Limit item order quantity for WooCommerce - Limit the quantity of an item that can be ordered. https://www.damiencarbery.com/2026/05/limit-item-order-quantity-for-woocommerce/

example-check-if-product-limited.php

<?php
add_filter( 'limit_order_quantity_product_limited', 'check_if_product_limited', 10, 2 );

// Check to see if this limit applies to this product.
// Return true if the product is quantity limited (to prevent adding more to the cart).
// Return false if there is no special quantity limit.
function check_if_product_limited( $limited, $product ) {
	// Hoodies category has ID 18.
	if ( in_array( 18, $product->get_category_ids() ) ) {
		return true;
	}
	return $limited;
}

example-set-product-order-limit.php

<?php
add_filter( 'limit_order_quantity_product_max_quantity', 'set_product_order_limit', 10, 2 );

// Set the quantity limit.
function set_product_order_limit( $limit, $product_id ) {
	// Hoodie with Zipper has a limit of 3.
	if ( 38 == $product_id ) { return 3; }

    // The limit is 2 for all other products with a limit so no further checks necessary.
    return 2;
}

limit-quantity-purchased-checks.php

<?php
/*
Plugin Name: Limit item order quantity - checks
Plugin URI: https://www.damiencarbery.com/2026/05/limit-item-order-quantity-for-woocommerce/
Description: Set the limitations on product purchase amounts, using the code in "Limit item order quantity" plugin.
Author: Damien Carbery
Version: 0.1.20260518
Requires Plugins: woocommerce, limit-quantity-purchased
*/


class LimitItemOrderQuantity_SetQty {
	public static $instance;


	// Initialize the plugin variables.
	public function __construct() {
        self::$instance = $this;

        $this->init();
	}


	// Set up WordPress specfic actions.
	public function init() {
		// Check to see if this limit applies to this product.
		add_filter( 'limit_order_quantity_product_limited', array( $this, 'check_if_product_limited' ), 10, 2 );

		// Set the quantity limit.
		add_filter( 'limit_order_quantity_product_max_quantity', array( $this, 'set_product_order_limit' ), 10, 2 );
	}


	// Check to see if this limit applies to this product.
	// Return true if the product is quantity limited (to prevent adding more to the cart).
	// Return false if there is no special quantity limit.
	public function check_if_product_limited( $limited, $product ) {
		// Hoodies category has ID 18.
		if ( in_array( 18, $product->get_category_ids() ) ) {
			return true;
		}
		return $limited;
	}


	// Set the quantity limit.
	public function set_product_order_limit( $limit, $product_id ) {
		// Hoodie with Zipper has a limit of 3.
		if ( 38 == $product_id ) { return 3; }

		// The limit is 2 for all other products with a limit so no further checks necessary.
		return 2;
	}
}
$LimitItemOrderQuantity_SetQty = new LimitItemOrderQuantity_SetQty();

limit-quantity-purchased.php

<?php
/*
Plugin Name: Limit item order quantity
Plugin URI: https://www.damiencarbery.com/2026/05/limit-item-order-quantity-for-woocommerce/
Description: Limit the quantity of an item that can be ordered (more than one, otherwise Sold Individually setting would be used).
Author: Damien Carbery
Version: 0.3.20260518
Requires Plugins: woocommerce
WC tested up to: 10.7
*/


class LimitItemOrderQuantity {
	public static $instance;


	// Returns an instance of this class. 
	public static function get_instance() {
		if ( null == self::$instance ) {
			self::$instance = new self;
		} 
		return self::$instance;
	}


	// Initialize the plugin variables.
	public function __construct() {
        self::$instance = $this;

        $this->init();
	}


	// Set up WordPress specfic actions.
	public function init() {
		// Limit the quantity that can be added to the cart.
		add_filter( 'woocommerce_add_to_cart_validation', array( $this, 'limit_quantity_allowed_add_to_cart' ), 10, 6 );
		// Limit the quantity that can be set when updating the cart.
		add_filter( 'woocommerce_update_cart_validation', array( $this, 'limit_quantity_allowed_update_cart' ), 10, 4 );
		// Limit the max quantity value that can be set in the quantity spinner field in the cart.
		add_filter( 'woocommerce_quantity_input_args', array( $this, 'limit_quantity_qty_field' ), 10, 2 );
	}


