---
title: Limit Cart to Single Vendor
description: "Add the below code in the functions.php file of your active theme to limit cart to single vendor ``` /** * Restrict the WooCommerce cart to products from one store. * * Store meta key: multivendorx_store_id * Variable products use…"
url: "https://multivendorx.com/docs/code-snippet/limit-cart-for-one-vendor/"
updated: "2026-10-12"
category: Order Management
---

# Limit Cart to Single Vendor

Add the below code in the functions.php file of your active theme to limit cart to single vendor

```
/**
 * Restrict the WooCommerce cart to products from one store.
 *
 * Store meta key: multivendorx_store_id
 * Variable products use their parent product's store ID.
 */

add_filter(
    'woocommerce_add_to_cart_validation',
    'restrict_cart_to_one_store',
    10,
    5
);

function restrict_cart_to_one_store(
    $passed,
    $product_id,
    $quantity,
    $variation_id = 0,
    $variations = array()
) {
    if ( ! $passed ) {
        return false;
    }

    // Resolve the product ID to its parent if it is a variation.
    $new_product_id = $variation_id
        ? wp_get_post_parent_id( $variation_id )
        : $product_id;

    if ( ! $new_product_id ) {
        $new_product_id = $product_id;
    }

    // Get the store ID of the new product.
    $new_store_id = get_post_meta(
        $new_product_id,
        'multivendorx_store_id',
        true
    );

    // Allow products without an assigned store ID.
    if ( $new_store_id === '' ) {
        return $passed;
    }

    // Check existing cart items.
    if ( ! WC()->cart || WC()->cart->is_empty() ) {
        return $passed;
    }

    foreach ( WC()->cart->get_cart() as $cart_item ) {
        $existing_product_id = $cart_item['product_id'];

        // Get the existing cart product.
        $existing_product = wc_get_product(
            $existing_product_id
        );

        if ( ! $existing_product ) {
            continue;
        }

        // Resolve variations to their parent product.
        $existing_parent_id = $existing_product->is_type( 'variation' )
            ? $existing_product->get_parent_id()
            : $existing_product_id;

        // Get the existing product's store ID.
        $existing_store_id = get_post_meta(
            $existing_parent_id,
            'multivendorx_store_id',
            true
        );

        // Prevent adding products from a different store.
        if (
            $existing_store_id !== '' &&
            (string) $existing_store_id !== (string) $new_store_id
        ) {
            wc_add_notice(
                'You can only purchase products from one store at a time. Please remove the existing store products from your cart before shopping at another store.',
                'error'
            );

            return false;
        }
    }

    return $passed;
}
```