How to Buy Product A and Product B with a Total Minimum Quantity and Get a Free Product C in WooCommerce?

If you are selling wholesale items in your online store, then at some point you will be using some BOGO offers that help to drive sales. This code snippet will offer a free product C when purchasing a combination of products A and B with a total minimum quantity of 5.

Let’s consider an example scenario where the store sells the latest smart home devices. If a customer purchases smart light bulbs (Product A) and smart plugs (Product B) from an electronics retailer. The promotion indicates that if you acquire a minimum of 5 items, combining both the smart bulbs and plugs as needed, you’ll receive a voice-controlled virtual assistant device (Product C) at no cost.

add_action('template_redirect', 'ts_add_gift_id_in_cart');

function ts_add_gift_id_in_cart() {
    if (is_admin()) return;
    if (WC()->cart->is_empty()) return;

    $product_a_id = 100;
    $product_b_id = 911;
    $product_gifted_id = 470;
    $min_combined_qty_required = 5;

    // Get quantities of Product A and Product B in cart
    $qty_product_a = WC()->cart->get_cart_item_quantities()[$product_a_id];
    $qty_product_b = WC()->cart->get_cart_item_quantities()[$product_b_id];

    // Calculate the combined quantity
    $combined_qty = $qty_product_a + $qty_product_b;

    // Check if the combined quantity meets the minimum requirement
    if ($combined_qty >= $min_combined_qty_required) {
        // Check if the free product is not already in the cart
        $product_gifted_cart_id = WC()->cart->generate_cart_id($product_gifted_id);
        $product_gifted_in_cart = WC()->cart->find_product_in_cart($product_gifted_cart_id);

        // If the free product is not in the cart, add it
        if (!$product_gifted_in_cart) {
            WC()->cart->add_to_cart($product_gifted_id);
        }
    } else {
        // If the minimum combined quantity requirement is not met, remove the free product if present
        $product_gifted_in_cart = WC()->cart->find_product_in_cart($product_gifted_id);
        if ($product_gifted_in_cart) {
            WC()->cart->remove_cart_item($product_gifted_in_cart);
        }
    }
}

Output

When a customer buys smart home devices in bulk quantities and if the quantity of those specified products meet the threshold of the minimum combined quantity (A+B), the code automatically adds the complimentary product ‘smart speaker ‘ to the cart.

Until the combined quantity threshold of product A and Product B is not met, the free Product C will not be added to the cart as shown below.

Alternatively, you can also fix BOGO offers based on individual product quantity as well. This post will help you to add a BOGO offer for a fixed quantity in WooCommerce.