diff --git a/resources/sql/autopatches/20190116.contact.01.number.sql b/resources/sql/autopatches/20190116.contact.01.number.sql
new file mode 100644
--- /dev/null
+++ b/resources/sql/autopatches/20190116.contact.01.number.sql
@@ -0,0 +1,10 @@
+CREATE TABLE {$NAMESPACE}_auth.auth_contactnumber (
+  id INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
+  phid VARBINARY(64) NOT NULL,
+  objectPHID VARBINARY(64) NOT NULL,
+  contactNumber VARCHAR(255) NOT NULL COLLATE {$COLLATE_TEXT},
+  status VARCHAR(32) NOT NULL COLLATE {$COLLATE_TEXT},
+  properties LONGTEXT NOT NULL COLLATE {$COLLATE_TEXT},
+  dateCreated INT UNSIGNED NOT NULL,
+  dateModified INT UNSIGNED NOT NULL
+) ENGINE=InnoDB, COLLATE {$COLLATE_TEXT};
diff --git a/resources/sql/autopatches/20190116.contact.02.xaction.sql b/resources/sql/autopatches/20190116.contact.02.xaction.sql
new file mode 100644
--- /dev/null
+++ b/resources/sql/autopatches/20190116.contact.02.xaction.sql
@@ -0,0 +1,19 @@
+CREATE TABLE {$NAMESPACE}_auth.auth_contactnumbertransaction (
+  id INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
+  phid VARBINARY(64) NOT NULL,
+  authorPHID VARBINARY(64) NOT NULL,
+  objectPHID VARBINARY(64) NOT NULL,
+  viewPolicy VARBINARY(64) NOT NULL,
+  editPolicy VARBINARY(64) NOT NULL,
+  commentPHID VARBINARY(64) DEFAULT NULL,
+  commentVersion INT UNSIGNED NOT NULL,
+  transactionType VARCHAR(32) NOT NULL,
+  oldValue LONGTEXT NOT NULL,
+  newValue LONGTEXT NOT NULL,
+  contentSource LONGTEXT NOT NULL,
+  metadata LONGTEXT NOT NULL,
+  dateCreated INT UNSIGNED NOT NULL,
+  dateModified INT UNSIGNED NOT NULL,
+  UNIQUE KEY `key_phid` (`phid`),
+  KEY `key_object` (`objectPHID`)
+) ENGINE=InnoDB DEFAULT CHARSET={$CHARSET} COLLATE {$COLLATE_TEXT};
diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -2201,6 +2201,18 @@
     'PhabricatorAuthConduitAPIMethod' => 'applications/auth/conduit/PhabricatorAuthConduitAPIMethod.php',
     'PhabricatorAuthConduitTokenRevoker' => 'applications/auth/revoker/PhabricatorAuthConduitTokenRevoker.php',
     'PhabricatorAuthConfirmLinkController' => 'applications/auth/controller/PhabricatorAuthConfirmLinkController.php',
+    'PhabricatorAuthContactNumber' => 'applications/auth/storage/PhabricatorAuthContactNumber.php',
+    'PhabricatorAuthContactNumberController' => 'applications/auth/controller/contact/PhabricatorAuthContactNumberController.php',
+    'PhabricatorAuthContactNumberEditController' => 'applications/auth/controller/contact/PhabricatorAuthContactNumberEditController.php',
+    'PhabricatorAuthContactNumberEditEngine' => 'applications/auth/editor/PhabricatorAuthContactNumberEditEngine.php',
+    'PhabricatorAuthContactNumberEditor' => 'applications/auth/editor/PhabricatorAuthContactNumberEditor.php',
+    'PhabricatorAuthContactNumberNumberTransaction' => 'applications/auth/xaction/PhabricatorAuthContactNumberNumberTransaction.php',
+    'PhabricatorAuthContactNumberPHIDType' => 'applications/auth/phid/PhabricatorAuthContactNumberPHIDType.php',
+    'PhabricatorAuthContactNumberQuery' => 'applications/auth/query/PhabricatorAuthContactNumberQuery.php',
+    'PhabricatorAuthContactNumberTransaction' => 'applications/auth/storage/PhabricatorAuthContactNumberTransaction.php',
+    'PhabricatorAuthContactNumberTransactionQuery' => 'applications/auth/query/PhabricatorAuthContactNumberTransactionQuery.php',
+    'PhabricatorAuthContactNumberTransactionType' => 'applications/auth/xaction/PhabricatorAuthContactNumberTransactionType.php',
+    'PhabricatorAuthContactNumberViewController' => 'applications/auth/controller/contact/PhabricatorAuthContactNumberViewController.php',
     'PhabricatorAuthController' => 'applications/auth/controller/PhabricatorAuthController.php',
     'PhabricatorAuthDAO' => 'applications/auth/storage/PhabricatorAuthDAO.php',
     'PhabricatorAuthDisableController' => 'applications/auth/controller/config/PhabricatorAuthDisableController.php',
