---
title: "Shopify checkout validation rules"
slug: "shopify-pre-order-enforcement"
date: "2026-02-11T06:01:14+00:00"
modified: "2026-05-05T04:46:53+00:00"
author: "admin"
canonical: "https://preproduct.io/docs/shopify-pre-order-enforcement/"
---

> Shopify checkout validations are safeguards that ensures pre-order items are processed correctly. They’re powered by Shopify Functions and can’t be overridden by other apps.

### Available validations

You can run any combination of these validations — they’re fully compatible with each other.

#### **Pre-order enforcement**

When turned on, if a pre-order variant is detected without a valid **Shopify purchase option**, the checkout will be blocked, and the customer will be prompted to return to the product page to select the pre-order option.

**Note:** This feature is only compatible with setups using **charge-later**, **deposit-upfront**, or **charge-upfront** pre-orders powered by Shopify purchase options. Products on **capture-only** pre-order will just be ignored and never fail validation.

#### **Isolated pre-order cart enforcement**

When turned on, the rule checks the cart and ensures that pre-order items and regular buy-now items are not mixed together.

If the cart addition will result in both types of items, it will be blocked.

Turning on an [isolated pre-order redirect](https://preproduct.io/Docs/front-end-redirects) is the recommended way to require isolated carts, as it won’t show errors to customers. However, turning on this validation means the policy can not be circumvented.

Note: This feature is only compatible with setups using charge-later, deposit-upfront, or charge-upfront pre-orders. It does not apply to capture-only pre-orders.

### Activating and deactivating validations

To enable a validation, you must opt-in within both PreProduct and your Shopify admin settings.

**In PreProduct:**

1. Navigate to the **Setup** screen.
2. Scroll down to the **Shopify checkout validation** section.
3. Under the rule that you’d like to opt into, click **Activate**

After activating a validation, PreProduct will loop through all of your pre-order listings and add special managed metafields in Shopify. Depending on your catalogue size, this can take some time.

To deactivate a validation, simply click the red **Deactivate** button in the validation’s card.

*In the unlikely situation that PreProduct is down, you can always disable validations from Shopify, visit Shopify **Settings** -> **Checkout** -> Scroll to the bottom and click the three dots, followed by **Delete rule**.*

![](https://preproduct.io/wp-content/uploads/2026/02/activate-validation.gif)

### Failed validation customer experience

If a customer tries to add a pre-order item to their cart and it doesn’t pass an active validation rule, the item won’t be added. Shopify will also display an error message explaining what went wrong. Depending on your theme, that message may appear in one of the following ways:

1\. **Inline Error:** A warning message directly above the buy buttons.

![Inline validation error example](https://preproduct.io/wp-content/uploads/2026/02/setup-preorder-enforcement-inline-1-962x1024.png)Inline validation error example (styling dictated by Shopify theme)2\. **Modal Popup:** A “Transaction failed” pop-up explaining the specific pre-order issue.

![Pop-up validation error example](https://preproduct.io/wp-content/uploads/2026/02/setup-preorder-enforcement-modal-1-1024x559.png)Pop-up validation error example (styling dictated by Shopify theme)3\. **Silent failure:** We’ve observed that some older themes don’t surface any error messaging, and instead just stop the item being added to cart.