diff --git a/dom/phonenumberutils/PhoneNumber.jsm b/dom/phonenumberutils/PhoneNumber.jsm
index 849fe639d2a8..e22941a72481 100644
--- a/dom/phonenumberutils/PhoneNumber.jsm
+++ b/dom/phonenumberutils/PhoneNumber.jsm
@@ -306,8 +306,9 @@ this.PhoneNumber = (function (dataBase) {
     // Remove formating characters and whitespace.
     number = PhoneNumberNormalizer.Normalize(number);
 
-    // If there is no defaultRegion, we can't parse international access codes.
-    if (!defaultRegion && number[0] !== '+')
+    // If there is no defaultRegion or the defaultRegion is the global region,
+    // we can't parse international access codes.
+    if ((!defaultRegion || defaultRegion === '001') && number[0] !== '+')
       return null;
 
     // Detect and strip leading '+'.
@@ -317,6 +318,11 @@ this.PhoneNumber = (function (dataBase) {
     // Lookup the meta data for the given region.
     var md = FindMetaDataForRegion(defaultRegion.toUpperCase());
 
+    if (!md) {
+      dump("Couldn't find Meta Data for region: " + defaultRegion + "\n");
+      return null;
+    }
+
     // See if the number starts with an international prefix, and if the
     // number resulting from stripping the code is valid, then remove the
     // prefix and flag the number as international.
diff --git a/dom/phonenumberutils/PhoneNumberUtils.jsm b/dom/phonenumberutils/PhoneNumberUtils.jsm
index 478e6f67905a..a3239a40ac10 100644
--- a/dom/phonenumberutils/PhoneNumberUtils.jsm
+++ b/dom/phonenumberutils/PhoneNumberUtils.jsm
@@ -29,8 +29,14 @@ XPCOMUtils.defineLazyServiceGetter(this, "gIccService",
 #endif
 
 this.PhoneNumberUtils = {
-  init: function() {
+
+  initParent: function() {
     ppmm.addMessageListener(["PhoneNumberService:FuzzyMatch"], this);
+    this._countryNameCache = Object.create(null);
+  },
+
+  initChild: function () {
+    this._countryNameCache = Object.create(null);
   },
   //  1. See whether we have a network mcc
   //  2. If we don't have that, look for the simcard mcc
@@ -131,13 +137,31 @@ this.PhoneNumberUtils = {
   },
 
   parseWithMCC: function(aNumber, aMCC) {
+    if (DEBUG) debug("parseWithMCC " + aNumber + ", " + aMCC);
     let countryName = MCC_ISO3166_TABLE[aMCC];
     if (DEBUG) debug("found country name: " + countryName);
     return PhoneNumber.Parse(aNumber, countryName);
   },
 
-  parseWithCountryName: function(aNumber, countryName) {
-    return PhoneNumber.Parse(aNumber, countryName);
+  parseWithCountryName: function(aNumber, aCountryName) {
+    if (this._countryNameCache[aCountryName]) {
+      return PhoneNumber.Parse(aNumber, aCountryName);
+    }
+
+    if (Object.keys(this._countryNameCache).length === 0) {
+      // populate the cache
+      let keys = Object.keys(MCC_ISO3166_TABLE);
+      for (let i = 0; i < keys.length; i++) {
+        this._countryNameCache[MCC_ISO3166_TABLE[keys[i]]] = true;
+      }
+    }
+
+    if (!this._countryNameCache[aCountryName]) {
+      dump("Couldn't find country name: " + aCountryName + "\n");
+      return null;
+    }
+
+    return PhoneNumber.Parse(aNumber, aCountryName);
   },
 
   isPlainPhoneNumber: function isPlainPhoneNumber(aNumber) {
@@ -205,6 +229,8 @@ if (inParent) {
   XPCOMUtils.defineLazyServiceGetter(this, "ppmm",
                                      "@mozilla.org/parentprocessmessagemanager;1",
                                      "nsIMessageListenerManager");
-  PhoneNumberUtils.init();
+  PhoneNumberUtils.initParent();
+} else {
+  PhoneNumberUtils.initChild();
 }
 
diff --git a/dom/phonenumberutils/tests/test_phonenumberutils.xul b/dom/phonenumberutils/tests/test_phonenumberutils.xul
index 6303b60210b3..1ee69b7e693d 100644
--- a/dom/phonenumberutils/tests/test_phonenumberutils.xul
+++ b/dom/phonenumberutils/tests/test_phonenumberutils.xul
@@ -47,6 +47,26 @@ function ParseWithMcc(dial, mcc) {
   }
 }
 
+function ParseWithCountryName(dial, countryName) {
+  var result = PhoneNumberUtils.parseWithCountryName(dial, countryName);
+  if (result) {
+    ok(true, "Parses!\n");
+  } else {
+    ok(false, "Should Parse");
+    dump("expected: parses");
+  }
+}
+
+function CantParseWithCountryName(dial, countryName) {
+  var result = PhoneNumberUtils.parseWithCountryName(dial, countryName);
+  if (result) {
+    ok(false, "Should not Parse");
+    dump("expected: does not parse!\n");
+  } else {
+    ok(true, "Expected Parsing error!\n");
+  }
+}
+
 function FuzzyMatch(number1, number2, expect) {
   var result = PhoneNumberUtils.fuzzyMatch(number1, number2);
   is(result, expect, "FuzzyMatch OK!");
@@ -56,6 +76,12 @@ function FuzzyMatch(number1, number2, expect) {
 CantParseWithMcc("1234", 123);
 ParseWithMcc("4165555555", 302);
 
+ParseWithCountryName("4155123456", "US");
+CantParseWithCountryName("4155123456", "001");
+CantParseWithCountryName("4155123456", "XXY");
+ParseWithCountryName("4155123456", "US");
+
+
 is(PhoneNumberUtils.normalize("123abc", true), "123", "NumbersOnly");
 is(PhoneNumberUtils.normalize("123abc", false), "123222", "NumbersOnly");