@@ -2723,6 +2735,7 @@
     'PhabricatorConpherenceWidgetVisibleSetting' => 'applications/settings/setting/PhabricatorConpherenceWidgetVisibleSetting.php',
     'PhabricatorConsoleApplication' => 'applications/console/application/PhabricatorConsoleApplication.php',
     'PhabricatorConsoleContentSource' => 'infrastructure/contentsource/PhabricatorConsoleContentSource.php',
+    'PhabricatorContactNumbersSettingsPanel' => 'applications/settings/panel/PhabricatorContactNumbersSettingsPanel.php',
     'PhabricatorContentSource' => 'infrastructure/contentsource/PhabricatorContentSource.php',
     'PhabricatorContentSourceModule' => 'infrastructure/contentsource/PhabricatorContentSourceModule.php',
     'PhabricatorContentSourceView' => 'infrastructure/contentsource/PhabricatorContentSourceView.php',
@@ -3855,6 +3868,7 @@
     'PhabricatorPholioConfigOptions' => 'applications/pholio/config/PhabricatorPholioConfigOptions.php',
     'PhabricatorPholioMockTestDataGenerator' => 'applications/pholio/lipsum/PhabricatorPholioMockTestDataGenerator.php',
     'PhabricatorPhoneNumber' => 'applications/metamta/message/PhabricatorPhoneNumber.php',
+    'PhabricatorPhoneNumberTestCase' => 'applications/metamta/message/__tests__/PhabricatorPhoneNumberTestCase.php',
     'PhabricatorPhortuneApplication' => 'applications/phortune/application/PhabricatorPhortuneApplication.php',
     'PhabricatorPhortuneContentSource' => 'applications/phortune/contentsource/PhabricatorPhortuneContentSource.php',
     'PhabricatorPhortuneManagementInvoiceWorkflow' => 'applications/phortune/management/PhabricatorPhortuneManagementInvoiceWorkflow.php',
@@ -7869,6 +7883,23 @@
     'PhabricatorAuthConduitAPIMethod' => 'ConduitAPIMethod',
     'PhabricatorAuthConduitTokenRevoker' => 'PhabricatorAuthRevoker',
     'PhabricatorAuthConfirmLinkController' => 'PhabricatorAuthController',
+    'PhabricatorAuthContactNumber' => array(
+      'PhabricatorAuthDAO',
+      'PhabricatorApplicationTransactionInterface',
+      'PhabricatorPolicyInterface',
+      'PhabricatorDestructibleInterface',
+    ),
+    'PhabricatorAuthContactNumberController' => 'PhabricatorAuthController',
+    'PhabricatorAuthContactNumberEditController' => 'PhabricatorAuthContactNumberController',
+    'PhabricatorAuthContactNumberEditEngine' => 'PhabricatorEditEngine',
+    'PhabricatorAuthContactNumberEditor' => 'PhabricatorApplicationTransactionEditor',
+    'PhabricatorAuthContactNumberNumberTransaction' => 'PhabricatorAuthContactNumberTransactionType',
+    'PhabricatorAuthContactNumberPHIDType' => 'PhabricatorPHIDType',
+    'PhabricatorAuthContactNumberQuery' => 'PhabricatorCursorPagedPolicyAwareQuery',
+    'PhabricatorAuthContactNumberTransaction' => 'PhabricatorModularTransaction',
+    'PhabricatorAuthContactNumberTransactionQuery' => 'PhabricatorApplicationTransactionQuery',
+    'PhabricatorAuthContactNumberTransactionType' => 'PhabricatorModularTransactionType',
+    'PhabricatorAuthContactNumberViewController' => 'PhabricatorAuthContactNumberController',
     'PhabricatorAuthController' => 'PhabricatorController',
     'PhabricatorAuthDAO' => 'PhabricatorLiskDAO',
     'PhabricatorAuthDisableController' => 'PhabricatorAuthProviderConfigController',
@@ -8487,6 +8518,7 @@
     'PhabricatorConpherenceWidgetVisibleSetting' => 'PhabricatorInternalSetting',
     'PhabricatorConsoleApplication' => 'PhabricatorApplication',
     'PhabricatorConsoleContentSource' => 'PhabricatorContentSource',
+    'PhabricatorContactNumbersSettingsPanel' => 'PhabricatorSettingsPanel',
     'PhabricatorContentSource' => 'Phobject',
     'PhabricatorContentSourceModule' => 'PhabricatorConfigModule',
     'PhabricatorContentSourceView' => 'AphrontView',
@@ -9780,6 +9812,7 @@
     'PhabricatorPholioConfigOptions' => 'PhabricatorApplicationConfigOptions',
