diff --git a/synapse/handlers/auth.py b/synapse/handlers/auth.py
index 620591b16..b273a4bee 100644
--- a/synapse/handlers/auth.py
+++ b/synapse/handlers/auth.py
@@ -321,7 +321,7 @@ class AuthHandler(BaseHandler):
         defer.returnValue(True)
 
     @defer.inlineCallbacks
-    def _check_threepid(self, medium, authdict, ):
+    def _check_threepid(self, medium, authdict):
         yield run_on_reactor()
 
         if 'threepid_creds' not in authdict:
diff --git a/synapse/rest/client/v1/login.py b/synapse/rest/client/v1/login.py
index 337ba5c02..77a0f00c5 100644
--- a/synapse/rest/client/v1/login.py
+++ b/synapse/rest/client/v1/login.py
@@ -19,13 +19,13 @@ from synapse.api.errors import SynapseError, LoginError, Codes
 from synapse.types import UserID
 from synapse.http.server import finish_request
 from synapse.http.servlet import parse_json_object_from_request
+from synapse.util.msisdn import phone_number_to_msisdn
 
 from .base import ClientV1RestServlet, client_path_patterns
 
 import simplejson as json
 import urllib
 import urlparse
-import phonenumbers
 
 import logging
 from saml2 import BINDING_HTTP_POST
@@ -61,8 +61,6 @@ def login_submission_legacy_convert(submission):
         del submission["medium"]
         del submission["address"]
 
-    return submission
-
 
 def login_id_thirdparty_from_phone(identifier):
     """
@@ -74,14 +72,8 @@ def login_id_thirdparty_from_phone(identifier):
     """
     if "country" not in identifier or "number" not in identifier:
         raise SynapseError(400, "Invalid phone-type identifier")
-    phoneNumber = None
-    try:
-        phoneNumber = phonenumbers.parse(identifier["number"], identifier["country"])
-    except phonenumbers.NumberParseException:
-        raise SynapseError(400, "Unable to parse phone number")
-    msisdn = phonenumbers.format_number(
-        phoneNumber, phonenumbers.PhoneNumberFormat.E164
-    )[1:]
+
+    msisdn = phone_number_to_msisdn(identifier["country"], identifier["number"])
 
     return {
         "type": "m.id.thirdparty",
@@ -173,7 +165,7 @@ class LoginRestServlet(ClientV1RestServlet):
         if "password" not in login_submission:
             raise SynapseError(400, "Missing parameter: password")
 
-        login_submission = login_submission_legacy_convert(login_submission)
+        login_submission_legacy_convert(login_submission)
 
         if "identifier" not in login_submission:
             raise SynapseError(400, "Missing param: identifier")
@@ -182,7 +174,7 @@ class LoginRestServlet(ClientV1RestServlet):
         if "type" not in identifier:
             raise SynapseError(400, "Login identifier has no type")
 
-        # convert phone type identifiers to geberic threepids
+        # convert phone type identifiers to generic threepids
         if identifier["type"] == "m.id.phone":
             identifier = login_id_thirdparty_from_phone(identifier)
 
diff --git a/synapse/rest/client/v2_alpha/account.py b/synapse/rest/client/v2_alpha/account.py
index 06bb3617e..199af60fc 100644
--- a/synapse/rest/client/v2_alpha/account.py
+++ b/synapse/rest/client/v2_alpha/account.py
@@ -20,13 +20,12 @@ from synapse.api.constants import LoginType
 from synapse.api.errors import LoginError, SynapseError, Codes
 from synapse.http.servlet import RestServlet, parse_json_object_from_request
 from synapse.util.async import run_on_reactor
+from synapse.util.msisdn import phone_number_to_msisdn
 
 from ._base import client_v2_patterns
 
 import logging
 
-import phonenumbers
-
 
 logger = logging.getLogger(__name__)
 
@@ -87,14 +86,7 @@ class MsisdnPasswordRequestTokenRestServlet(RestServlet):
         if absent:
             raise SynapseError(400, "Missing params: %r" % absent, Codes.MISSING_PARAM)
 
-        phoneNumber = None
-        try:
-            phoneNumber = phonenumbers.parse(body['phone_number'], body['country'])
-        except phonenumbers.NumberParseException:
-            raise SynapseError(400, "Unable to parse phone number")
-        msisdn = phonenumbers.format_number(
-            phoneNumber, phonenumbers.PhoneNumberFormat.E164
-        )[1:]
+        msisdn = phone_number_to_msisdn(body['country'], body['phone_number'])
 
         existingUid = yield self.hs.get_datastore().get_user_id_by_threepid(
             'msisdn', msisdn
@@ -273,14 +265,7 @@ class MsisdnThreepidRequestTokenRestServlet(RestServlet):
         if absent:
             raise SynapseError(400, "Missing params: %r" % absent, Codes.MISSING_PARAM)
 
-        phoneNumber = None
-        try:
-            phoneNumber = phonenumbers.parse(body['phone_number'], body['country'])
-        except phonenumbers.NumberParseException:
-            raise SynapseError(400, "Unable to parse phone number")
-        msisdn = phonenumbers.format_number(
-            phoneNumber, phonenumbers.PhoneNumberFormat.E164
-        )[1:]
+        msisdn = phone_number_to_msisdn(body['country'], body['phone_number'])
 
         existingUid = yield self.hs.get_datastore().get_user_id_by_threepid(
             'msisdn', msisdn
diff --git a/synapse/rest/client/v2_alpha/register.py b/synapse/rest/client/v2_alpha/register.py
index ad3c70814..95f9944c4 100644
--- a/synapse/rest/client/v2_alpha/register.py
+++ b/synapse/rest/client/v2_alpha/register.py
@@ -21,12 +21,12 @@ from synapse.api.auth import get_access_token_from_request, has_access_token
 from synapse.api.constants import LoginType
 from synapse.api.errors import SynapseError, Codes, UnrecognizedRequestError
 from synapse.http.servlet import RestServlet, parse_json_object_from_request
+from synapse.util.msisdn import phone_number_to_msisdn
 
 from ._base import client_v2_patterns
 
 import logging
 import hmac
-import phonenumbers
 from hashlib import sha1
 from synapse.util.async import run_on_reactor
 
@@ -110,14 +110,7 @@ class MsisdnRegisterRequestTokenRestServlet(RestServlet):
         if len(absent) > 0:
             raise SynapseError(400, "Missing params: %r" % absent, Codes.MISSING_PARAM)
 
-        phoneNumber = None
-        try:
-            phoneNumber = phonenumbers.parse(body['phone_number'], body['country'])
-        except phonenumbers.NumberParseException:
-            raise SynapseError(400, "Unable to parse phone number")
-        msisdn = phonenumbers.format_number(
-            phoneNumber, phonenumbers.PhoneNumberFormat.E164
-        )[1:]
+        msisdn = phone_number_to_msisdn(body['country'], body['phone_number'])
 
         existingUid = yield self.hs.get_datastore().get_user_id_by_threepid(
             'msisdn', msisdn