Quick answer: Turn on inventory tracking for every product, set accurate starting quantities, use a low-stock alert (Shopify Flow can email you when quantity drops below a threshold), keep a small safety buffer on fast sellers, and decide in advance what happens when an item sells out. A weekly 15-minute inventory check prevents most overselling headaches.
Few things hurt a small store like selling something you don't have. The customer is annoyed, you're issuing refunds, and the review risk is real. The good news is that a few simple settings and habits prevent most of it.
1. Make sure tracking is on
For each product variant, check that Track quantity is enabled and the quantity matches reality. For service or digital products you don't need it, but for physical products it's essential. A product with tracking off is always "available," even at zero.
2. Start with accurate counts
Do a physical count, and update Shopify. Then keep one source of truth. If you also sell on marketplaces or in person, connect them so stock syncs, and don't edit quantities in two places.
3. Set what happens at zero
For each product, decide:
- Stop selling when out of stock (the default and safest).
- Continue selling when out of stock (backorder), only if you're sure you can fulfill soon, and say so clearly with an expected ship date.
- Hide the product if you won't restock it.
Be transparent about backorders. Customers forgive waiting; they don't forgive surprises.
4. Set up low-stock alerts
Shopify Flow, Shopify's free automation tool, can notify you when inventory falls below a threshold:
- Trigger: Inventory quantity changed.
- Condition: quantity is below your reorder point.
- Action: send an email or message to whoever orders stock.
We show more ideas, including hiding sold-out products, in 7 Shopify Flow automations.
5. Calculate a reorder point
A simple formula: (average daily sales × supplier lead time in days) + safety stock. If you sell 5 a day, your supplier takes 14 days and you want a 3-day cushion (15 units), your reorder point is (5 × 14) + 15 = 85. When stock hits 85, reorder.
6. Add a safety buffer for popular items
If you sell on several channels or get sudden spikes, hold back a few units from the available count so simultaneous orders don't oversell. This matters even more during promotions. See our Black Friday checklist.
7. Watch variants
A product can look in stock while the one size customers want is gone. Make sure sold-out variants show as unavailable, and consider a "notify me" option for popular items.
8. Handle returns and damaged goods
Restock returns that are sellable, and keep a separate record of damaged or unsellable items so your counts stay honest. Shopify's refund flow has a "restock" option. Use it deliberately.
9. Do a weekly check
- Sort products by lowest inventory and review the bottom ten.
- Check top sellers against expected demand this week.
- Look at any product with negative stock (a sign of overselling or a counting error).
- Place or schedule reorders.
Fifteen minutes is enough.
10. Communicate
When something sells out, say so honestly and offer an alternative or a restock date. Email subscribers who asked to be notified, since "back in stock" messages are some of the most effective emails you can send. Set up the flow in your email tool: see our email flow guide.
Common mistakes
- Leaving "continue selling when out of stock" on by accident.
- Editing counts in two systems that don't sync.
- Forgetting that inventory held at a third-party warehouse can create sales tax nexus. See sales tax basics.
- Not accounting for supplier delays.
Want help automating it?
We build and test Flow workflows for low-stock alerts, hiding sold-out items, tagging orders and more, and write a short guide so you can manage them. See our Shopify workflow automation, or request a quote.
Frequently asked questions
How do I get low-stock alerts in Shopify?
Use Shopify Flow with an inventory quantity changed trigger, a condition for your threshold and an email or message action.
How do I prevent overselling?
Track inventory, keep one source of truth across channels, hold a small safety buffer on fast sellers and stop selling at zero unless you can truly backorder.
What is a reorder point?
The stock level at which you should reorder: average daily sales times supplier lead time, plus safety stock.
Should I hide sold-out products?
Only if you won't restock them. Otherwise keep the page, show it as sold out and offer a back-in-stock notification.
Related services
- Shopify Workflow Automation with Shopify Flow – automate orders, stock alerts and tagging with Shopify Flow
- Monthly Shopify Store Management & Support – ongoing changes, fixes and check-ups each month
- Shopify Product Upload & Catalog Management – clean, consistent bulk product uploads
