Can Shopify Flow send low stock emails? What it does, and where it stops
Yes. Shopify Flow can send an internal email when a variant's inventory falls below a number you type into the condition, so if you want a low stock email built inside Shopify itself, that is the workflow to build. Where Flow stops is the number: it compares stock against a static threshold you supply, and has no view of how fast a SKU sells or how long your supplier takes.
Flow automates the action, not the arithmetic
Shopify Flow is Shopify's own automation tool. It works in three parts: a trigger, a condition, an action. Point the trigger at inventory. Compare the remaining quantity against a number. Finish with an internal email action. That is a low stock email running inside Shopify, with no third-party app in the path.
Confirm the exact trigger and action names in Shopify's Flow documentation before you build. The triggers, conditions and actions on offer depend on your store and on the apps you have installed. Shopify is the only reliable source for what yours has today.
What Flow leaves with you is the number in the condition. It is a static value you type in. Flow compares stock against it. It does not derive it, and it holds no record of how many units a SKU sells in a day or how long your supplier takes. Whatever you enter stands until you edit it.
This page is about Flow specifically. Shopify's own built-in low stock settings, and the full set of native routes sitting next to an app, have their own pages in this section.
Where the number comes from, if not from Flow
A reorder point is the stock level at which an order placed now arrives before the shelf is empty. The arithmetic is plain. Take average daily sales over a recent window. Multiply by your supplier's lead time. Add a buffer for the weeks that misbehave.
Restoc is built to do that per SKU rather than ask you for a figure. It installs through Shopify OAuth and reads inventory levels and sales history through webhooks plus a scheduled sync job. From there it calculates a reorder point from a sales velocity window, the lead time held for that SKU, and a store-wide safety stock percentage. The full working is set out on the reorder points page in this section, and the alert side, including why one crossing produces one message rather than one per inventory event, is on the email alerts page.
Lead times without typing hundreds of rows
Lead times are the input merchants dread. Restoc pulls each SKU's vendor from the Shopify product's vendor field on sync, and shows it on the dashboard and the weekly report. A vendor lead times screen holds one lead time per supplier. It fills every SKU that has no lead time of its own. You set a supplier's timing once.
What sits alongside the alert
Two things a Flow email has no equivalent for. A dashboard showing current stock, days of inventory remaining, safety stock in units and reorder status per active SKU. And a weekly reorder report listing every SKU below its reorder point with a suggested order quantity, exportable as CSV. Both have their own pages here.
So the mechanical difference is a single one.
- Flow fires on a fixed number that you supply and maintain.
- Restoc fires on a number calculated from that SKU's own sales, its supplier's lead time and your safety stock setting.
The decision is who maintains the number
Flow costs you nothing and it is already in your admin. So the question is not which tool is cleverer. It is how much upkeep you are willing to carry.
One number across ten SKUs is fine. You know that stock by heart. You will notice when a threshold goes stale. At two hundred SKUs the picture changes. Demand moves with the season. A supplier adds two weeks. A slow mover turns into a fast one. The threshold you set in March is quietly wrong by June, and nothing breaks loudly. The email simply arrives too late, or arrives for a SKU you did not need to think about.
Three questions settle it:
- How many SKUs would need a threshold, and how often would you go back and revisit them?
- Does demand on your best sellers hold steady, or does it come in bursts?
- Do your lead times vary enough that a fixed number stops meaning the same thing month to month?
If the answers are small, steady and no, build the Flow workflow and spend your time elsewhere. If they are not, the number is the work, and the number is the part Flow hands back to you.
Questions
Can Shopify Flow send low stock emails?
Yes. Flow is Shopify's automation tool, and sending an internal email is one of the actions it can take. Trigger on an inventory change. Add a condition comparing the remaining quantity to a number. Finish with the email action. Check Shopify's Flow documentation for the exact trigger and action names, because what you can use depends on your store and your installed apps.
What does the workflow actually look like?
Three parts. The trigger watches for inventory changing on a variant. The condition asks whether the remaining quantity sits at or below the number you chose. The action sends the email to whichever address you put in. It runs on Shopify's side, so no third-party tool sits in the path. Shopify's documentation is the place to confirm how each part is configured.
Will Flow tell me when to reorder, or only when stock is low?
It compares stock to the number you supplied. That answers the low stock question, not the reorder question. Twelve units is comfortable for a slow mover and already late for something selling five a day on a three week lead time. Flow has no input for sales velocity or lead time, so that calculation sits with you. Restoc is built to compute a reorder point per SKU instead, and the reorder points page sets out how.
What about SKUs that sell in bursts rather than evenly?
A fixed threshold treats a burst and a steady trickle the same way. The only thing it reads is the current quantity. An average-based reorder point has the same weakness on its own, which is why merchants add a buffer by hand. Restoc is built to apply a store-wide safety stock percentage on top of lead-time demand, and to show that buffer in units on the dashboard, the weekly report and the CSV export.
Will Flow email me more than once for the same SKU?
A workflow runs when its trigger fires, so a SKU moving around the threshold can trigger it repeatedly. Shopify's Flow documentation is the place to look for how to hold repeat sends back on your store, using conditions, tags or scheduling. Restoc takes the other route: alerts go out through an idempotent background job, so one threshold crossing sends one alert per channel. The email alerts page covers it.
Can Flow set a different threshold for every SKU?
One workflow with one number in its condition applies that number to everything it matches. Varying it means using product data such as tags or metafields in the condition, or building more than one workflow. Shopify's documentation sets out what is supported. Restoc holds a lead time per SKU, filled from a per-supplier lead time where a SKU has none of its own, and derives each SKU's reorder point from its own sales. The velocity window is store-wide on Starter and Growth, with a per-SKU override on Pro.
Can Flow send the alert to Slack instead of email?
Flow's action list includes connectors to other tools, and what you get depends on which apps your store has installed. Check Shopify's Flow documentation for the current list. If your ordering conversation happens in Slack, check that before you build an email-only workflow. Restoc is built to email reorder alerts on every plan, sent through Amazon SES to your account email address until you change it in Settings > Alerts. Slack alerts through a webhook you configure start on Growth, at $59 a month for up to 1,000 tracked SKUs. Starter is email only, and we would rather say so plainly.
Can I use Restoc today, and what will it cost?
Not yet. Restoc is on a waitlist while the app is finished, and there is no launch date to quote. The plans are set. Starter is $29 a month for up to 200 tracked SKUs with email alerts. Growth is $59 for up to 1,000 SKUs, adding Slack alerts alongside email. Pro is $99 for up to 2,000 SKUs with a per-SKU velocity window override. Each carries a 60 day free trial. Yearly billing is ten months' price for twelve months, at $290, $590 and $990. Every plan covers one location, and billing runs on your Shopify invoice rather than a separate card payment.