diff --git a/Gruntfile.js b/Gruntfile.js
index 7ca42b19e06b..2ab99ca49fd8 100644
--- a/Gruntfile.js
+++ b/Gruntfile.js
@@ -43,6 +43,7 @@ module.exports = function(grunt) {
 
           'libtextsecure/crypto.js',
           'libtextsecure/storage.js',
+          'libtextsecure/storage/user.js',
           'libtextsecure/storage/devices.js',
           'libtextsecure/storage/groups.js',
           'libtextsecure/protobufs.js',
diff --git a/js/index.js b/js/index.js
index a5a5950bdf93..812d2a355298 100644
--- a/js/index.js
+++ b/js/index.js
@@ -19,7 +19,7 @@
     var bg = extension.windows.getBackground();
 
     window.Whisper = window.Whisper || {};
-    if (bg.textsecure.storage.getUnencrypted("number_id") === undefined) {
+    if (bg.textsecure.storage.user.getNumber() === undefined) {
         window.location = '/options.html';
     } else {
         new bg.Whisper.InboxView().$el.prependTo(bg.$('body',document));
diff --git a/js/libtextsecure.js b/js/libtextsecure.js
index af198dd377b1..5e733f43d013 100644
--- a/js/libtextsecure.js
+++ b/js/libtextsecure.js
@@ -38004,6 +38004,53 @@ window.axolotl.sessions = {
 })();
 
 
+/* vim: ts=4:sw=4
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+'use strict';
+
+;(function() {
+    /*********************************************
+    *** Utilities to store data about the user ***
+    **********************************************/
+    window.textsecure = window.textsecure || {};
+    window.textsecure.storage = window.textsecure.storage || {};
+
+    window.textsecure.storage.user = {
+        setNumberAndDeviceId: function(number, deviceId) {
+            textsecure.storage.putUnencrypted("number_id", number + "." + deviceId);
+        },
+
+        getNumber: function(key, defaultValue) {
+            var number_id = textsecure.storage.getUnencrypted("number_id");
+            if (number_id === undefined)
+                return undefined;
+            return textsecure.utils.unencodeNumber(number_id)[0];
+        },
+
+        getDeviceId: function(key) {
+            var number_id = textsecure.storage.getUnencrypted("number_id");
+            if (number_id === undefined)
+                return undefined;
+            return textsecure.utils.unencodeNumber(number_id)[1];
+        }
+    };
+})();
+
+
 /* vim: ts=4:sw=4
  *
  * This program is free software: you can redistribute it and/or modify
@@ -38213,7 +38260,7 @@ window.axolotl.sessions = {
             while (groupId === undefined || textsecure.storage.getEncrypted("group" + groupId) !== undefined)
                 groupId = getString(textsecure.crypto.getRandomBytes(16));
 
-            var me = textsecure.utils.unencodeNumber(textsecure.storage.getUnencrypted("number_id"))[0];
+            var me = textsecure.storage.user.getNumber();
             var haveMe = false;
             var finalNumbers = [];
             for (var i in numbers) {
@@ -38251,7 +38298,7 @@ window.axolotl.sessions = {
             if (group === undefined)
                 return undefined;
 
-            var me = textsecure.utils.unencodeNumber(textsecure.storage.getUnencrypted("number_id"))[0];
+            var me = textsecure.storage.user.getNumber();
             if (number == me)
                 throw new Error("Cannot remove ourselves from a group, leave the group instead");
 
@@ -38738,7 +38785,7 @@ textsecure.processDecrypted = function(decrypted, source) {
     if (decrypted.flags == null)
         decrypted.flags = 0;
 
-    if (decrypted.sync !== null && textsecure.utils.unencodeNumber(textsecure.storage.getUnencrypted("number_id"))[0] != source)
+    if (decrypted.sync !== null && textsecure.storage.user.getNumber() != source)
         throw new Error("Got sync context on a message not from a peer device");
 
     if ((decrypted.flags & textsecure.protobuf.PushMessageContent.Flags.END_SESSION)
@@ -38843,8 +38890,7 @@ window.textsecure.registerSingleDevice = function(number, verificationCode, step
     textsecure.storage.putUnencrypted("registrationId", registrationId);
 
     return textsecure.api.confirmCode(number, verificationCode, password, signalingKey, registrationId, true).then(function() {
-        var numberId = number + ".1";
-        textsecure.storage.putUnencrypted("number_id", numberId);
+        textsecure.storage.user.setNumberAndDeviceId(number, 1);
         textsecure.storage.putUnencrypted("regionCode", libphonenumber.util.getRegionCodeForNumber(number));
         stepDone(1);
 
