diff --git a/.travis.yml b/.travis.yml
index f9ab374..f36962f 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -50,6 +50,8 @@ install:
   - test ${DRUPAL_VERSION} -eq 8.5.x || (cd drupal && composer run-script drupal-phpunit-upgrade && cd -)
   - mv /tmp/$MODULE_NAME drupal/modules/
   - cd drupal
+  - composer require drupal/sms
+  - composer require drupal/dynamic_entity_reference
   # Install the message module from github
   # Use working branch until PRs are merged in main repo.
   - cd modules && git clone -b 8.x-1.x https://github.com/Gizra/message.git && cd -
diff --git a/composer.json b/composer.json
index 8b56a61..dc00c75 100644
--- a/composer.json
+++ b/composer.json
@@ -10,7 +10,10 @@
         "source": "https://cgit.drupalcode.org/message_notify"
     },
     "require": {
-      "drupal/message": "~8.1.0"
+        "drupal/message": "~8.1.0"
+    },
+    "suggest": {
+        "drupal/sms": "Allow message_notify_sms to send SMS."
     },
     "minimum-stability": "dev"
 }
diff --git a/modules/message_notify_sms/README.md b/modules/message_notify_sms/README.md
new file mode 100644
index 0000000..e778761
--- /dev/null
+++ b/modules/message_notify_sms/README.md
@@ -0,0 +1,19 @@
+# Message Notify SMS
+
+Support sending of notifications over SMS
+
+## Requirements
+
+- [`message_notify`](https://www.drupal.org/project/message_notify)
+- [`sms`](https://www.drupal.org/project/smsframework)
+
+## Installation
+
+- via admin: Go to `/admin/modules` and enable the module.
+- via Drush: `drush en -y message_notify_sms`
+
+## Configuration
+
+- Go to `/admin/config/message/message-subscribe`
+- Under "Default message notifiers", include `SMS` in your selection.
+- Click "Save configuration".
diff --git a/modules/message_notify_sms/config/install/core.entity_view_mode.message.sms_message.yml b/modules/message_notify_sms/config/install/core.entity_view_mode.message.sms_message.yml
new file mode 100644
index 0000000..b6a9d6d
--- /dev/null
+++ b/modules/message_notify_sms/config/install/core.entity_view_mode.message.sms_message.yml
@@ -0,0 +1,9 @@
+langcode: en
+status: true
+dependencies:
+  module:
+    - message
+id: message.sms_message
+label: 'Notify - SMS message'
+targetEntityType: message
+cache: true
diff --git a/modules/message_notify_sms/message_notify_sms.info.yml b/modules/message_notify_sms/message_notify_sms.info.yml
new file mode 100644
index 0000000..b03179e
--- /dev/null
+++ b/modules/message_notify_sms/message_notify_sms.info.yml
@@ -0,0 +1,8 @@
+name: 'Message Notify SMS'
+type: module
+package: Message
+description: 'Plugin for Message Notify to send SMS notifications.'
+core: 8.x
+dependencies:
+  - message_notify
+  - sms
diff --git a/modules/message_notify_sms/src/Plugin/Notifier/Sms.php b/modules/message_notify_sms/src/Plugin/Notifier/Sms.php
new file mode 100644
index 0000000..5f61a6c
--- /dev/null
+++ b/modules/message_notify_sms/src/Plugin/Notifier/Sms.php
@@ -0,0 +1,177 @@
+<?php
+
+namespace Drupal\message_notify_sms\Plugin\Notifier;
+
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Entity\EntityTypeManagerInterface;
+use Drupal\Core\Logger\LoggerChannelInterface;
+use Drupal\Core\Render\RendererInterface;
+use Drupal\message\MessageInterface;
+use Drupal\message_notify\Plugin\Notifier\MessageNotifierBase;
+use Drupal\sms\Direction;
+use Drupal\sms\Message\SmsMessage;
+use Drupal\sms\Provider\PhoneNumberProviderInterface;
+use Drupal\sms\Provider\SmsProviderInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * SMS notifier.
