Low Stock Alerts for Shopify: Setup Guide

Shopify shows you a "low stock" tag in the admin and a low-stock filter you can view manually — but it doesn't send you an email or notification when a product crosses that line. Nobody taps you on the shoulder. You find out you're low on stock when a customer tells you it's out. This guide covers what Shopify actually offers natively, why a low stock threshold isn't the same thing as a reorder point, and how to set up alerts that actually reach you before you run out.

What Shopify does — and doesn't — do natively

Shopify lets you set a "low stock" threshold per variant in Inventory settings. Once inventory drops below that number, the product shows a "Low stock" badge in your admin inventory list, and you can filter the inventory page to see everything currently below its threshold. That's genuinely useful — but it's a pull system, not a push system. You have to remember to go look. Nothing lands in your inbox.

The one native push option is Shopify Flow, an automation tool that can trigger an email or Slack message when inventory drops below a set number. Flow used to be a Plus-only feature, which is why a lot of older advice still says so, but it has been available on every paid plan since 2023. The catch is not access, it's that you build the workflow yourself and it fires on a fixed number you typed in — not on a reorder point that moves with your sales.

Setting up what's available natively

1. Set thresholds per variant. Go to each product's variant settings and enter a low stock threshold in the Inventory section. Do this for your top-selling SKUs first if you have a large catalogue — setting thresholds for everything at once is tedious and not necessary to start. If a variant isn't tracked yet, there's nothing for a threshold to watch; turn tracking on first.
2. Save a filtered admin view. In Products → Inventory, filter by "Low stock" and bookmark that URL. Check it on a schedule — daily for fast-moving SKUs, weekly for everything else.
3. Build a Flow workflow. Available on every paid plan. Use the "Inventory quantity changed" trigger with a condition checking whether the new quantity is below your threshold, and an action sending an email or Slack notification to whoever handles purchasing.

This gets you notified, but it has a real limitation worth understanding before you rely on it: a static threshold doesn't account for how fast a product is actually selling or how long it takes your supplier to restock it. That's the difference covered next.

Low stock threshold vs. reorder point — they're not the same thing

A low stock threshold is a fixed number you picked, probably once, possibly a while ago. A reorder point is calculated from your actual sales velocity and your supplier's actual lead time, and it changes as those numbers change. We cover the full formula in how to calculate reorder points, but the short version is:

Reorder Point = (Average daily sales × Lead time in days) + Safety stock

The practical problem with a fixed threshold: if a product's sales velocity doubles (a viral moment, a seasonal spike, a marketing push that worked), your old threshold is now too low — you'll get the alert too late, after you're already tighter on stock than the buffer accounts for. If velocity drops, the same threshold triggers alerts too early, and you over-order. A threshold set once and forgotten quietly drifts out of sync with reality on both ends.

This is why a threshold-based alert is a reasonable starting point but not where most growing stores stay. The next step up is software that recalculates your reorder point from live sales data automatically, so the alert always reflects current velocity rather than a number you set six months ago.

Comparing your app options

Worth knowing before you compare: low stock is one signal among several. Turnover, sell-through and days of cover tell you things a threshold never will, and we cover the metrics worth tracking beyond just low stock separately.

If native thresholds aren't cutting it, and building and maintaining a Flow workflow per threshold isn't how you want to spend your week, dedicated inventory apps handle this with varying levels of sophistication, from simple threshold alerts to full velocity-based forecasting. We compared the main options in detail in our Stocky alternatives comparison, which is worth reading in full if you're choosing between them, but the short version for alerts specifically:

• Simple threshold apps replicate what Shopify Flow does natively, just available on all plans — useful if you just need the notification and don't need forecasting.
• Velocity-based reorder apps calculate the reorder point formula automatically from your sales history and recalculate it as velocity changes, so the alert stays accurate without manual maintenance.
• Full demand forecasting tools go further, projecting future demand trends rather than just averaging recent sales — more than most stores under a few hundred SKUs actually need.

Our own app, StockCue, sits in the velocity-based category: it watches every SKU's sales velocity against its calculated reorder point and alerts you the day it's crossed, with a purchase order — supplier, quantity, cost — drafted and waiting for you to review rather than build from scratch. There's a free plan for stores under 50 SKUs if you want to try the alert mechanism itself before committing to anything.

A practical setup sequence

1. Start with your top 20% of SKUs by revenue. Set thresholds or reorder points for these first — they matter most and getting them wrong costs the most.
2. Calculate a real lead time for each supplier, not a guess. Check your last few purchase orders for how long they actually took from order to received stock.
3. Pick a safety stock buffer per SKU based on how volatile its sales are — 3–5 days of average sales for stable sellers, 7–14 days for spiky or unreliable-supplier SKUs.
4. Choose your alert method — native threshold and manual checking if you're under ~30 SKUs, a Flow workflow if you're happy maintaining fixed thresholds yourself, or a dedicated app if you want the calculation and the notification handled automatically.
5. Review and recalculate quarterly at minimum, monthly for your best sellers. Velocity drifts; a reorder point set once and never revisited eventually stops matching reality.

Frequently Asked Questions

Does Shopify have built-in low stock email alerts?

No. You can set a low stock threshold that shows a badge and a filter in the admin, but Shopify never emails you on its own. To get a message you either build a workflow in Shopify Flow, which is free on every paid plan, or install a third-party app.

What's the difference between a low stock alert and a reorder point alert?

A low stock alert fires when inventory crosses a number you chose manually, usually once. A reorder point alert fires when inventory crosses a number calculated from your actual sales velocity and supplier lead time, and that number updates automatically as your sales patterns change.

Do I need a third-party app to get low stock emails?

Not strictly. Shopify Flow is available on every paid plan and can email you when a variant drops below a number you set, so a free native route does exist if you are willing to build the workflow. Apps earn their place when you want the threshold calculated from sales velocity rather than typed in by hand.

How do I set a low stock threshold per product?

In your Shopify admin, go to the product, select the variant, and find the Inventory section — there's a "low stock" input field there for each variant's threshold.

What should I do once I get a low stock alert?

Ideally, the alert should give you enough lead time to place a purchase order before you actually run out — that's the point of calculating a proper reorder point rather than reacting to "almost out." Apps like StockCue draft the PO alongside the alert so the next step is reviewing and sending it, not starting from a blank spreadsheet.