@@ -38874,8 +38920,7 @@ window.textsecure.registerSecondDevice = function(encodedProvisionEnvelope, cryp
         textsecure.storage.putUnencrypted("registrationId", registrationId);
 
         return textsecure.api.confirmCode(identityKey.number, identityKey.provisioningCode, password, signalingKey, registrationId, false).then(function(result) {
-            var numberId = identityKey.number + "." + result.deviceId;
-            textsecure.storage.putUnencrypted("number_id", numberId);
+            textsecure.storage.user.setNumberAndDeviceId(identityKey.number, result.deviceId);
             textsecure.storage.putUnencrypted("regionCode", libphonenumber.util.getRegionCodeForNumber(identityKey.number));
             stepDone(2);
 
@@ -39084,7 +39129,7 @@ window.textsecure.api = function () {
         }
 
         if (param.do_auth) {
-            param.user      = textsecure.storage.getUnencrypted("number_id");
+            param.user      = textsecure.storage.user.getNumber() + "." + textsecure.storage.user.getDeviceId();
             param.password  = textsecure.storage.getEncrypted("password");
         }
 
@@ -39310,7 +39355,7 @@ window.textsecure.api = function () {
         var URL = URL_BASE.replace(/^http/g, 'ws') + url + '/?';
         var params = '';
         if (auth) {
-            var user = textsecure.storage.getUnencrypted("number_id");
+            var user = textsecure.storage.user.getNumber() + "." + textsecure.storage.user.getDeviceId();
             var password = textsecure.storage.getEncrypted("password");
             var params = 'login=%2B' + encodeURIComponent(user.substring(1)) + '&password=' + encodeURIComponent(password);
         }
@@ -39586,9 +39631,8 @@ window.textsecure.messaging = function() {
     }
 
     var sendSyncMessage = function(message, timestamp, destination) {
-        var numberDevice = textsecure.utils.unencodeNumber(textsecure.storage.getUnencrypted("number_id"));
-        var myNumber = numberDevice[0];
-        var myDevice = numberDevice[1];
+        var myNumber = textsecure.storage.user.getNumber();
+        var myDevice = textsecure.storage.user.getDeviceId();
         if (myDevice != 1) {
             var sync_message = textsecure.protobuf.PushMessageContent.decode(message.encode());
             sync_message.sync = new textsecure.protobuf.PushMessageContent.SyncMessageContext();
@@ -39600,7 +39644,7 @@ window.textsecure.messaging = function() {
 
     var sendGroupProto = function(numbers, proto, timestamp) {
         timestamp = timestamp || Date.now();
-        var me = textsecure.utils.unencodeNumber(textsecure.storage.getUnencrypted("number_id"))[0];
+        var me = textsecure.storage.user.getNumber();
         numbers = numbers.filter(function(number) { return number != me; });
 
         return new Promise(function(resolve, reject) {
diff --git a/js/options.js b/js/options.js
index 56d63e360ca2..6474a32dc07d 100644
--- a/js/options.js
+++ b/js/options.js
@@ -37,11 +37,7 @@
 
     $(function() {
         if (textsecure.registration.isDone()) {
-            $('#complete-number').text(
-                textsecure.utils.unencodeNumber(
-                    textsecure.storage.getUnencrypted("number_id")
-                )[0]
-            );//TODO: no
+            $('#complete-number').text(textsecure.storage.user.getNumber());
             $('#setup-complete').show().addClass('in');
             initOptions();
         } else {
diff --git a/js/register.js b/js/register.js
index ea9830f666f6..3775c0ff8a09 100644
--- a/js/register.js
+++ b/js/register.js
@@ -36,9 +36,9 @@
     var phoneView = new Whisper.PhoneInputView({el: $('#phone-number-input')});
     phoneView.$el.find('input.number').intlTelInput();
 
-    var number = textsecure.storage.getUnencrypted('number_id');
+    var number = textsecure.storage.user.getNumber();
     if (number) {
-        $('input.number').val(number.split('.')[0]);
+        $('input.number').val(number);
     }
 