+ *
+ * @Notifier(
+ *   id = "sms",
+ *   title = @Translation("SMS"),
+ *   description = @Translation("Send messages via sms"),
+ *   viewModes = {
+ *     "sms_message"
+ *   }
+ * )
+ */
+class Sms extends MessageNotifierBase {
+
+  /**
+   * The SMS provider for entities.
+   *
+   * @var \Drupal\sms\Provider\PhoneNumberProviderInterface
+   */
+  protected $phoneNumberProvider;
+
+  /**
+   * The SMS provider for raw phone numbers.
+   *
+   * @var \Drupal\sms\Provider\SmsProviderInterface
+   */
+  protected $smsProvider;
+
+  /**
+   * Constructs the plugin.
+   *
+   * @param array $configuration
+   *   A configuration array containing information about the plugin instance.
+   * @param string $plugin_id
+   *   The plugin_id for the plugin instance.
+   * @param mixed $plugin_definition
+   *   The plugin implementation definition.
+   * @param \Drupal\Core\Logger\LoggerChannelInterface $logger
+   *   The message_notify_sms logger channel.
+   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
+   *   The entity type manager service.
+   * @param \Drupal\Core\Render\RendererInterface $renderer
+   *   The rendering service.
+   * @param \Drupal\message\MessageInterface $message
+   *   (optional) The message entity. This is required when sending or
+   *   delivering a notification. If not passed to the constructor, use
+   *   ::setMessage().
+   * @param \Drupal\sms\Provider\PhoneNumberProviderInterface $phone_number_provider
+   *   The sms provider (for entities).
+   * @param \Drupal\sms\Provider\SmsProviderInterface $sms_provider
+   *   The sms provider (for phone numbers).
+   */
+  public function __construct(array $configuration, $plugin_id, $plugin_definition, LoggerChannelInterface $logger, EntityTypeManagerInterface $entity_type_manager, RendererInterface $renderer, MessageInterface $message = NULL, PhoneNumberProviderInterface $phone_number_provider, SmsProviderInterface $sms_provider) {
+    // Set configuration defaults.
+    $configuration = $configuration + ['phone_number' => FALSE];
+
+    parent::__construct($configuration, $plugin_id, $plugin_definition, $logger, $entity_type_manager, $renderer, $message);
+
+    $this->phoneNumberProvider = $phone_number_provider;
+    $this->smsProvider = $sms_provider;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition, MessageInterface $message = NULL) {
+    return new static(
+      $configuration,
+      $plugin_id,
+      $plugin_definition,
+      $container->get('logger.channel.message_notify'),
+      $container->get('entity_type.manager'),
+      $container->get('renderer'),
+      $message,
+      $container->get('sms.phone_number'),
+      $container->get('sms.provider')
+    );
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function deliver(array $output = []) {
+    $message = trim(strip_tags($output['sms_message']));
+
+    if ($message === '') {
+      $this->logger->warning('Failed to send SMS. Message empty.', []);
+      return FALSE;
+    }
+
+    try {
+      $phone_number = $this->configuration['phone_number'];
+
+      if ($phone_number) {
+        $this->sendToNumber($message, $phone_number);
+
+        $this->logger->info('Queued SMS for {phone_number}.', [
+          'phone_number' => $phone_number,
+        ]);
+      }
+      else {
+        $user = $this->message->getOwner();
+        $this->sendToEntity($message, $user);
+
+        $this->logger->info('Queued SMS for {name} (uid: {id}).', [
+          'id' => $user->id(),
+          'name' => $user->getAccountName(),
+        ]);
+      }
+
+      return TRUE;
+    }
+    catch (\Exception $e) {
+      $this->logger->error('Failed to send SMS.', [
+        'exception' => $e,
+      ]);
+      return FALSE;
+    }
+  }
+
+  /**
+   * Send message to a phone number.
+   *
+   * @param string $message
+   *   The rendered message.
+   * @param string $number
+   *   The recepient's phone number.
