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Ecommerce

Back-in-Stock & Reorder Alerts

Customers get notified on restock; you get alerted before you run out.

Saves about ~2 hrs per week

What it does

  • Captures waitlists on out-of-stock products
  • Notifies each waitlisted customer the moment it's back
  • Alerts you when inventory hits your reorder threshold
  • Suggests reorder quantities from sales velocity

How it works

  1. Product goes out of stock
  2. Waitlist captures interested customers
  3. Restock triggers automatic notifications
  4. Threshold alerts fire for reordering

What's included

  • Waitlist capture
  • Restock notifications
  • Reorder alerts

Set it up yourself

Follow these 4 steps in order. You will need accounts for: Shopify.

Step 1: Enable waitlists

  1. Turn on waitlist capture — most themes have 'Email me when back in stock' in the product page variant (check your theme settings).
  2. If your theme lacks it, use a small app or a form that saves to a sheet: Product, Variant, Email, Date.
  3. Test the waitlist capture on an out-of-stock product.
  4. Store the waitlist data in a sheet the workflow reads.
  5. Keep GDPR in mind — note the purpose when collecting.

Watch out: Capture variant-level (size/color), not just product-level — restock notifications for the wrong variant convert terribly.

Step 2: Connect inventory

  1. In Shopify admin API scopes, enable read_inventory (and write_inventory if you'll adjust levels).
  2. Create a custom app 'inventory-watch' with the token.
  3. In the workflow, query inventory levels for your products on a schedule (hourly).
  4. Map Product/Variant to its inventory quantity.
  5. Test the inventory read returns real numbers.

Watch out: Monitor at the variant level — a product read can show 'in stock' when the specific size a customer wants is empty.

Step 3: Set the reorder threshold

  1. In a sheet 'Reorder Rules' add: Product, Current Qty, Threshold (when to alert), Reorder Qty.
  2. In the workflow, compare inventory count to threshold each run.
  3. When qty ≤ threshold, fire the reorder alert to your email/Slack with the product and suggested qty.
  4. If you track sales velocity, compute suggested reorder = 2× weekly units sold.
  5. Test by lowering a threshold manually and watching the alert fire.

Watch out: Reorder quantity from velocity beats fixed numbers — a bestseller restocked at last quarter's quantity is a phantom stockout.

Step 4: Automate the notify

  1. When a product's inventory goes from 0 to >0 (restock), find waitlisted emails for that variant.
  2. Send each a 'Back in stock!' email with the product link.
  3. Remove those emails from the waitlist after notifying.
  4. Set the restock check hourly to catch restocks fast.
  5. Test end-to-end with a real restock.

Watch out: Send speed matters — a restock notification sent 8 hours late means the stock is often gone again by open time.

Frequently asked questions

What does the Back-in-Stock & Reorder Alerts automation do?

Customers get notified on restock; you get alerted before you run out. Captures waitlists on out-of-stock products

How much time does Back-in-Stock & Reorder Alerts save?

It is estimated to save ~2 hrs per week. Actual savings depend on your volume.

Which tools does Back-in-Stock & Reorder Alerts use?

It works with Shopify.

What does Back-in-Stock & Reorder Alerts include?

Waitlist capture, Restock notifications, Reorder alerts.

Can I set up Back-in-Stock & Reorder Alerts myself?

Yes. The do-it-yourself guide on this page walks through 4 steps, from getting access to testing the finished automation.