     $('input.number').on('validation', function() {
@@ -98,7 +98,7 @@
         textsecure.storage.putUnencrypted('registrationId', registrationId);
         textsecure.storage.putEncrypted('signaling_key', signalingKey);
         textsecure.storage.putEncrypted('password', password);
-        textsecure.storage.putUnencrypted('number_id', number + '.1');
+        textsecure.storage.user.setNumberAndDeviceId(number, 1);
         textsecure.storage.putUnencrypted('regionCode', libphonenumber.util.getRegionCodeForNumber(number));
 
         log('verifying code');
diff --git a/js/views/conversation_view.js b/js/views/conversation_view.js
index 907f136708fe..380d808e8298 100644
--- a/js/views/conversation_view.js
+++ b/js/views/conversation_view.js
@@ -74,9 +74,7 @@
                 var view = new Whisper.KeyVerificationView({
                     model: {
                         their_key: textsecure.storage.devices.getIdentityKeyForNumber(number),
-                        your_key: textsecure.storage.devices.getIdentityKeyForNumber(
-                            textsecure.utils.unencodeNumber(textsecure.storage.getUnencrypted("number_id"))[0]
-                        )
+                        your_key: textsecure.storage.devices.getIdentityKeyForNumber(textsecure.storage.user.getNumber())
                     }
                 });
                 this.$el.hide();
diff --git a/js/views/message_detail_view.js b/js/views/message_detail_view.js
index 5152a2345b92..9b54ef22daba 100644
--- a/js/views/message_detail_view.js
+++ b/js/views/message_detail_view.js
@@ -58,9 +58,7 @@
             var view = new Whisper.KeyVerificationView({
                 model: {
                     their_key: textsecure.storage.devices.getIdentityKeyForNumber(number),
-                    your_key: textsecure.storage.devices.getIdentityKeyForNumber(
-                        textsecure.utils.unencodeNumber(textsecure.storage.getUnencrypted("number_id"))[0]
-                    )
+                    your_key: textsecure.storage.devices.getIdentityKeyForNumber(textsecure.storage.user.getNumber())
                 }
             });
             this.$el.hide();
diff --git a/libtextsecure/api.js b/libtextsecure/api.js
index 91dfcc0107ce..848731bad9cf 100644
--- a/libtextsecure/api.js
+++ b/libtextsecure/api.js
@@ -95,7 +95,7 @@ window.textsecure.api = function () {
         }
 
         if (param.do_auth) {
-            param.user      = textsecure.storage.getUnencrypted("number_id");
+            param.user      = textsecure.storage.user.getNumber() + "." + textsecure.storage.user.getDeviceId();
             param.password  = textsecure.storage.getEncrypted("password");
         }
 
@@ -321,7 +321,7 @@ window.textsecure.api = function () {
         var URL = URL_BASE.replace(/^http/g, 'ws') + url + '/?';
         var params = '';
         if (auth) {
-            var user = textsecure.storage.getUnencrypted("number_id");
+            var user = textsecure.storage.user.getNumber() + "." + textsecure.storage.user.getDeviceId();
             var password = textsecure.storage.getEncrypted("password");
             var params = 'login=%2B' + encodeURIComponent(user.substring(1)) + '&password=' + encodeURIComponent(password);
         }
diff --git a/libtextsecure/helpers.js b/libtextsecure/helpers.js
index 2f186b74af79..a074e1dd3b8d 100644
--- a/libtextsecure/helpers.js
+++ b/libtextsecure/helpers.js
@@ -161,7 +161,7 @@ textsecure.processDecrypted = function(decrypted, source) {
     if (decrypted.flags == null)
         decrypted.flags = 0;
 
-    if (decrypted.sync !== null && textsecure.utils.unencodeNumber(textsecure.storage.getUnencrypted("number_id"))[0] != source)
+    if (decrypted.sync !== null && textsecure.storage.user.getNumber() != source)
         throw new Error("Got sync context on a message not from a peer device");
 
     if ((decrypted.flags & textsecure.protobuf.PushMessageContent.Flags.END_SESSION)
@@ -266,8 +266,7 @@ window.textsecure.registerSingleDevice = function(number, verificationCode, step
     textsecure.storage.putUnencrypted("registrationId", registrationId);
 
     return textsecure.api.confirmCode(number, verificationCode, password, signalingKey, registrationId, true).then(function() {
-        var numberId = number + ".1";
-        textsecure.storage.putUnencrypted("number_id", numberId);
+        textsecure.storage.user.setNumberAndDeviceId(number, 1);
         textsecure.storage.putUnencrypted("regionCode", libphonenumber.util.getRegionCodeForNumber(number));
         stepDone(1);
 