+   *
+   * @throws \Drupal\sms\Exception\SmsDirectionException
+   *   Thrown if no direction is set for the message.
+   * @throws \Drupal\sms\Exception\RecipientRouteException
+   *   Thrown if no gateway could be determined for the message.
+   */
+  protected function sendToNumber($message, $number) {
+    $sms_message = (new SmsMessage())
+      ->setMessage($message)
+      ->addRecipient($number)
+      ->setDirection(Direction::OUTGOING);
+
+    $this->smsProvider->queue($sms_message);
+  }
+
+  /**
+   * Sends message to entity's configured phone number.
+   *
+   * @param string $message
+   *   The rendered message.
+   * @param \Drupal\Core\Entity\EntityInterface $entity
+   *   The receiving entity.
+   *
+   * @throws \Drupal\sms\Exception\NoPhoneNumberException
+   *   Thrown if entity does not have a phone number.
+   */
+  protected function sendToEntity($message, EntityInterface $entity) {
+    $sms_message = (new SmsMessage())
+      ->setMessage($message);
+
+    $this->phoneNumberProvider->sendMessage($entity, $sms_message);
+  }
+
+}
diff --git a/modules/message_notify_sms/tests/src/Kernel/MessageNotifySmsTest.php b/modules/message_notify_sms/tests/src/Kernel/MessageNotifySmsTest.php
new file mode 100644
index 0000000..ad385bc
--- /dev/null
+++ b/modules/message_notify_sms/tests/src/Kernel/MessageNotifySmsTest.php
@@ -0,0 +1,221 @@
+<?php
+
+namespace Drupal\Tests\message_notify_sms\Kernel;
+
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\KernelTests\KernelTestBase;
+use Drupal\message\Entity\Message;
+use Drupal\message\Entity\MessageTemplate;
+use Drupal\user\Entity\User;
+
+/**
+ * Test the Message notifier plugins handling.
+ *
+ * @group message_notify
+ */
+class MessageNotifySmsTest extends KernelTestBase {
+
+  /**
+   * Testing message template.
+   *
+   * @var \Drupal\message\MessageTemplateInterface
+   */
+  protected $messageTemplate;
+
+  /**
+   * The message notification service.
+   *
+   * @var \Drupal\message_notify\MessageNotifier
+   */
+  protected $messageNotifier;
+
+  /**
+   * The sample message.
+   *
+   * @var string
+   */
+  protected $messageText = 'Hello, World!';
+
+  /**
+   * The sample number.
+   *
+   * @var string
+   */
+  protected $messageNumber = '18001234567';
+
+  /**
+   * {@inheritdoc}
+   */
+  public static $modules = [
+    'system',
+    'field',
+    'text',
+    'user',
+    'telephone',
+    'dynamic_entity_reference',
+    'sms',
+    'message',
+    'message_notify',
+    'message_notify_sms',
+    'message_notify_sms_test',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setUp() {
+    parent::setUp();
+
+    $this->installSchema('system', ['sequences']);
+    $this->installEntitySchema('user');
+    $this->installEntitySchema('message');
+    $this->installEntitySchema('phone_number_settings');
+    $this->installEntitySchema('sms_phone_number_verification');
+    $this->installEntitySchema('sms_report');
+    $this->installEntitySchema('sms_gateway');
+    $this->installEntitySchema('sms');
+    $this->installEntitySchema('sms_result');
+    $this->installConfig([
+      'sms',
+      'message',
+      'message_notify',
+      'message_notify_sms',
+      'message_notify_sms_test',
+    ]);
+
+    $this->messageTemplate = MessageTemplate::load('message_notify_sms_test');
+
+    $this->messageNotifier = $this->container->get('message_notify.sender');
+  }
+
+  /**
+   * Tests notifier sending a message to an entity.
+   */
+  public function testSendEntity() {
+    // Create an active user with a phone number.
