# Handle buyer checkout errors (/limited-release/commerce-platform/accept-payments/standard/customize/handle-buyer-checkout-errors)



Use `onError` callbacks and alternate checkout pages to handle buyer checkout errors..

## Know before you code [#know-before-you-code]

> **Info:** ### Paypal Checkout [#paypal-checkout]
>
> This feature modifies an existing PayPal Checkout integration and uses the following:
>
> * [JavaScript SDK:](/sdk/js/) Adds PayPal-supported payment methods.
> * [Orders REST API:](/api/orders/v2) Create, update, retrieve, authorize, and capture orders.
>
> [Paypal Checkout](/limited-release/commerce-platform/accept-payments/standard/)

> **Info:** ### Explore PayPal APIs with Postman [#explore-paypal-apis-with-postman]
>
> You can use Postman to explore and test PayPal APIs. Learn more in our [Postman guide](/api/rest/postman).

## Buyer checkout error [#buyer-checkout-error]

If an error prevents buyer checkout, alert the user that an error has occurred with the buttons using the `onError` callback.

```javascript lineNumbers
paypal.Buttons({
    onError: function(err) {
        // For example, redirect to a specific error page
        window.location.href = "/your-error-page-here";
    }
}).render('#paypal-button-container');
```

This error handler is a catch-all. Errors at this point are not expected to be handled beyond showing a generic error message or page.

## Script not loading error [#script-not-loading-error]

If null pointer errors prevent the script from loading, provide a different checkout experience.

```javascript lineNumbers
if (window.paypal && window.paypal.Buttons) {
    // render the buttons
} else {
    // show a fallback experience
}
```