     'PhabricatorPholioMockTestDataGenerator' => 'PhabricatorTestDataGenerator',
     'PhabricatorPhoneNumber' => 'Phobject',
+    'PhabricatorPhoneNumberTestCase' => 'PhabricatorTestCase',
     'PhabricatorPhortuneApplication' => 'PhabricatorApplication',
     'PhabricatorPhortuneContentSource' => 'PhabricatorContentSource',
     'PhabricatorPhortuneManagementInvoiceWorkflow' => 'PhabricatorPhortuneManagementWorkflow',
diff --git a/src/applications/auth/application/PhabricatorAuthApplication.php b/src/applications/auth/application/PhabricatorAuthApplication.php
--- a/src/applications/auth/application/PhabricatorAuthApplication.php
+++ b/src/applications/auth/application/PhabricatorAuthApplication.php
@@ -94,6 +94,13 @@
           '(?P<id>[1-9]\d*)/' =>
             'PhabricatorAuthFactorProviderViewController',
         ),
+
+        'contact/' => array(
+          $this->getEditRoutePattern('edit/') =>
+            'PhabricatorAuthContactNumberEditController',
+          '(?P<id>[1-9]\d*)/' =>
+            'PhabricatorAuthContactNumberViewController',
+        ),
       ),
 
       '/oauth/(?P<provider>\w+)/login/'
diff --git a/src/applications/auth/controller/contact/PhabricatorAuthContactNumberController.php b/src/applications/auth/controller/contact/PhabricatorAuthContactNumberController.php
new file mode 100644
--- /dev/null
+++ b/src/applications/auth/controller/contact/PhabricatorAuthContactNumberController.php
@@ -0,0 +1,16 @@
+<?php
+
+abstract class PhabricatorAuthContactNumberController
+  extends PhabricatorAuthController {
+
+  protected function buildApplicationCrumbs() {
+    $crumbs = parent::buildApplicationCrumbs();
+
+    $crumbs->addTextCrumb(
+      pht('Contact Numbers'),
+      pht('/settings/panel/contact/'));
+
+    return $crumbs;
+  }
+
+}
diff --git a/src/applications/auth/controller/contact/PhabricatorAuthContactNumberEditController.php b/src/applications/auth/controller/contact/PhabricatorAuthContactNumberEditController.php
new file mode 100644
--- /dev/null
+++ b/src/applications/auth/controller/contact/PhabricatorAuthContactNumberEditController.php
@@ -0,0 +1,12 @@
+<?php
+
+final class PhabricatorAuthContactNumberEditController
+  extends PhabricatorAuthContactNumberController {
+
+  public function handleRequest(AphrontRequest $request) {
+    return id(new PhabricatorAuthContactNumberEditEngine())
+      ->setController($this)
+      ->buildResponse();
+  }
+
+}
diff --git a/src/applications/auth/controller/contact/PhabricatorAuthContactNumberViewController.php b/src/applications/auth/controller/contact/PhabricatorAuthContactNumberViewController.php
new file mode 100644
--- /dev/null
+++ b/src/applications/auth/controller/contact/PhabricatorAuthContactNumberViewController.php
@@ -0,0 +1,98 @@
+<?php
+
+final class PhabricatorAuthContactNumberViewController
+  extends PhabricatorAuthContactNumberController {
+
+  public function handleRequest(AphrontRequest $request) {
+    $viewer = $this->getViewer();
+
+    $number = id(new PhabricatorAuthContactNumberQuery())
+      ->setViewer($viewer)
+      ->withIDs(array($request->getURIData('id')))
+      ->executeOne();
+    if (!$number) {
+      return new Aphront404Response();
+    }
+
+    $crumbs = $this->buildApplicationCrumbs()
+      ->addTextCrumb($number->getObjectName())
+      ->setBorder(true);
+
+    $header = $this->buildHeaderView($number);
+    $properties = $this->buildPropertiesView($number);
+    $curtain = $this->buildCurtain($number);
+
+    $timeline = $this->buildTransactionTimeline(
+      $number,
+      new PhabricatorAuthContactNumberTransactionQuery());
+    $timeline->setShouldTerminate(true);
+
+    $view = id(new PHUITwoColumnView())
+      ->setHeader($header)
+      ->setCurtain($curtain)
+      ->setMainColumn(
+        array(
+          $timeline,
+        ))
+      ->addPropertySection(pht('Details'), $properties);
+
+    return $this->newPage()