+    $user = User::create([
+      'name' => $this->randomMachineName(),
+      'field_sms' => $this->messageNumber,
+      'status' => 1,
+    ]);
+
+    $user->save();
+
+    $this->verifyEntityPhoneNumber($user);
+
+    $message = $this->createEntityMessage($user);
+    $result = $this->messageNotifier->send($message, [], 'sms');
+
+    $this->assertTrue($result);
+  }
+
+  /**
+   * Tests notifier sending a message to an inactive entity.
+   */
+  public function testSendEntityInactive() {
+    // Create an active user with a phone number.
+    $user = User::create([
+      'name' => $this->randomMachineName(),
+      'field_sms' => $this->messageNumber,
+    ]);
+
+    $user->save();
+
+    $this->verifyEntityPhoneNumber($user);
+
+    $message = $this->createEntityMessage($user);
+    $result = $this->messageNotifier->send($message, [], 'sms');
+
+    $this->assertFalse($result);
+  }
+
+  /**
+   * Tests notifier sending a message to an entity with no phone number.
+   */
+  public function testSendEntityNoNumber() {
+    // Create an active user with a phone number.
+    $user = User::create([
+      'name' => $this->randomMachineName(),
+      'status' => 1,
+    ]);
+
+    $user->save();
+
+    $message = $this->createEntityMessage($user);
+    $result = $this->messageNotifier->send($message, [], 'sms');
+
+    $this->assertFalse($result);
+  }
+
+  /**
+   * Tests notifier sending a message to an unverified entity.
+   */
+  public function testSendEntityUnverified() {
+    // Create an active user with a phone number.
+    $user = User::create([
+      'name' => $this->randomMachineName(),
+      'field_sms' => $this->messageNumber,
+      'status' => 1,
+    ]);
+
+    $user->save();
+
+    $message = $this->createEntityMessage($user);
+    $result = $this->messageNotifier->send($message, [], 'sms');
+
+    $this->assertFalse($result);
+  }
+
+  /**
+   * Tests notifier sending a message to a number.
+   */
+  public function testSendNumber() {
+    $message = Message::create([
+      'template' => $this->messageTemplate->id(),
+      'message_notify_sms_test_text' => $this->messageText,
+    ]);
+
+    $result = $this->messageNotifier->send($message, ['phone_number' => $this->messageNumber], 'sms');
+
+    $this->assertTrue($result);
+  }
+
+  /**
+   * Creates a Message object owned by the supplied entity.
+   *
+   * @param \Drupal\Core\Entity\EntityInterface $entity
+   *   The entity that owns the message.
+   *
+   * @return \Drupal\message\MessageInterface
+   *   The message object.
+   */
+  protected function createEntityMessage(EntityInterface $entity) {
+    return Message::create([
+      'uid' => $entity->id(),
+      'template' => $this->messageTemplate->id(),
+      'message_notify_sms_test_text' => $this->messageText,
+    ]);
+  }
+
+  /**
+   * Verify an entity's phone number, if one exists.
+   *
+   * @param \Drupal\Core\Entity\EntityInterface $entity
+   *   The entity whose phone number to verify.
