I have the code below, I have it setup so each product has the following fields: shipping_national_free_shipping - checkbox shipping_national_one_item_cost - number field shipping_national_additional_items_cost - number field If shipping_national_free_shipping is disabled, the code below works out the shipping cost and adds it to the product. That works. However if shipping_national_free_shipping is enabled and there are still values in the other two fields it still adds the shipping cost when it should ignore those fields when shipping_national_free_shipping is enabled. function kraftdeck_national_shipping_cost_logic($cart) { if (is_admin() && !defined('DOING_AJAX')) { return; } error_log('Starting national shipping cost logic...'); $customer_shipping_country_code = WC()->customer->get_shipping_country(); $customer_shipping_country = kraftdeck_get_full_country_name($customer_shipping_country_code); foreach ($cart->get_cart() as $cart_item_key => $cart_item) { $product_id = $cart_item['product_id']; $national_free_shipping = get_field('shipping_national_free_shipping', $product_id); // Check if national free shipping is enabled ('enabled' in array) if (!empty($national_free_shipping) && in_array('enabled', (array)$national_free_shipping)) { continue; } $country_of_origin = get_field('shipping_country_of_origin', $product_id); if ($customer_shipping_country === $country_of_origin) { $shipping_national_one_item_cost = get_field('shipping_national_one_item_cost', $product_id); $shipping_national_additional_items_cost = get_field('shipping_national_additional_items_cost', $product_id); $quantity = $cart_item['quantity']; $additional_shipping_cost = 0; if (is_numeric($shipping_national_one_item_cost)) { if (empty($shipping_national_additional_items_cost)) { $additional_shipping_cost = $shipping_national_one_item_cost * $quantity; } else { $additional_shipping_cost = $shipping_national_one_item_cost + $shipping_national_additional_items_cost * ($quantity - 1); } } if ($additional_shipping_cost > 0) { $base_price = $cart_item['data']->get_price(); $new_price = ($base_price * $quantity) + $additional_shipping_cost; $cart_item['data']->set_price($new_price / $quantity); } } error_log("Final Additional Shipping Cost for Product $product_id: $additional_shipping_cost"); error_log("Final Price for Product $product_id: " . $cart_item['data']->get_price()); } } add_action('woocommerce_before_calculate_totals', 'kraftdeck_national_shipping_cost_logic'); function kraftdeck_get_full_country_name($country_code) { $countries = WC()->countries->get_countries(); $full_name = isset($countries[$country_code]) ? $countries[$country_code] : ''; // Remove any parentheses and content within them $full_name_cleaned = preg_replace('/\s+(.+)$/', '', $full_name); return $full_name_cleaned; } remove_action('woocommerce_after_shop_loop_item_title', 'woocommerce_template_loop_price', 10); I've tried everything to get this working, even ChatGPT cannot help!