+      ->setTitle($number->getDisplayName())
+      ->setCrumbs($crumbs)
+      ->setPageObjectPHIDs(
+        array(
+          $number->getPHID(),
+        ))
+      ->appendChild($view);
+  }
+
+  private function buildHeaderView(PhabricatorAuthContactNumber $number) {
+    $viewer = $this->getViewer();
+
+    $view = id(new PHUIHeaderView())
+      ->setViewer($viewer)
+      ->setHeader($number->getObjectName())
+      ->setPolicyObject($number);
+
+    return $view;
+  }
+
+  private function buildPropertiesView(
+    PhabricatorAuthContactNumber $number) {
+    $viewer = $this->getViewer();
+
+    $view = id(new PHUIPropertyListView())
+      ->setViewer($viewer);
+
+    $view->addProperty(
+      pht('Owner'),
+      $viewer->renderHandle($number->getObjectPHID()));
+
+    $view->addProperty(pht('Contact Number'), $number->getDisplayName());
+
+    return $view;
+  }
+
+  private function buildCurtain(PhabricatorAuthContactNumber $number) {
+    $viewer = $this->getViewer();
+    $id = $number->getID();
+
+    $can_edit = PhabricatorPolicyFilter::hasCapability(
+      $viewer,
+      $number,
+      PhabricatorPolicyCapability::CAN_EDIT);
+
+    $curtain = $this->newCurtainView($number);
+
+    $curtain->addAction(
+      id(new PhabricatorActionView())
+        ->setName(pht('Edit Contact Number'))
+        ->setIcon('fa-pencil')
+        ->setHref($this->getApplicationURI("contact/edit/{$id}/"))
+        ->setDisabled(!$can_edit)
+        ->setWorkflow(!$can_edit));
+
+    return $curtain;
+  }
+
+}
diff --git a/src/applications/auth/editor/PhabricatorAuthContactNumberEditEngine.php b/src/applications/auth/editor/PhabricatorAuthContactNumberEditEngine.php
new file mode 100644
--- /dev/null
+++ b/src/applications/auth/editor/PhabricatorAuthContactNumberEditEngine.php
@@ -0,0 +1,86 @@
+<?php
+
+final class PhabricatorAuthContactNumberEditEngine
+  extends PhabricatorEditEngine {
+
+  const ENGINECONST = 'auth.contact';
+
+  public function isEngineConfigurable() {
+    return false;
+  }
+
+  public function getEngineName() {
+    return pht('Contact Numbers');
+  }
+
+  public function getSummaryHeader() {
+    return pht('Edit Contact Numbers');
+  }
+
+  public function getSummaryText() {
+    return pht('This engine is used to edit contact numbers.');
+  }
+
+  public function getEngineApplicationClass() {
+    return 'PhabricatorAuthApplication';
+  }
+
+  protected function newEditableObject() {
+    $viewer = $this->getViewer();
+    return PhabricatorAuthContactNumber::initializeNewContactNumber($viewer);
+  }
+
+  protected function newObjectQuery() {
+    return new PhabricatorAuthContactNumberQuery();
+  }
+
+  protected function getObjectCreateTitleText($object) {
+    return pht('Create Contact Number');
+  }
+
+  protected function getObjectCreateButtonText($object) {
+    return pht('Create Contact Number');
+  }
+
+  protected function getObjectEditTitleText($object) {
+    return pht('Edit Contact Number');
+  }
+
+  protected function getObjectEditShortText($object) {
+    return $object->getObjectName();
+  }
+
+  protected function getObjectCreateShortText() {
+    return pht('Create Contact Number');
+  }
+
+  protected function getObjectName() {
+    return pht('Contact Number');
+  }
+
+  protected function getEditorURI() {
+    return '/auth/contact/edit/';
+  }
+
+  protected function getObjectCreateCancelURI($object) {
+    return '/settings/panel/contact/';
+  }
+
+  protected function getObjectViewURI($object) {
+    return $object->getURI();
+  }
+
+  protected function buildCustomEditFields($object) {
+    return array(
+      id(new PhabricatorTextEditField())
+        ->setKey('contactNumber')
+        ->setTransactionType(
+          PhabricatorAuthContactNumberNumberTransaction::TRANSACTIONTYPE)
+        ->setLabel(pht('Contact Number'))
+        ->setDescription(pht('The contact number.'))