	// Check to see if this limit applies to this product.
	// Return true if the product is quantity limited (to prevent adding more to the cart).
	// Return false if there is no special quantity limit.
	private function check_if_product_is_quantity_limited( $product_id ) {
		$product = wc_get_product( $product_id );

		// If sold individually then don't set a different limit.
		if ( $product->is_sold_individually() ) {
			return false;
		}
		// No limit for virtual products - this is an opinionated decision that I am willing to remove.
		if ( $product->is_virtual() ) {
			return false;
		}

		return apply_filters( 'limit_order_quantity_product_limited', false, $product );
	}


	// Limit the quantity that can be added to the cart.
	public function limit_quantity_allowed_add_to_cart( $passed, $product_id, $quantity, $variation_id = 0, $variations = array(), $cart_item_data = array() ) {
		$product_cart_id = WC()->cart->generate_cart_id( $product_id, $variation_id, $variations, $cart_item_data );
		$cart_item_key = WC()->cart->find_product_in_cart( $product_cart_id );
		//error_log( sprintf( 'Validation: $product_id:%d, $product_cart_id:%s, $quantity:%d, $cart_item_key:%s, $passed:%s', $product_id, $product_cart_id, $quantity, var_export( $cart_item_key, true ), var_export( $passed, true ) ) );

		$max_allowed_quantity = apply_filters( 'limit_order_quantity_product_max_quantity', 0, $product_id );

		if ( $cart_item_key && $max_allowed_quantity && WC()->cart->cart_contents[ $cart_item_key ]['quantity'] >= $max_allowed_quantity ) {
			// Check to see if this limit applies to this product.
			if ( $this->check_if_product_is_quantity_limited( $product_id ) ) {
				$product = wc_get_product( $product_id );

				wc_add_notice( sprintf( 'You can only buy %d of <em>%s</em>.', $max_allowed_quantity, $product->get_name() ), 'error' );
				return false;
			}
		}
		return $passed;
	}


	// Limit the quantity that can be set when updating the cart.
	function limit_quantity_allowed_update_cart( $passed, $cart_item_key, $values, $quantity ) {
		//error_log( sprintf( 'Update cart: $id:%d, $cart qty:%d, $qty:%d', WC()->cart->cart_contents[ $cart_item_key ]['product_id'], WC()->cart->cart_contents[ $cart_item_key ]['quantity'], $quantity ) );

		$max_allowed_quantity = apply_filters( 'limit_order_quantity_product_max_quantity', 0, WC()->cart->cart_contents[ $cart_item_key ]['product_id'] );

		if ( $cart_item_key && $max_allowed_quantity && $quantity > $max_allowed_quantity ) {
			// Check to see if this limit applies to this product.
			if ( $this->check_if_product_is_quantity_limited( WC()->cart->cart_contents[ $cart_item_key ]['product_id'] ) ) {
				WC()->cart->set_quantity( $cart_item_key, $max_allowed_quantity, true );  // Set the quantity to the max allowed.
				$product = wc_get_product( WC()->cart->cart_contents[ $cart_item_key ]['product_id'] );
				wc_add_notice( sprintf( 'You can only buy %d of <em>%s</em>.', $max_allowed_quantity, $product->get_name() ), 'error' );
				return false;
			}
		}

		return $passed;
	}


	// Limit the max quantity value that can be set in the quantity spinner field in the cart.
	function limit_quantity_qty_field( $args, $product ) {
		if ( $this->check_if_product_is_quantity_limited( $product->get_id() ) ) {
			$max_allowed_quantity = apply_filters( 'limit_order_quantity_product_max_quantity', 0, $product->get_id() );
			
			if ( $max_allowed_quantity ) {
				$args['max_value'] = $max_allowed_quantity;
			}
		}

		return $args;
	}
}
$LimitItemOrderQuantity = new LimitItemOrderQuantity();