+   *
+   * @throws \Drupal\Component\Plugin\Exception\InvalidPluginDefinitionException
+   * @throws \Drupal\Component\Plugin\Exception\PluginNotFoundException
+   */
+  protected function verifyEntityPhoneNumber(EntityInterface $entity) {
+    $verifications = \Drupal::entityTypeManager()
+      ->getStorage('sms_phone_number_verification')
+      ->loadByProperties([
+        'entity__target_type' => $entity->getEntityTypeId(),
+        'entity__target_id' => $entity->id(),
+        'phone' => $entity->field_sms->value,
+      ]);
+    $verification = reset($verifications);
+    $verification->setStatus(TRUE)->save();
+  }
+
+}
diff --git a/modules/message_notify_sms/tests/src/Unit/Plugin/Notifier/SmsTest.php b/modules/message_notify_sms/tests/src/Unit/Plugin/Notifier/SmsTest.php
new file mode 100644
index 0000000..953f28a
--- /dev/null
+++ b/modules/message_notify_sms/tests/src/Unit/Plugin/Notifier/SmsTest.php
@@ -0,0 +1,415 @@
+<?php
+
+namespace Drupal\Tests\message_notify_sms\Unit\Plugin\Notifier;
+
+use Drupal\Component\Uuid\UuidInterface;
+use Drupal\Core\DependencyInjection\ContainerBuilder;
+use Drupal\sms\Exception\SmsDirectionException;
+use Drupal\sms\Exception\RecipientRouteException;
+use Drupal\sms\Provider\SmsProviderInterface;
+use Drupal\user\UserInterface;
+use Drupal\Core\Entity\EntityTypeManagerInterface;
+use Drupal\Core\Language\Language;
+use Drupal\Core\Logger\LoggerChannelInterface;
+use Drupal\Core\Render\RendererInterface;
+use Drupal\message\MessageInterface;
+use Drupal\message_notify_sms\Plugin\Notifier\Sms;
+use Drupal\sms\Exception\NoPhoneNumberException;
+use Drupal\sms\Provider\PhoneNumberProviderInterface;
+use Drupal\Tests\UnitTestCase;
+use Exception;
+use Prophecy\Argument;
+
+/**
+ * Unit tests for the SMS notifier.
+ *
+ * @coversDefaultClass \Drupal\message_notify_sms\Plugin\Notifier\Sms
+ *
+ * @group message_notify_sms
+ */
+class SmsTest extends UnitTestCase {
+
+  /**
+   * Mocked configuration for entity delivery.
+   *
+   * @var array
+   */
+  protected $entityConfiguration;
+
+  /**
+   * Mocked configuration for number delivery.
+   *
+   * @var array
+   */
+  protected $numberConfiguration;
+
+  /**
+   * Mocked plugin id.
+   *
+   * @var string
+   */
+  protected $pluginId;
+
+  /**
+   * Mocked plugin definition.
+   *
+   * @var array
+   */
+  protected $pluginDefinition;
+
+  /**
+   * Mocked logger.
+   *
+   * @var \Drupal\Core\Logger\LoggerChannelInterface
+   */
+  protected $logger;
+
+  /**
+   * Mocked entity type manager.
+   *
+   * @var \Drupal\Core\Entity\EntityTypeManagerInterface
+   */
+  protected $entityTypeManager;
+
+  /**
+   * Mocked renderer.
+   *
+   * @var \Drupal\Core\Render\RendererInterface
+   */
+  protected $renderer;
+
+  /**
+   * Mocked phone number provider (entity).
+   *
+   * @var \Drupal\sms\Provider\PhoneNumberProviderInterface
+   */
+  protected $phoneNumberProvider;
+
+  /**
+   * Mocked phone number provider (number).
+   *
+   * @var \Drupal\sms\Provider\SmsProviderInterface
+   */
+  protected $smsProvider;
+
+  /**
+   * Rendered message.
+   *
+   * @var array
+   */
+  protected $output;
+
+  /**
+   * Test setup.
+   */
+  public function setUp() {
+    parent::setUp();
+
+    // SmsMessage.php#L326 is calling uuid service directly. Need to setup
+    // fake container for this test.
+    $container = new ContainerBuilder();
+    $container->set('uuid', $this->getMockUuidService());
+    \Drupal::setContainer($container);
+
+    $this->entityConfiguration = [];
+    $this->numberConfiguration = ['phone_number' => '18001234567'];
+    $this->pluginId = $this->randomMachineName();
+    $this->pluginDefinition = [
+      'title' => $this->randomMachineName(),
+      'viewModes' => [
+        'sms_message',
+      ],
+    ];
+    $this->logger = $this->prophesize(LoggerChannelInterface::class)->reveal();
+    $this->entityTypeManager = $this->prophesize(EntityTypeManagerInterface::class)->reveal();
+    $this->renderer = $this->prophesize(RendererInterface::class)->reveal();
+    $this->phoneNumberProvider = $this->prophesize(PhoneNumberProviderInterface::class)->reveal();
+    $this->smsProvider = $this->prophesize(SmsProviderInterface::class)->reveal();
+
+    $this->output = ['sms_message' => 'Hello, World!'];
+  }
+
+  /**
+   * Test Sms::deliver empty message.
