One Per Customer vs One Per Order: What's the Difference?

Purchase limit terminology can be confusing. "One per customer" and "one per order" sound similar but enforce very different rules. Choosing the wrong limit type undermines your campaign.

One per order

A per-order limit restricts quantity within a single checkout. For example, "maximum 2 per order" means a customer can buy 2 units in one transaction but can return later and buy 2 more.

Use when:

• Preventing bulk buying in a single transaction
• Managing cart size for high-demand items
• Allowing repeat purchases over time

Does not prevent: The same customer buying again in a separate order.

One per customer

A per-customer limit is designed to restrict repeat purchases across previous orders. When a shopper tries to buy the same limited product again, the rule checks for prior purchases and can block matching repeat attempts.

Use when:

• Limited product drops with scarce inventory
• Free sample campaigns
• First-purchase-only promotions
• Preventing abuse of one-time offers

Helps prevent: Matching repeat purchases across multiple orders.

Comparison table

Scenario	Per order	Per customer
Limited drop with one-purchase-per-customer rules	❌	✅
Max 3 units per checkout	✅	❌
Free sample campaign	❌	✅
Prevent cart stuffing	✅	❌

Per-customer limits help reduce matching repeat purchases, but no checkout rule can stop every intentional workaround if a shopper uses completely different checkout information.

Which does Limit Once enforce?

Limit Once is built for one-purchase-per-customer rules. It helps merchants block matching repeat purchase attempts for selected products during checkout, including guest checkout.

If you need per-order quantity caps, Shopify's native inventory or cart limit features may be more appropriate, depending on your use case.

Want to apply one-purchase-per-customer rules without custom code?

View Limit Once

Conclusion

Match your limit type to your business goal. For fair access to scarce or promotional products, per-customer limits are the right choice. For cart-size management, per-order limits suffice.