+        ->setValue($object->getContactNumber())
+        ->setIsRequired(true),
+    );
+  }
+
+}
diff --git a/src/applications/auth/editor/PhabricatorAuthContactNumberEditor.php b/src/applications/auth/editor/PhabricatorAuthContactNumberEditor.php
new file mode 100644
--- /dev/null
+++ b/src/applications/auth/editor/PhabricatorAuthContactNumberEditor.php
@@ -0,0 +1,38 @@
+<?php
+
+final class PhabricatorAuthContactNumberEditor
+  extends PhabricatorApplicationTransactionEditor {
+
+  public function getEditorApplicationClass() {
+    return 'PhabricatorAuthApplication';
+  }
+
+  public function getEditorObjectsDescription() {
+    return pht('Contact Numbers');
+  }
+
+  public function getCreateObjectTitle($author, $object) {
+    return pht('%s created this contact number.', $author);
+  }
+
+  public function getCreateObjectTitleForFeed($author, $object) {
+    return pht('%s created %s.', $author, $object);
+  }
+
+  protected function didCatchDuplicateKeyException(
+    PhabricatorLiskDAO $object,
+    array $xactions,
+    Exception $ex) {
+
+    $errors = array();
+    $errors[] = new PhabricatorApplicationTransactionValidationError(
+      PhabricatorAuthContactNumberNumberTransaction::TRANSACTIONTYPE,
+      pht('Duplicate'),
+      pht('This contact number is already in use.'),
+      null);
+
+    throw new PhabricatorApplicationTransactionValidationException($errors);
+  }
+
+
+}
diff --git a/src/applications/auth/phid/PhabricatorAuthContactNumberPHIDType.php b/src/applications/auth/phid/PhabricatorAuthContactNumberPHIDType.php
new file mode 100644
--- /dev/null
+++ b/src/applications/auth/phid/PhabricatorAuthContactNumberPHIDType.php
@@ -0,0 +1,38 @@
+<?php
+
+final class PhabricatorAuthContactNumberPHIDType
+  extends PhabricatorPHIDType {
+
+  const TYPECONST = 'CTNM';
+
+  public function getTypeName() {
+    return pht('Contact Number');
+  }
+
+  public function newObject() {
+    return new PhabricatorAuthContactNumber();
+  }
+
+  public function getPHIDTypeApplicationClass() {
+    return 'PhabricatorAuthApplication';
+  }
+
+  protected function buildQueryForObjects(
+    PhabricatorObjectQuery $query,
+    array $phids) {
+
+    return id(new PhabricatorAuthContactNumberQuery())
+      ->withPHIDs($phids);
+  }
+
+  public function loadHandles(
+    PhabricatorHandleQuery $query,
+    array $handles,
+    array $objects) {
+
+    foreach ($handles as $phid => $handle) {
+      $contact_number = $objects[$phid];
+    }
+  }
+
+}
diff --git a/src/applications/auth/query/PhabricatorAuthContactNumberQuery.php b/src/applications/auth/query/PhabricatorAuthContactNumberQuery.php
new file mode 100644
--- /dev/null
+++ b/src/applications/auth/query/PhabricatorAuthContactNumberQuery.php
@@ -0,0 +1,90 @@
+<?php
+
+final class PhabricatorAuthContactNumberQuery
+  extends PhabricatorCursorPagedPolicyAwareQuery {
+
+  private $ids;
+  private $phids;
+  private $objectPHIDs;
+  private $statuses;
+  private $contactNumbers;
+
+  public function withIDs(array $ids) {
+    $this->ids = $ids;
+    return $this;
+  }
+
+  public function withPHIDs(array $phids) {
+    $this->phids = $phids;
+    return $this;
+  }
+
+  public function withObjectPHIDs(array $object_phids) {
+    $this->objectPHIDs = $object_phids;
+    return $this;
+  }
+
+  public function withStatuses(array $statuses) {
+    $this->statuses = $statuses;
+    return $this;
+  }
+
+  public function withContactNumbers(array $contact_numbers) {
+    $this->contactNumbers = $contact_numbers;
+    return $this;
+  }
+
+  public function newResultObject() {
+    return new PhabricatorAuthContactNumber();
+  }
+
+  protected function loadPage() {
+    return $this->loadStandardPage($this->newResultObject());
+  }
+
+  protected function buildWhereClauseParts(AphrontDatabaseConnection $conn) {
+    $where = parent::buildWhereClauseParts($conn);
+
+    if ($this->ids !== null) {
+      $where[] = qsprintf(
+        $conn,
+        'id IN (%Ld)',
+        $this->ids);
+    }
+
+    if ($this->phids !== null) {
+      $where[] = qsprintf(
+        $conn,
+        'phid IN (%Ls)',
+        $this->phids);
+    }
+
+    if ($this->objectPHIDs !== null) {
+      $where[] = qsprintf(
+        $conn,
+        'objectPHID IN (%Ls)',
+        $this->objectPHIDs);
+    }
+
+    if ($this->statuses !== null) {
