Work down in order — the first two account for most cases.
1. The rule is not enabled
A saved rule is inert until its status is enabled. Open it and check.
This catches people who saved a draft meaning to come back, and people who disabled a rule while testing something else.
2. The scope is not what you think
| You set | It checks |
|---|---|
| Cart Min Quantity | Number of items |
| Cart Min Amount | Cart value |
| Product Min Quantity | Only the products you selected |
| Collection Min Quantity | Only items from that collection |
Quantity and amount are the pair most often confused. A 10-item minimum and a £200 minimum behave completely differently on a store with a wide price range.
For product and collection limits, confirm the cart actually contains the products the rule names — the limit does not apply otherwise.
3. You are testing a stale checkout
Close the tab, rebuild the cart, open checkout fresh.
4. The store has hit Shopify’s ceiling
Shopify allows 25 active validation functions per store across all apps. At the ceiling, new rules may not take effect. See limits.
5. It works for you but not for customers
If your own test passes and real customers still get through, the difference is in the cart, currency or customer — see works for me but not for customers.
Still stuck
Send support the rule title, a screenshot of the rule with its values visible, and a description of the cart that should have been blocked.