On a Shopify store, there are cases where you want to set a one-item-per-customer purchase limit when selling limited or popular products. This limit gives more customers a chance to purchase and helps maintain fairness. This article introduces, in simple, step-by-step fashion, how to set up a one-item-per-customer limit using a Shopify app.
This time we'll use the Shopify app "RuffRuff Order Limits," but the blog article below introduces how to set up a one-item-per-customer limit using "RuffRuff 予約販売." Please use it as a reference.
What Is a One-Item-Per-Customer Limit?
In this article, a "one-item-per-customer limit" refers to restricting purchases so that a given customer account can buy no more than one unit of a specific product.
Result of a One-Item-Per-Customer Limit
Configuring the setup described in this article results in the following product behavior.
Depending on a customer's membership status, the product behaves as follows:
- Guest → ❌️ Cannot purchase
- Member (not yet purchased) → ⭕️ Can purchase
- Member (already purchased) → ❌️ Cannot purchase
There's a demo product where this article's setup has actually been implemented, so if you want to check how it behaves, feel free to use it as a reference.
How to Set Up a One-Item-Per-Customer Limit
Preparation. Install the Shopify Apps
This time, we'll introduce how to implement a "one-item-per-customer purchase limit" using the Shopify apps "RuffRuff Order Limits" and "Shopify Flow," so if you haven't installed these apps yet, please install them via the links below.
RuffRuff Order Limits
"RuffRuff Order Limits" is a Shopify app that provides an all-in-one solution for every kind of purchase restriction — quantity limits, spending limits, bundling restrictions, customer restrictions, payment restrictions, and access restrictions.
It's the first Shopify app in Japan built on the Cart and Checkout Validation API, achieving server-side handling of order restriction processing that previously could only be handled on the front end. As a result, it delivers a more robust order restriction system that's harder to bypass compared to existing order-limit apps.
What Is Shopify Flow?
Shopify Flow is Shopify's own native app that automates all sorts of tasks and processes that come up in running a Shopify store. It used to only be available on the Premium plan, but since July 2023 it's also been available starting from the Basic plan. Shopify Flow can be installed for free from the Shopify App Store. It's a service similar to automation tools like Zapier or IFTTT.
Step 1. Create a Quantity Rule
First, in RuffRuff Order Limits, set up a quantity limit so a product can only be purchased in quantities of 1 per order.
(1) Click "Quantity Rules" in the app's left-hand menu
(2) Click "Create rule"
(3) Set the maximum quantity to 1
(4) Under target products, select the product(s) you want to set up the "one-item-per-customer limit" for
(5) Click "Save"
※ Feel free to change the title, product message, scope, and alert message as needed.
Step 2. Create a Customer Rule
Next, in RuffRuff Order Limits, set up a customer restriction so only members who don't have a "purchased" customer tag can buy the product.
(1) Click "Customer Rules" in the app's left-hand menu
(2) Click "Create rule"
(3) Check "Require an account"
ℹ️ If you want to allow guest checkout, leave this unchecked. Note that if you allow guest checkout, the app's validation will only run at the checkout page.
(4) Check "Prohibit purchases from customers with the tag(s) below"
(5) In the input field below, enter "purchased"
(6) Under target products, select the product(s) you want to set up the "one-item-per-customer limit" for
※ Feel free to change the title, product message, scope, and alert message as needed.
(7) Click "Save"
Step 3. Create a Workflow That Tags the Customer at the Time of Purchase
Finally, in Shopify Flow, create a workflow that automatically adds a "purchased" customer tag to the buyer at the time of purchase.
(1) Open Shopify Flow and click "Create workflow"
(2) Set the trigger to "Order Created"
(3) Set a condition to identify the product you want to set up the "one-item-per-customer limit" for
(Variables useful for identifying the product)
・Product ID: order/LineItems/product/id
・Product name: order/LineItems/product/title
・Product tags: order/LineItems/product/tags
・Variant ID: order/LineItems/variant/id
・Variant name: order/LineItems/variant/title
・SKU: order/LineItems/variant/sku
※ In the attached image, the condition checks whether the SKU matches
(4) For the action, choose "Add Customer Tags" and set the tag to add as "purchased"
(5) Turn the workflow on
In Closing
With the steps above, you can set up a one-item-per-customer purchase limit on your Shopify store. This setup automatically restricts purchases of a specific product to one unit per member, and maintains a state where only members who haven't yet purchased can buy it.
This method is especially effective for selling limited-edition or promotional products. Offering a fair purchase opportunity can also help improve customer satisfaction and boost repeat rates.
By making use of Shopify's flexible features and apps, you can implement a wide range of sales strategies. Feel free to customize this approach to fit your own sales strategy and put it to use in running an effective ecommerce store.