+      $where[] = qsprintf(
+        $conn,
+        'status IN (%Ls)',
+        $this->statuses);
+    }
+
+    if ($this->contactNumbers !== null) {
+      $where[] = qsprintf(
+        $conn,
+        'contactNumber IN (%Ls)',
+        $this->contactNumbers);
+    }
+
+    return $where;
+  }
+
+  public function getQueryApplicationClass() {
+    return 'PhabricatorAuthApplication';
+  }
+
+}
diff --git a/src/applications/auth/query/PhabricatorAuthContactNumberTransactionQuery.php b/src/applications/auth/query/PhabricatorAuthContactNumberTransactionQuery.php
new file mode 100644
--- /dev/null
+++ b/src/applications/auth/query/PhabricatorAuthContactNumberTransactionQuery.php
@@ -0,0 +1,10 @@
+<?php
+
+final class PhabricatorAuthContactNumberTransactionQuery
+  extends PhabricatorApplicationTransactionQuery {
+
+  public function getTemplateApplicationTransaction() {
+    return new PhabricatorAuthContactNumberTransaction();
+  }
+
+}
diff --git a/src/applications/auth/storage/PhabricatorAuthContactNumber.php b/src/applications/auth/storage/PhabricatorAuthContactNumber.php
new file mode 100644
--- /dev/null
+++ b/src/applications/auth/storage/PhabricatorAuthContactNumber.php
@@ -0,0 +1,117 @@
+<?php
+
+
+final class PhabricatorAuthContactNumber
+  extends PhabricatorAuthDAO
+  implements
+    PhabricatorApplicationTransactionInterface,
+    PhabricatorPolicyInterface,
+    PhabricatorDestructibleInterface {
+
+  protected $objectPHID;
+  protected $contactNumber;
+  protected $status;
+  protected $properties = array();
+
+  const STATUS_ACTIVE = 'active';
+  const STATUS_DISABLED = 'disabled';
+
+  protected function getConfiguration() {
+    return array(
+      self::CONFIG_SERIALIZATION => array(
+        'properties' => self::SERIALIZATION_JSON,
+      ),
+      self::CONFIG_AUX_PHID => true,
+      self::CONFIG_COLUMN_SCHEMA => array(
+        'contactNumber' => 'text255',
+        'status' => 'text32',
+      ),
+      self::CONFIG_KEY_SCHEMA => array(
+        'key_number' => array(
+          'columns' => array('contactNumber'),
+          'unique' => true,
+        ),
+      ),
+    ) + parent::getConfiguration();
+  }
+
+  public static function initializeNewContactNumber($object) {
+    return id(new self())
+      ->setStatus(self::STATUS_ACTIVE)
+      ->setObjectPHID($object->getPHID());
+  }
+
+  public function getPHIDType() {
+    return PhabricatorAuthContactNumberPHIDType::TYPECONST;
+  }
+
+  public function getURI() {
+    return urisprintf('/auth/contact/%s/', $this->getID());
+  }
+
+  public function getObjectName() {
+    return pht('Contact Number %d', $this->getID());
+  }
+
+  public function getDisplayName() {
+    return $this->getContactNumber();
+  }
+
+  public function isDisabled() {
+    return ($this->getStatus() === self::STATUS_DISABLED);
+  }
+
+  public function newIconView() {
+    if ($this->isDisabled()) {
+      return id(new PHUIIconView())
+        ->setIcon('fa-ban', 'grey')
+        ->setTooltip(pht('Disabled'));
+    }
+
+    return id(new PHUIIconView())
+      ->setIcon('fa-mobile', 'green')
+      ->setTooltip(pht('Active Phone Number'));
+  }
+
+
+/* -(  PhabricatorPolicyInterface  )----------------------------------------- */
+
+
+  public function getCapabilities() {
+    return array(
+      PhabricatorPolicyCapability::CAN_VIEW,
+      PhabricatorPolicyCapability::CAN_EDIT,
+    );
+  }
+
+  public function getPolicy($capability) {
+    return $this->getObjectPHID();
+  }
+
+  public function hasAutomaticCapability($capability, PhabricatorUser $viewer) {
+    return false;
+  }
+
+
+/* -(  PhabricatorDestructibleInterface  )----------------------------------- */
+
+
+  public function destroyObjectPermanently(
+    PhabricatorDestructionEngine $engine) {
+    $this->delete();
+  }
+
+
+/* -(  PhabricatorApplicationTransactionInterface  )------------------------- */
+
+
+  public function getApplicationTransactionEditor() {
+    return new PhabricatorAuthContactNumberEditor();
+  }
+
+  public function getApplicationTransactionTemplate() {
+    return new PhabricatorAuthContactNumberTransaction();
+  }
+
+
+}
diff --git a/src/applications/auth/storage/PhabricatorAuthContactNumberTransaction.php b/src/applications/auth/storage/PhabricatorAuthContactNumberTransaction.php
new file mode 100644
--- /dev/null
