What you configure
| Field | What it is |
|---|---|
| Rule ID | The exact ID of the rule to change, from its edit page rather than its name |
| Bound | Which number to change: min, max, multiple, minValue, maxValue, minWeight or maxWeight |
| New value | The number to set it to |
The ID is not optional and no name field exists. See Finding a rule's ID for Shopify Flow.
Before you build one
If what you want is a maximum that follows your stock level, check Stock-aware maximum rules first. It does that job inside the rule, with no workflow to build and no Flow run to debug.
This action earns its place when the signal comes from somewhere Prime MOQ cannot see: a date, a supplier feed, a spreadsheet, another app.
Five workflows worth building
Tighten a maximum as stock runs low. Trigger on Shopify's own inventory changed event, condition on stock below a threshold, then set the rule's maximum lower. This is the shipped "Low stock tightens the maximum" template in Ready-made workflow templates.
Loosen it back once restocked. The mirror image, and not bundled as a template. Same trigger, condition flipped to stock above a healthy number, action setting the maximum back to normal. Pair it with the first so the cap moves in both directions rather than only ratcheting down.
Tighten on a schedule for a flash sale. Flow's schedule trigger sets a tighter per-order cap just before a high-demand window opens, and a second scheduled workflow sets it back afterwards.
Raise a minimum for a seasonal wholesale push. A schedule trigger raises a value rule's minimum during a period when you want larger orders, with a second workflow returning it to normal.
Chain several bounds. Each step changes one bound, so put two or three steps back to back when one trigger should move both the minimum and the maximum of the same rule.
What it refuses
The action validates before it writes. It rejects a bound that does not exist on that rule's limit type, such as a weight bound on a quantity rule, and it rejects a value that would make the rule's own range impossible, such as a minimum above the existing maximum.
A rejection appears as a failed step in your Flow run log. Nothing is written and nothing fails silently.
Common mistakes
- Using the rule's name. The field takes an ID.
- Setting a bound the rule does not have. A quantity rule has no maxWeight to set.
- Building only the tightening direction. Nothing restores a bound unless you build the workflow that does it.
- Forgetting the multiple validation. If the rule sets a sell in multiples of value, a minimum or maximum written by this action still has to be an exact multiple of it. See Case packs and multiples.