+   *
+   * @covers \Drupal\message_notify_sms\Plugin\Notifier\Sms::deliver
+   */
+  public function testDeliverEmptyMessage() {
+    $this->logger = $this->getMockLogger('warning');
+    $notifier = $this->getEntityNotifier();
+
+    $this->assertFalse($notifier->deliver(['sms_message' => '']));
+  }
+
+  /**
+   * Test Sms::deliver entity with happy path.
+   *
+   * @covers \Drupal\message_notify_sms\Plugin\Notifier\Sms::deliver
+   */
+  public function testDeliverEntity() {
+    $this->phoneNumberProvider = $this->getMockRespondingPhoneNumberProvider(FALSE);
+    $this->logger = $this->getMockLogger('info');
+    $notifier = $this->getEntityNotifier();
+
+    $this->assertTrue($notifier->deliver($this->output));
+  }
+
+  /**
+   * Test Sms::deliver entity that has no phone number.
+   *
+   * @covers \Drupal\message_notify_sms\Plugin\Notifier\Sms::deliver
+   */
+  public function testDeliverEntityNoPhoneNumber() {
+    $this->phoneNumberProvider = $this->getMockThrowingPhoneProvider(NoPhoneNumberException::class);
+    $this->logger = $this->getMockLogger('error');
+    $notifier = $this->getEntityNotifier();
+
+    $this->assertFalse($notifier->deliver($this->output));
+  }
+
+  /**
+   * Test Sms::deliver entity with a random exception.
+   *
+   * @covers \Drupal\message_notify_sms\Plugin\Notifier\Sms::deliver
+   */
+  public function testDeliverEntityRandomException() {
+    $this->phoneNumberProvider = $this->getMockThrowingPhoneProvider(Exception::class);
+    $this->logger = $this->getMockLogger('error');
+    $notifier = $this->getEntityNotifier();
+
+    $this->assertFalse($notifier->deliver($this->output));
+  }
+
+  /**
+   * Test Sms::deliver number happy path.
+   *
+   * @covers \Drupal\message_notify_sms\Plugin\Notifier\Sms::deliver
+   */
+  public function testDeliverNumber() {
+    $this->logger = $this->getMockLogger('info');
+    $this->smsProvider = $this->getMockRespondingSmsProvider(NULL);
+    $notifier = $this->getNumberNotifier();
+
+    $this->assertTrue($notifier->deliver($this->output));
+  }
+
+  /**
+   * Test Sms::deliver number with message that has no direction.
+   *
+   * @covers \Drupal\message_notify_sms\Plugin\Notifier\Sms::deliver
+   */
+  public function testDeliverNumberNoDirection() {
+    $this->logger = $this->getMockLogger('error');
+    $this->smsProvider = $this->getMockThrowingSmsProvider(SmsDirectionException::class);
+    $notifier = $this->getNumberNotifier();
+
+    $this->assertFalse($notifier->deliver($this->output));
+  }
+
+  /**
+   * Test Sms::deliver number with no gateway.
+   *
+   * @covers \Drupal\message_notify_sms\Plugin\Notifier\Sms::deliver
+   */
+  public function testDeliverNumberRouteException() {
+    $this->logger = $this->getMockLogger('error');
+    $this->smsProvider = $this->getMockThrowingSmsProvider(RecipientRouteException::class);
+    $notifier = $this->getNumberNotifier();
+
+    $this->assertFalse($notifier->deliver($this->output));
+  }
+
+  /**
+   * Test Sms::deliver number with a random exception.
+   *
+   * @covers \Drupal\message_notify_sms\Plugin\Notifier\Sms::deliver
+   */
+  public function testDeliverNumberRandomException() {
+    $this->logger = $this->getMockLogger('error');
+    $this->smsProvider = $this->getMockThrowingSmsProvider(Exception::class);
+    $notifier = $this->getNumberNotifier();
+
+    $this->assertFalse($notifier->deliver($this->output));
+  }
+
+  /**
+   * Returns a mocked logger expecting a single info call.
