# Adding a Checkout Validation
The Shopify checkout rule acts as the final safeguard against invalid orders. Even if the customer bypasses earlier warnings on the product or cart pages, this rule ensures that no unauthorized purchases can slip through.
If a customer tries to check out with a cart that violates the limits you’ve set—whether by visiting the checkout URL directly or ignoring the earlier notifications—this Checkout Rule will prevent them from completing their purchase. It acts as a reliable barrier, ensuring your order limits are strictly enforced no matter how the customer attempts to proceed.
By setting this up, you protect your store from unexpected bulk purchases, avoid shipping complications, and keep your inventory balanced.
## Step 1: Accessing the Checkout validation
You can enable this option by checking the box in your settings. When selected, all customers will be able to complete the checkout process without any restrictions from limit rules.
**How to enable:**
1. Go to `Setings > Checkout validation`
2. Tick the checkbox **Allow all customers to complete checkout**.
## Step 2: Configuring the Checkout rules
* Click **Enable checkout validation** in the app.
* You will be redirected to the **Checkout** page in Shopify.
* Scroll down to the **Checkout Rules** section and click **Add rule**.
* A modal window will appear where you can configure the rule settings.
* In the **Rule settings**, tick the checkbox **Allow all customers to complete checkout**.
* Click **Save** to confirm your rule.
## Step 3: Turn on the checkout rule
After saving your settings, ensure the checkout rule is enabled. To do this, locate the switch or toggle next to the checkout rule you've just configured and turn it on
{% hint style="success" %}
It is recommended to check the option: "Allow all customers to complete checkout".
{% endhint %}
After saving, your checkout rule for cart-checkout validation should appear as follows as the customer has an invalid cart.
