The situation
An independent homewares store in Newcastle with around 600 SKUs across three staff including the owner had a stockout problem they could not seem to solve. The owner reviewed stock levels manually each Monday morning, working through a spreadsheet and flagging products that needed reordering. The process was slow, relied on memory for which suppliers needed longer lead times, and consistently missed the reorder window for bestselling items during busy trading periods.
The consequence was predictable: popular items sold out, supplier emails went out late, and stock arrived after the demand peak had passed. Customers who asked about out-of-stock items were told to check back, which most did not. A 90-day comparison with the store's Shopify data showed that stockout periods on the top 40 SKUs were costing the business an estimated $4,800 a month in sales that simply never happened.
The flow we built
A Make.com automation now monitors Shopify inventory continuously and handles both sides of the stockout problem:
- When any product's inventory falls below its per-SKU reorder threshold (set once by the owner in a Google Sheet that acts as the reorder config), a supplier-specific reorder email goes out automatically with the product name, SKU, quantity to order, and the supplier's standard lead time.
- On any sold-out product page, customers can sign up for a back-in-stock notification. That signup is logged in a Shopify metafield and mirrored to a Google Sheet for the owner's visibility.
- When a restock arrives and Shopify inventory goes above zero, every customer on the waitlist for that product receives an automatic email with a link directly to the product page.
- The owner gets a weekly digest showing which products triggered reorder emails, how many customers are on each waitlist, and any products that have been out of stock for more than seven days without a reorder email being sent.
The platforms
Shopify for inventory data, product pages, and the customer-facing waitlist signup. Google Sheets as the reorder threshold config and waitlist mirror. Make.com for the automation logic, threshold checks, email delivery, and the weekly digest. The store is on a Professional Bot Care tier. When Shopify updated their webhook event naming conventions earlier in the year, the automation was patched without any interruption to reorder or waitlist emails.
The results
Tracking the 90 days following deployment against the 90 days prior, the store recovered an estimated $4,800 a month in previously lost sales. Stockout periods on the top 40 SKUs dropped significantly because reorder emails now go out the same day a threshold is crossed, not the following Monday. The back-in-stock waitlist converted at a strong rate: customers who signed up had already shown clear purchase intent.
The owner's Monday morning stock review still happens, but it shifted from operational triage to a five-minute scan of the weekly digest. The reorder process became a background function rather than a task that depended on finding the right moment in a busy retail week.
What this could look like for your retail business
If your store is losing sales to stockouts or missing the window to re-engage customers when popular items return, a Shopify-driven stock and waitlist flow adapts well across product categories. We build versions for homewares, fashion, specialty food, pet supplies, and other independent retail settings.