@@ -297,8 +296,7 @@ window.textsecure.registerSecondDevice = function(encodedProvisionEnvelope, cryp
         textsecure.storage.putUnencrypted("registrationId", registrationId);
 
         return textsecure.api.confirmCode(identityKey.number, identityKey.provisioningCode, password, signalingKey, registrationId, false).then(function(result) {
-            var numberId = identityKey.number + "." + result.deviceId;
-            textsecure.storage.putUnencrypted("number_id", numberId);
+            textsecure.storage.user.setNumberAndDeviceId(identityKey.number, result.deviceId);
             textsecure.storage.putUnencrypted("regionCode", libphonenumber.util.getRegionCodeForNumber(identityKey.number));
             stepDone(2);
 
diff --git a/libtextsecure/sendmessage.js b/libtextsecure/sendmessage.js
index 98dd92567be7..bd231836b88b 100644
--- a/libtextsecure/sendmessage.js
+++ b/libtextsecure/sendmessage.js
@@ -256,9 +256,8 @@ window.textsecure.messaging = function() {
     }
 
     var sendSyncMessage = function(message, timestamp, destination) {
-        var numberDevice = textsecure.utils.unencodeNumber(textsecure.storage.getUnencrypted("number_id"));
-        var myNumber = numberDevice[0];
-        var myDevice = numberDevice[1];
+        var myNumber = textsecure.storage.user.getNumber();
+        var myDevice = textsecure.storage.user.getDeviceId();
         if (myDevice != 1) {
             var sync_message = textsecure.protobuf.PushMessageContent.decode(message.encode());
             sync_message.sync = new textsecure.protobuf.PushMessageContent.SyncMessageContext();
@@ -270,7 +269,7 @@ window.textsecure.messaging = function() {
 
     var sendGroupProto = function(numbers, proto, timestamp) {
         timestamp = timestamp || Date.now();
-        var me = textsecure.utils.unencodeNumber(textsecure.storage.getUnencrypted("number_id"))[0];
+        var me = textsecure.storage.user.getNumber();
         numbers = numbers.filter(function(number) { return number != me; });
 
         return new Promise(function(resolve, reject) {
diff --git a/libtextsecure/storage/groups.js b/libtextsecure/storage/groups.js
index 0ef55a11e2f0..e8039460d9e4 100644
--- a/libtextsecure/storage/groups.js
+++ b/libtextsecure/storage/groups.js
@@ -31,7 +31,7 @@
             while (groupId === undefined || textsecure.storage.getEncrypted("group" + groupId) !== undefined)
                 groupId = getString(textsecure.crypto.getRandomBytes(16));
 
-            var me = textsecure.utils.unencodeNumber(textsecure.storage.getUnencrypted("number_id"))[0];
+            var me = textsecure.storage.user.getNumber();
             var haveMe = false;
             var finalNumbers = [];
             for (var i in numbers) {
@@ -69,7 +69,7 @@
             if (group === undefined)
                 return undefined;
 
-            var me = textsecure.utils.unencodeNumber(textsecure.storage.getUnencrypted("number_id"))[0];
+            var me = textsecure.storage.user.getNumber();
             if (number == me)
                 throw new Error("Cannot remove ourselves from a group, leave the group instead");
 
diff --git a/libtextsecure/storage/user.js b/libtextsecure/storage/user.js
new file mode 100644
index 000000000000..c437201eb48d
--- /dev/null
+++ b/libtextsecure/storage/user.js
@@ -0,0 +1,45 @@
+/* vim: ts=4:sw=4
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+'use strict';
+
+;(function() {
+    /*********************************************
+    *** Utilities to store data about the user ***
+    **********************************************/
+    window.textsecure = window.textsecure || {};
+    window.textsecure.storage = window.textsecure.storage || {};
+
+    window.textsecure.storage.user = {
+        setNumberAndDeviceId: function(number, deviceId) {
+            textsecure.storage.putUnencrypted("number_id", number + "." + deviceId);
+        },
+
+        getNumber: function(key, defaultValue) {
+            var number_id = textsecure.storage.getUnencrypted("number_id");
+            if (number_id === undefined)
+                return undefined;
+            return textsecure.utils.unencodeNumber(number_id)[0];
+        },
+
+        getDeviceId: function(key) {
+            var number_id = textsecure.storage.getUnencrypted("number_id");
+            if (number_id === undefined)
+                return undefined;
+            return textsecure.utils.unencodeNumber(number_id)[1];
+        }
+    };
+})();