+++ b/src/applications/auth/storage/PhabricatorAuthContactNumberTransaction.php
@@ -0,0 +1,18 @@
+<?php
+
+final class PhabricatorAuthContactNumberTransaction
+  extends PhabricatorModularTransaction {
+
+  public function getApplicationName() {
+    return 'auth';
+  }
+
+  public function getApplicationTransactionType() {
+    return PhabricatorAuthContactNumberPHIDType::TYPECONST;
+  }
+
+  public function getBaseTransactionClass() {
+    return 'PhabricatorAuthContactNumberTransactionType';
+  }
+
+}
diff --git a/src/applications/auth/xaction/PhabricatorAuthContactNumberNumberTransaction.php b/src/applications/auth/xaction/PhabricatorAuthContactNumberNumberTransaction.php
new file mode 100644
--- /dev/null
+++ b/src/applications/auth/xaction/PhabricatorAuthContactNumberNumberTransaction.php
@@ -0,0 +1,87 @@
+<?php
+
+final class PhabricatorAuthContactNumberNumberTransaction
+  extends PhabricatorAuthContactNumberTransactionType {
+
+  const TRANSACTIONTYPE = 'number';
+
+  public function generateOldValue($object) {
+    return $object->getContactNumber();
+  }
+
+  public function generateNewValue($object, $value) {
+    $number = new PhabricatorPhoneNumber($value);
+    return $number->toE164();
+  }
+
+  public function applyInternalEffects($object, $value) {
+    $object->setContactNumber($value);
+  }
+
+  public function getTitle() {
+    $old = $this->getOldValue();
+    $new = $this->getNewValue();
+
+    return pht(
+      '%s changed this contact number from %s to %s.',
+      $this->renderAuthor(),
+      $this->renderOldValue(),
+      $this->renderNewValue());
+  }
+
+  public function validateTransactions($object, array $xactions) {
+    $errors = array();
+
+    $current_value = $object->getContactNumber();
+    if ($this->isEmptyTextTransaction($current_value, $xactions)) {
+      $errors[] = $this->newRequiredError(
+        pht('Contact numbers must have a contact number.'));
+      return $errors;
+    }
+
+    $max_length = $object->getColumnMaximumByteLength('contactNumber');
+    foreach ($xactions as $xaction) {
+      $new_value = $xaction->getNewValue();
+      $new_length = strlen($new_value);
+      if ($new_length > $max_length) {
+        $errors[] = $this->newInvalidError(
+          pht(
+            'Contact numbers can not be longer than %s characters.',
+            new PhutilNumber($max_length)),
+          $xaction);
+        continue;
+      }
+
+      try {
+        new PhabricatorPhoneNumber($new_value);
+      } catch (Exception $ex) {
+        $errors[] = $this->newInvalidError(
+          pht(
+            'Contact number is invalid: %s',
+            $ex->getMessage()),
+          $xaction);
+        continue;
+      }
+
+      $normal_value = $this->generateNewValue($object, $new_value);
+
+      $other = id(new PhabricatorAuthContactNumberQuery())
+        ->setViewer(PhabricatorUser::getOmnipotentUser())
+        ->withContactNumbers(array($normal_value))
+        ->executeOne();
+
+      if ($other) {
+        if ($other->getID() !== $object->getID()) {
+          $errors[] = $this->newInvalidError(
+            pht('Contact number is already in use.'),
+            $xaction);
+          continue;
+        }
+      }
+
+    }
+
+    return $errors;
+  }
+
+}
diff --git a/src/applications/auth/xaction/PhabricatorAuthContactNumberTransactionType.php b/src/applications/auth/xaction/PhabricatorAuthContactNumberTransactionType.php
new file mode 100644
--- /dev/null
+++ b/src/applications/auth/xaction/PhabricatorAuthContactNumberTransactionType.php
@@ -0,0 +1,4 @@
+<?php
+
+abstract class PhabricatorAuthContactNumberTransactionType
+  extends PhabricatorModularTransactionType {}
diff --git a/src/applications/metamta/message/PhabricatorPhoneNumber.php b/src/applications/metamta/message/PhabricatorPhoneNumber.php
--- a/src/applications/metamta/message/PhabricatorPhoneNumber.php
+++ b/src/applications/metamta/message/PhabricatorPhoneNumber.php
@@ -8,13 +8,23 @@
   public function __construct($raw_number) {
     $number = preg_replace('/[^\d]+/', '', $raw_number);
 
-    if (!preg_match('/^[1-9]\d{1,14}\z/', $number)) {
+    if (!preg_match('/^[1-9]\d{9,14}\z/', $number)) {
       throw new Exception(
         pht(
-          'Phone number ("%s") is not in a recognized format.',
+          'Phone number ("%s") is not in a recognized format: expected a '.
