Apply automatically a coupon based on specific cart items count in Woocommerce

Question

I am trying to automatically trigger a coupon to be applied in the cart specifically for when there are 4 items in the cart.

The coupon is pre-created in the Woocom

Answer 1

There is some little mistakes and errors in your code. Try the following instead:

add_action( 'woocommerce_before_calculate_totals', 'auto_add_coupon_based_on_cart_items_count', 25, 1 );
function auto_add_coupon_based_on_cart_items_count( $cart ) {
    if ( is_admin() && ! defined( 'DOING_AJAX' ) )
        return;

    // Setting and initialising variables
    $coupon = 'tasterbox'; // <===  Coupon code
    $item_count = 4; // <===  <===  Number of items
    $matched    = false;

    if( $cart->cart_contents_count >= $item_count ){
        $matched = true; // Set to true
    }

    // If conditions are matched add coupon is not applied
    if( $matched && ! $cart->has_discount( $coupon )){
        // Apply the coupon code
        $cart->add_discount( $coupon );

        // Optionally display a message
        wc_add_notice( __('TASTER BOX ADDED'), 'notice');
    }
    // If conditions are not matched and coupon has been appied
    elseif( ! $matched && $cart->has_discount( $coupon )){
        // Remove the coupon code
        $cart->remove_coupon( $coupon );

        // Optionally display a message
        wc_add_notice( __('SORRY, TASTERBOX NOT VALID'), 'error');
    }
}

Code goes in function.php file of your active child theme (or active theme). Tested and works.