# Sell a Category in Multiples (Cases)

> Makes the total quantity from a category a multiple of a case size, for example 6 or 12 bottles, and explains how many more to add.

- Type: PHP
- Runs: Run everywhere
- Category: [WooCommerce](https://wpide.com/library/category/woocommerce/)
- Requires: WooCommerce
- Tags: woocommerce, quantity, categories, cases
- Author: WPIDE Team
- Installs: 0
- Updated: 2026-10-28
- Page: https://wpide.com/library/woo-category-sold-in-multiples/

## Code

```php
$wpide_case = array(
    'categories' => array( 'wine' ), // Category slugs.
    'size'       => 6,               // Case size.
);

add_action( 'woocommerce_check_cart_items', function () use ( $wpide_case ) {
    $count = 0;

    foreach ( WC()->cart->get_cart() as $item ) {
        if ( has_term( $wpide_case['categories'], 'product_cat', $item['product_id'] ) ) {
            $count += (int) $item['quantity'];
        }
    }

    $remainder = $wpide_case['size'] > 0 ? $count % $wpide_case['size'] : 0;

    if ( $count > 0 && $remainder ) {
        wc_add_notice( sprintf( 'These products are sold in cases of %1$d. Please add %2$d more to complete a case.', $wpide_case['size'], $wpide_case['size'] - $remainder ), 'error' );
    }
} );
```

## Notes

Different products in the category can be mixed within a case.

## How to use it

Install the free WPIDE plugin (https://wordpress.org/plugins/wpide/), find "Sell a Category in Multiples (Cases)" in its snippet library and add it in one click; or create a new PHP snippet in WPIDE (or any code snippets plugin) and paste the code above. More snippets: https://wpide.com/library/