+          'US number like "(555) 555-5555", or an international number '.
+          'like "+55 5555 555555".',
           $raw_number));
     }
 
+    // If the number didn't start with "+" and has has 10 digits, assume it is
+    // a US number with no country code prefix, like "(555) 555-5555".
+    if (!preg_match('/^+/', $raw_number)) {
+      if (strlen($number) === 10) {
+        $number = '1'.$number;
+      }
+    }
+
     $this->number = $number;
   }
 
diff --git a/src/applications/metamta/message/__tests__/PhabricatorPhoneNumberTestCase.php b/src/applications/metamta/message/__tests__/PhabricatorPhoneNumberTestCase.php
new file mode 100644
--- /dev/null
+++ b/src/applications/metamta/message/__tests__/PhabricatorPhoneNumberTestCase.php
@@ -0,0 +1,37 @@
+<?php
+
+final class PhabricatorPhoneNumberTestCase
+  extends PhabricatorTestCase {
+
+  public function testNumberNormalization() {
+    $map = array(
+      '+15555555555' => '+15555555555',
+      '+1 (555) 555-5555' => '+15555555555',
+      '(555) 555-5555' => '+15555555555',
+
+      '' => false,
+      '1-800-CALL-SAUL' => false,
+    );
+
+    foreach ($map as $input => $expect) {
+      $caught = null;
+      try {
+        $actual = id(new PhabricatorPhoneNumber($input))
+          ->toE164();
+      } catch (Exception $ex) {
+        $caught = $ex;
+      }
+
+      $this->assertEqual(
+        (bool)$caught,
+        ($expect === false),
+        pht('Exception raised by: %s', $input));
+
+      if ($expect !== false) {
+        $this->assertEqual($expect, $actual, pht('E164 of: %s', $input));
+      }
+    }
+
+  }
+
+}
diff --git a/src/applications/search/view/PhabricatorSearchResultView.php b/src/applications/search/view/PhabricatorSearchResultView.php
--- a/src/applications/search/view/PhabricatorSearchResultView.php
+++ b/src/applications/search/view/PhabricatorSearchResultView.php
@@ -126,7 +126,7 @@
     }
 
     // Go through the string one display glyph at a time. If a glyph starts
-    // on a highlighted byte position, turn on highlighting for the nubmer
+    // on a highlighted byte position, turn on highlighting for the number
     // of matching bytes. If a query searches for "e" and the document contains
     // an "e" followed by a bunch of combining marks, this will correctly
     // highlight the entire glyph.
diff --git a/src/applications/settings/panel/PhabricatorContactNumbersSettingsPanel.php b/src/applications/settings/panel/PhabricatorContactNumbersSettingsPanel.php
new file mode 100644
--- /dev/null
+++ b/src/applications/settings/panel/PhabricatorContactNumbersSettingsPanel.php
@@ -0,0 +1,69 @@
+<?php
+
+final class PhabricatorContactNumbersSettingsPanel
+  extends PhabricatorSettingsPanel {
+
+  public function getPanelKey() {
+    return 'contact';
+  }
+
+  public function getPanelName() {
+    return pht('Contact Numbers');
+  }
+
+  public function getPanelGroupKey() {
+    return PhabricatorSettingsAuthenticationPanelGroup::PANELGROUPKEY;
+  }
+
+  public function processRequest(AphrontRequest $request) {
+    $user = $this->getUser();
+    $viewer = $request->getUser();
+
+    $numbers = id(new PhabricatorAuthContactNumberQuery())
+      ->setViewer($viewer)
+      ->withObjectPHIDs(array($user->getPHID()))
+      ->execute();
+
+    $rows = array();
+    foreach ($numbers as $number) {
+      $rows[] = array(
+        $number->newIconView(),
+        phutil_tag(
+          'a',
+          array(
+            'href' => $number->getURI(),
+          ),
+          $number->getDisplayName()),
+        phabricator_datetime($number->getDateCreated(), $viewer),
+      );
+    }
+
+    $table = id(new AphrontTableView($rows))
+      ->setNoDataString(
+        pht("You haven't added any contact numbers to your account."))
+      ->setHeaders(
+        array(
+          null,
+          pht('Number'),
+          pht('Created'),
+        ))
+      ->setColumnClasses(
+        array(
+          null,
+          'wide pri',
+          'right',
+        ));
+
+    $buttons = array();
+
+    $buttons[] = id(new PHUIButtonView())
+      ->setTag('a')
+      ->setIcon('fa-plus')
+      ->setText(pht('Add Contact Number'))
+      ->setHref('/auth/contact/edit/')
+      ->setColor(PHUIButtonView::GREY);
+
+    return $this->newBox(pht('Contact Numbers'), $table, $buttons);
+  }
+
+}