How product-specific purchase restrictions work

A product-specific Purchase Limit may require a customer to log in and limit how many items they can purchase during a sliding time window or their entire membership. The limit is checked at checkout against the customer's previous orders and the current quantity in the shopping cart.

How does the product-specific Purchase Limit work?

Product-specific Purchase Limit is based on four settings: Enablement, Login Requirement, Maximum Quantity, and Time Window in days. When the limit is enabled and Maximum Quantity is greater than zero, the checkout adds up the customer's previous acceptable order lines and the quantity of the same product in the shopping cart. The purchase is blocked if the total exceeds the limit.

The limit is checked on the server before payment and order creation. Canceled and returned orders are not counted in the purchase history. Time window 0 covers the entire ordered history; a positive number of days covers that rolling period backwards from the present. Purchase history is identified based on the logged-in customer account, so previous guest orders are not linked to a later registered account.

Enable Purchase Restriction for the product

The purchase restriction is implemented in the product editor:

1. Open Products /products .
2. Find the product and open its editor.
3. Go to the Advanced tab and look for Purchase Limit .
4. Turn on Enable purchase restriction .
5. Specify the login requirement, Maximum, and Time window in days.
6. Wait for the change to be saved before exiting the product.

The purchase limit fields are autosaved. Numeric values must be at least zero. If Enable purchase limit is not enabled, the checkout will skip the other purchase limit fields and the product will not be processed further.

Configure Purchase Limit fields

The purchase restriction fields work like this:

• Enable Purchase Limit activates all Purchase Limit checks for the product. Off preserves other settings, but the checkout will ignore them.
• Require sign-in prevents a guest from completing a purchase when the restriction is enabled.
• The maximum amount indicates the largest total amount for one customer account. A value of 0 means there is no limit.
• The time window in days defines the rolling period from which past purchases are calculated. A value of 0 means all past order history.

You can use a login-only requirement by enabling Require Login and leaving the Maximum Amount value at 0. If the Maximum Amount is greater than zero, it will also require a logged-in customer account, even if the separate Require Login switch is off. Without an account, the checkout will have no purchase history to associate with the customer.

Checkout and customer messages

The checkout Purchase Limit checks all items in the cart that have a limit applied. If a guest's cart contains an item that requires login or is limited in quantity, the checkout stops the progress and asks the customer to login to purchase that item.

For a logged-in customer, the checkout retrieves previous normal product lines for the same product from the customer account orders. It excludes lines from canceled and returned orders, limits purchases by the product Time Window, and adds the current quantity in the shopping cart. If the amount exceeds the Maximum Quantity, the customer receives an error message with the product name and the allowed quantity.

If the shopping cart contains the same product in multiple rows, the quantities in the rows are added together based on the product identifier. The message is displayed in the language used by the store. The limit does not reserve a quota in advance, but the estimate is based on the order history and cart visible at the time of checkout.

Examples of Purchase Restrictions

Examples from Purchasing Restrictions show how fields are associated with common use cases:

• Maximum 1 piece in 90 days: Maximum quantity 1 and Time window in days 90. The new piece fits into the limit when the previous purchase to be taken into account is outside the time window.
• Maximum 1 piece during the entire customer relationship: Maximum quantity 1 and Time window in days 0. All previous orders in the customer account, other than canceled or returned orders, are counted.
• For logged-in only with no quantity limit: Require login enabled and Maximum quantity 0. Purchase history does not limit quantity, but the guest cannot complete the purchase.
• Maximum 5 items in 30 days: Maximum quantity 5 and Time window 30 days. If the customer already has three items to be counted, the cart can hold a maximum of two more.

Test the new setting on a separate test customer. Check both the allowed limit case and the limit exceeded, as the limit applies to the total of previous purchases and the current cart, not just a single order.

Purchase restriction limits

Purchase limit limits are product and customer account specific. If the same rule is needed for multiple products, it is implemented for each product separately. Quantities from different products are not combined into a common quota.

A guest order cannot be linked to the subsequent purchase history of a logged-in customer in the context of this check. The restriction also does not identify the same person across different customer accounts. It is therefore not a blocking that verifies the connection between identity, household, company, or email addresses, but a rule based on the purchase history of a single customer account in the system.

When you change the Time Window or Maximum Amount, the new setting will affect the next checkout. Verify the change with your own product test and keep it clear in customer communications whether the limit is calculated for days or for the entire customer period.