When something sells out in minutes, the question is who gets it. A per-product cap spreads a drop across more customers instead of a handful of carts.
Before you start
- Which products to cap, and at what number.
- Whether you want this permanently or only for a drop — you can pause the rule afterwards rather than delete it.
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. Go to Simple Order Limit → Create Rule.
3. Give the rule a title, and switch Enable/Disable Limit on. A rule that is saved but not enabled looks identical to one that is not working.
4. Open the Product tab, choose Product Max Quantity, and pick the products and set a cap for each.
5. Write the message, then save. Explaining the reason converts better than a flat refusal.
Verify it worked
- Cart above the cap for that product → blocked.
- Cart at the cap → completes.
- If the product has variants, test a cart mixing two variants and confirm the total behaves the way you expect.
Common setups
| Goal | Maximum |
|---|---|
| Limited edition drop | 1–2 per product |
| Anti-reseller on hyped lines | 2 |
| Free or heavily discounted samples | 1 |
| Rationed restock | 2–4 |
Pause the rule after the drop rather than deleting it — the next campaign usually wants the same setup, and a paused rule frees a slot against Shopify’s 25-rule ceiling.