How to limit quantity per order on Shopify

You usually need a limit for one of three reasons: a sale item you don’t want resellers to clear out, a product you can only make so many of, or stock you’re splitting fairly between customers. The setup is the same for all three. What matters is where the limit is checked.

Why most “limit” tricks don’t hold

There are three places a limit can live, and only one of them is safe:

So when you compare apps, ask one question: “Is the limit checked at checkout by a Shopify Function?” If the answer is vague, assume no.

The built-in option: B2B quantity rules

If you sell wholesale with Shopify’s B2B features, you already have quantity rules: a minimum, maximum and increment per product in a B2B catalog. They’re on the Basic, Grow, Advanced and Plus plans.

The catch is in the name. They only apply to buyers logged in as a company with that catalog. Your regular shoppers never see them, so they won’t help with a flash sale.

Set a maximum per order with OrderCap

This is our app, so take the recommendation with that in mind. Here’s the whole setup, start to finish. It takes about five minutes.

A maximum is checked twice: when the item is added to the cart, and again at checkout. A buyer who tries to put 3 in the cart is refused right away, with your message.

“Each product on its own” or “all together”?

This one setting causes most of the confusion, so here’s the difference with a maximum of 5:

• Each product on its own: every product gets its own 5. A buyer can take 5 of the serum and 5 of the cream.
• All of these products together: the products share one 5. Three serums and two creams, and they’re done.

Pick “together” when the products come from the same scarce supply, like four colors of a limited drop.

When several limits apply to the same product

You might have a collection-wide limit (“max 10 of anything in Sale”) and a tighter one for one product (“max 2 of the serum”). The most specific limit wins: a variant limit replaces the product limit, and a product limit replaces the collection limit. Whole-cart limits apply on top of all of them.

OrderCap won’t let you save two active rules that limit the same product at the same level, and it tells you which rule already has it. That prevents the classic “why is my limit 3 when I set 2?” mystery.

OrderCap by Centubo. Min, max and pack limits on any product, checked at checkout, plus payment rules like hiding COD on big orders. Free during launch.

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Write a message people won’t argue with

The default message is clear (“You can buy up to 2 of Flash Sale Serum per order”), but a reason helps. Buyers accept a limit when they understand it. Under Messages at checkout you can write your own, with {max} and {product} filled in for you:

Launch batch is small: up to {max} of {product} per order so more people get one.

If you sell in several languages, add a translation per checkout language in the same section.

Show the limit before checkout

Nobody likes finding out about a rule on the payment page. Add the OrderCap limits block to your product page in the theme editor (Online Store > Themes > Customize, then Add block in the product section). It shows “Max 2 per order” next to the quantity field. It’s only a hint, though. The real check stays at checkout, so the limit holds even on a page where you forget the block.

Test it before your sale starts

Don’t let your first customer be your tester. Run through this list:

1. Add the product 3 times on the product page. The cart should refuse the third.
2. Click Buy it now with a quantity of 3, if your theme shows a quantity field next to it. Checkout should show your message and block payment.
3. Try an express button (Shop Pay, PayPal). Same result.
4. Add 2 and complete a test order. It should go through. On a development store, use Shopify’s Bogus Gateway.

You can also build a cart in OrderCap’s simulator to see the exact message a buyer would get, without placing an order.

What a per-order limit can’t do

Be honest with yourself about these before the sale:

• It resets every order. A determined buyer can place two orders of 2. If that matters, keep an eye on orders with the same address in the first hour, or cancel and refund duplicates. Your sale terms can say you’ll do that.
• It doesn’t reserve stock. If you have 50 units and a max of 2, the 26th buyer still gets nothing. Limits spread stock out. They don’t create more.
• Orders you create yourself in the admin aren’t limited. The rule is for buyers checking out, not for you.