How to Apply 50% Discount for Every Nth Order in WooCommerce?

BOGO offers often incentivize customers to purchase more items and likewise, this customization will help you to encourage repeat purchases. This code provides a 50% discount on the cart total for users who have made at least 10 orders and this discount gets repeated for every 10th order placed by that customer.

function ts_action_woocommerce_cart_calculate_fees($cart) {
    if (is_admin() && !defined('DOING_AJAX')) return;

    // Gets the current user's ID.
    $user_id = get_current_user_id();

    // User ID exists
    if ($user_id >= 1) {
        // Get the total orders by a customer.
        $order_count = wc_get_customer_order_count($user_id);

        // Starting from the 10th order
        if ($order_count >= 10 && $order_count % 10 == 0) {
            // Set the discount to 50%
            $discount = $cart->cart_contents_total * 0.5; // 50% discount

            // Only on cart page
            if (is_cart()) {
                // Message
                $message = sprintf(__('Congratulations! You have a 50%% discount applied. This is your %sth order', 'woocommerce'), $order_count + 1);

                // Check if a notice has already been added
                if (!wc_has_notice($message)) {
                    wc_clear_notices();
                    wc_add_notice($message, 'notice');
                }
            }

            // Set the discount (For discounts (negative fee) the taxes are always included)
            $cart->add_fee(__('Discount', 'woocommerce') . " (50%)", -$discount);
        }
    }
}
add_action('woocommerce_cart_calculate_fees', 'ts_action_woocommerce_cart_calculate_fees', 10, 1);

Output

Upon placing the 11th order, if a customer adds products to the cart, a 50% discount is applied based on the total amount in the cart. along with a notice message. The discount is applied for every set of 10 orders placed by the customer.

Similarly, you can also implement buy 2 get 50 off on second item in WooCommerce applying the discount to specific items based on the quantity.