Before you start
- The app embed enabled — see install.
- A decision on what you are limiting and to what number.
Steps
1. Install Nex Validator
Search Nex Validator in the Shopify App Store, or use the button below. Approve the permissions and the app appears in your admin under Apps. There is a free trial, and it works on every Shopify plan.
2. From the dashboard, choose Simple Order Limit → Create Rule.
3. Give the rule a Title. It is required, and it is what you will navigate by later — Minimum 3 items per order beats Rule 1.
4. Pick the limit you want and enter its value. The form groups them:
| Group | Limits |
|---|---|
| Cart Quantity / Amount | Cart min/max quantity, cart min/max amount |
| Product Quantity | Product min/max quantity |
| Collection Quantity | Collection min/max quantity |
5. Write the Custom error message. This is what a blocked customer reads, so say what to change — “Orders start at 3 items” beats “Invalid cart”.
6. Set Status to Enabled and save.
Verify it worked
- Build a cart that breaks the rule and go to checkout — payment is blocked and your message appears.
- Build a cart that satisfies it — checkout completes normally.
Reload checkout between tests. A tab opened before you saved keeps its old state, which reads exactly like the rule not working.
Next
- All the limit types, one page each
- Messages — what customers see and where