A PHP Function to retrieve state from zip code in Brazil / Função PHP para retornar a sigla do estado dado um CEP

getBrazilStateFromZipCode.php

<?php

function getBrazilStateFromZipCode($cep = '') {
	$cepNum = intval(preg_replace("/[^0-9]/", "", $cep));
	if ($cepNum >= 69900000 && $cepNum <= 69999999) {
		return "AC";
	} else if ($cepNum >= 57000000 && $cepNum <= 57999999) {
		return "AL";
	} else if ($cepNum >= 69000000 && $cepNum <= 69299999) {
		return "AM";
	} else if ($cepNum >= 69400000 && $cepNum <= 69899999) {
		return "AM";
	} else if ($cepNum >= 68900000 && $cepNum <= 68999999) {
		return "AP";
	} else if ($cepNum >= 40000000 && $cepNum <= 48999999) {
		return "BA";
	} else if ($cepNum >= 60000000 && $cepNum <= 63999999) {
		return "CE";
	} else if ($cepNum >= 70000000 && $cepNum <= 72799999) {
		return "DF";
	} else if ($cepNum >= 73000000 && $cepNum <= 73699999) {
		return "DF";
	} else if ($cepNum >= 29000000 && $cepNum <= 29999999) {
		return "ES";
	} else if ($cepNum >= 72800000 && $cepNum <= 72999999) {
		return "GO";
	} else if ($cepNum >= 73700000 && $cepNum <= 76799999) {
		return "GO";
	} else if ($cepNum >= 65000000 && $cepNum <= 65999999) {
		return "MA";
	} else if ($cepNum >= 30000000 && $cepNum <= 39999999) {
		return "MG";
	} else if ($cepNum >= 79000000 && $cepNum <= 79999999) {
		return "MS";
	} else if ($cepNum >= 78000000 && $cepNum <= 78899999) {
		return "MT";
	} else if ($cepNum >= 66000000 && $cepNum <= 68899999) {
		return "PA";
	} else if ($cepNum >= 58000000 && $cepNum <= 58999999) {
		return "PB";
	} else if ($cepNum >= 50000000 && $cepNum <= 56999999) {
		return "PE";
	} else if ($cepNum >= 64000000 && $cepNum <= 64999999) {
		return "PI";
	} else if ($cepNum >= 80000000 && $cepNum <= 87999999) {
		return "PR";
	} else if ($cepNum >= 20000000 && $cepNum <= 28999999) {
		return "RJ";
	} else if ($cepNum >= 59000000 && $cepNum <= 59999999) {
		return "RN";
	} else if ($cepNum >= 76800000 && $cepNum <= 76999999) {
		return "RO";
	} else if ($cepNum >= 69300000 && $cepNum <= 69399999) {
		return "RR";
	} else if ($cepNum >= 90000000 && $cepNum <= 99999999) {
		return "RS";
	} else if ($cepNum >= 88000000 && $cepNum <= 89999999) {
		return "SC";
	} else if ($cepNum >= 49000000 && $cepNum <= 49999999) {
		return "SE";
	} else if ($cepNum >= 01000000 && $cepNum <= 19999999) {
		return "SP";
	} else if ($cepNum >= 77000000 && $cepNum <= 77999999) {
		return "TO";
	} else {
		throw new Exception("CEP nao esta dentro de uma faixa de estados do Brasil");
	}
}