Define a minimum order amount for WooCommerce

custom-woocommerce-minimum-order-amount.php

<?php

// Check the minimum amount when the order is processed.
add_action( 'woocommerce_checkout_process', 'custom_woocommerce_minimum_order_amount' );
// Check the minimum amount on the cart page.
add_action( 'woocommerce_before_cart', 'custom_woocommerce_minimum_order_amount' );
// Check the minimum amount on the mini cart.
add_action( 'woocommerce_before_mini_cart', 'custom_woocommerce_minimum_order_amount' );

/**
 * Define a minimum order amount for WooCommerce
 *
 * @author Ramon Ahnert <https://profiles.wordpress.org/rahmohn/>
 */
function custom_woocommerce_minimum_order_amount() {
	// Set this variable to specify a minimum order value.
	$minimum = 50;

	if ( 1 < did_action( 'woocommerce_before_mini_cart' ) ) {
		return;
	}

	if ( WC()->cart->total < $minimum ) {
		$message = sprintf(
			// translators: %1$s cart total; %2$s minimum order amount.
			__( 'Your current order total is %1$s — you must have an order with a minimum of %2$s to place your order' ),
			wc_price( WC()->cart->total ),
			wc_price( $minimum )
		);

		if ( is_cart() ) {
			wc_print_notice( $message, 'error' );
		} else {
			wc_add_notice( $message, 'error' );
		}
	}
}