available on Growth and Enterprise plans for faster response times.

We are committed to helping your store recover every possible sale. If you have feature requests, questions, or need help with setup, do not hesitate to reach out.

If you are enjoying the app, we would greatly appreciate a review on the Shopify App Store. Your feedback helps other merchants discover us and helps us continue improving the app.

RMS Preorder | Back in Stock is developed by Reedmace Software, a division of Wrenbys Ltd, London. All billing is processed securely through Shopify's built-in billing system.