Check if "Ship to different address" has been checked in Woocommerce

May be the best way is to emulate it comparing for the order the billing and the shipping addresses. In most of all available related email notification hooks, the $order object is included as a parameter.

Here is an example with this function hooked in woocommerce_email_order_details action hook, that will display something different depending on that:

add_action( 'woocommerce_email_order_details', 'custom_content_email_order_details', 10, 4 );function custom_content_email_order_details( $order, $sent_to_admin, $plain_text, $email ){    // Only for "New Order" and admin email notification    if ( 'new_order' != $email->id && ! $sent_to_admin ) return;    // Displaying something related    if( $order->get_billing_address_1() != $order->get_shipping_address_1() ) {        echo '<p style="color:red;">Different billing and shipping addresses<p>';    } else {        echo '<p style="color:green;">Same billing and shipping addresses<p>';    }}

Code goes in function.php file of your active child theme (or theme) or also in any plugin file.

This code is tested in WooCommerce 3.1+ and works

You can also use (with different priorities) any of the following hooks in this code:
- woocommerce_email_before_order_table
- woocommerce_email_after_order_table
- woocommerce_email_order_meta
- woocommerce_email_customer_details

ahhh.. we can just check if $_POST['ship_to_different_address'] is set..

I needed the same kind of address checking and programmed myself a really good working solution which respects custom billing/shipping fields:

/** * Verify if the shipping address is different * * @param WC_Order $order * * @return bool */function is_different_shipping_address( WC_Order $order ): bool {    $billing_address  = $order->get_address();    $shipping_address = $order->get_address( 'shipping' );    if ( ! empty( $billing_address ) && ! empty( $shipping_address ) ) {        foreach ( $billing_address as $billing_address_key => $billing_address_value ) {            if ( isset( $shipping_address[ $billing_address_key ] ) ) {                $shipping_address_value = $shipping_address[ $billing_address_key ];                if ( ! empty( $billing_address_value ) && ! empty( $shipping_address_value ) && strcmp( $billing_address_value, $shipping_address_value ) !== 0 ) {                    return true;                }            }        }    }    return false;}

First I'm requesting both addresses from the order object. After that I'm looping over the billing address by default. Now I'm getting the same value from the shipping address (if set) and compare both values. If they are different, I'm returning true, else false.

Hoping it helps someone too.