Frete grátis por região (faixa de cep) - Woocommerce

functions.php

<?php 
//Testa uma faixa de cep
function checkCpfRange($valor, $intervalos) {
	$v = (int) preg_replace("/\D+/", "", $valor);
	foreach ($intervalos as $range):
		list($min, $max) = $range;
		if ($v >= $min && $v <= $max)
			return true;
	endforeach;
	return false;
}

//Habilita o frete gratis caso o CEP esteja dentro das faixas permitidas
add_filter( 'woocommerce_package_rates', 'custom_woocommerce_correios_shipping_methods', 10, 2 );
function custom_woocommerce_correios_shipping_methods($rates, $package) {
	$intervalos = array(
		array('30000000', '39999999'), //MG
		array('20000000', '28999999'), //RJ
		array('01000000', '19999999'), //SP
		array('29000000', '29999999'), //ES
	);
	
	//Verify if any coupon is applied
	if(is_array(WC()->cart->applied_coupons) && count(WC()->cart->applied_coupons)>0){
		return $rates;
	}

	if (!checkCpfRange(WC()->customer->postcode, $intervalos)) {
		unset($rates['free_shipping']);
	}

	$states = array('SP', 'RJ', 'ES', 'MG');
	if (isset($rates['free_shipping']) && !in_array(WC()->customer->shipping_state, $states)) {
		unset($rates['free_shipping']);
	}

	if (isset(WC()->cart->subtotal) && WC()->cart->subtotal < 200) {
		unset($rates['free_shipping']);
	}

	return $rates;
}

?>