diff --git a/pyicloud/base.py b/pyicloud/base.py
index 23e774e..739e7bc 100644
--- a/pyicloud/base.py
+++ b/pyicloud/base.py
@@ -8,7 +8,8 @@ from pyicloud.exceptions import PyiCloudFailedLoginException
 from pyicloud.services import (
     FindMyiPhoneServiceManager,
     CalendarService,
-    UbiquityService
+    UbiquityService,
+    ContactsService
 )
 
 
@@ -72,6 +73,12 @@ class PyiCloudService(object):
         )
         self.params.update({'id': sha.hexdigest().upper()})
 
+        clientId = str(uuid.uuid1()).upper()
+        self.params.update({
+            'clientBuildNumber': '14E45',
+            'clientId': clientId,
+        })
+
     def authenticate(self):
         """
         Handles the full authentication steps, validating,
@@ -126,6 +133,11 @@ class PyiCloudService(object):
         service_root = self.webservices['calendar']['url']
         return CalendarService(service_root, self.session, self.params)
 
+    @property
+    def contacts(self):
+        service_root = self.webservices['contacts']['url']
+        return ContactsService(service_root, self.session, self.params)
+
     def __unicode__(self):
         return 'iCloud API: %s' % self.user.get('apple_id')
 
diff --git a/pyicloud/services/__init__.py b/pyicloud/services/__init__.py
index 3911d9b..4befaf7 100644
--- a/pyicloud/services/__init__.py
+++ b/pyicloud/services/__init__.py
@@ -1,3 +1,4 @@
 from pyicloud.services.calendar import CalendarService
 from pyicloud.services.findmyiphone import FindMyiPhoneServiceManager
 from pyicloud.services.ubiquity import UbiquityService
+from contacts import ContactsService
diff --git a/pyicloud/services/contacts.py b/pyicloud/services/contacts.py
new file mode 100644
index 0000000..9208df7
--- /dev/null
+++ b/pyicloud/services/contacts.py
@@ -0,0 +1,49 @@
+from __future__ import absolute_import
+import os
+import uuid
+from datetime import datetime
+from calendar import monthrange
+
+
+class ContactsService(object):
+    """
+    The 'Contacts' iCloud service, connects to iCloud and returns contacts.
+    """
+    def __init__(self, service_root, session, params):
+        self.session = session
+        self.params = params
+        self._service_root = service_root
+        self._contacts_endpoint = '%s/co' % self._service_root
+        self._contacts_refresh_url = '%s/startup' % self._contacts_endpoint
+        self._contacts_changeset_url = '%s/changeset' % self._contacts_endpoint
+
+    def refresh_client(self, from_dt=None, to_dt=None):
+        """
+        Refreshes the ContactsService endpoint, ensuring that the
+        contacts data is up-to-date.
+        """
+        host = self._service_root.split('//')[1].split(':')[0]
+        self.session.headers.update({'host': host})
+        params_contacts = dict(self.params)
+        params_contacts.update({
+            'clientVersion': '2.1',
+            'locale': 'en_US',
+            'order': 'last,first',
+        })
+        req = self.session.get(self._contacts_refresh_url, params=params_contacts)
+        self.response = req.json()
+        params_refresh = dict(self.params)
+        params_refresh.update({
+            'prefToken': req.json()["prefToken"],
+            'syncToken': req.json()["syncToken"],
+        })
+        self.session.post(self._contacts_changeset_url, params=params_refresh)
+        req = self.session.get(self._contacts_refresh_url, params=params_contacts)
+        self.response = req.json()
+
+    def all(self):
+        """
+        Retrieves all contacts.
+        """
+        self.refresh_client()
+        return self.response['contacts']