+   *
+   * @param string $level
+   *   The log level.
+   *
+   * @return object
+   *   The mock logger.
+   */
+  protected function getMockLogger($level) {
+    $logger = $this->prophesize(LoggerChannelInterface::class);
+    $logger
+      ->$level(Argument::type('string'), Argument::type('array'))
+      ->shouldBeCalledTimes(1);
+
+    return $logger->reveal();
+  }
+
+  /**
+   * Returns a mocked PhoneNumberProvider that returns the specified value.
+   *
+   * @param mixed $return_value
+   *   The value PhoneNumberProvider::sendMessage should return.
+   *
+   * @return object
+   *   The mock PhoneNumberProvider.
+   */
+  protected function getMockRespondingPhoneNumberProvider($return_value) {
+    $phoneNumberProvider = $this->prophesize(PhoneNumberProviderInterface::class);
+    $phoneNumberProvider
+      ->sendMessage(Argument::type('Drupal\user\UserInterface'), Argument::type('Drupal\sms\Message\SmsMessageInterface'))
+      ->willReturn($return_value);
+
+    return $phoneNumberProvider->reveal();
+  }
+
+  /**
+   * Returns a mocked PhoneNumberProvider that throws the specified exception.
+   *
+   * @param string $thrown_class
+   *   The exception PhoneNumberProvider::sendMessage should throw.
+   *
+   * @return object
+   *   The mock PhoneNumberProvider.
+   */
+  protected function getMockThrowingPhoneProvider($thrown_class) {
+    $phoneNumberProvider = $this->prophesize(PhoneNumberProviderInterface::class);
+    $phoneNumberProvider
+      ->sendMessage(Argument::type('Drupal\user\UserInterface'), Argument::type('Drupal\sms\Message\SmsMessageInterface'))
+      ->willThrow($thrown_class);
+
+    return $phoneNumberProvider->reveal();
+  }
+
+  /**
+   * Returns a mocked SmsProvider that returns the specified value.
+   *
+   * @param mixed $return_value
+   *   The value SmsProvider::sendMessage should return.
+   *
+   * @return object
+   *   The mock SmsProvider.
+   */
+  protected function getMockRespondingSmsProvider($return_value) {
+    $smsProvider = $this->prophesize(SmsProviderInterface::class);
+    $smsProvider
+      ->queue(Argument::type('Drupal\sms\Message\SmsMessageInterface'))
+      ->willReturn($return_value);
+
+    return $smsProvider->reveal();
+  }
+
+  /**
+   * Returns a mocked SmsProvider that throws the specified exception.
+   *
+   * @param string $thrown_class
+   *   The exception SmsProvider::sendMessage should throw.
+   *
+   * @return object
+   *   The mock SmsProvider.
+   */
+  protected function getMockThrowingSmsProvider($thrown_class) {
+    $smsProvider = $this->prophesize(SmsProviderInterface::class);
+    $smsProvider
+      ->queue(Argument::type('Drupal\sms\Message\SmsMessageInterface'))
+      ->willThrow($thrown_class);
+
+    return $smsProvider->reveal();
+
+  }
+
+  /**
+   * Returns a mocked User.
+   *
+   * @return object
+   *   The mocked user.
+   */
+  protected function getMockUser() {
+    $user = $this->prophesize(UserInterface::class);
+    $user->id()->willReturn(42);
+    $user->getAccountName()->willReturn('user');
+    $user->getEmail()->willReturn('user@example.com');
+    $user->getPreferredLangcode()->willReturn(Language::LANGCODE_DEFAULT);
+
+    return $user->reveal();
+  }
+
+  /**
+   * Returns a mocked Message.
+   *
+   * @param \Drupal\user\UserInterface $user
+   *   The user object that owns the message.
+   *
+   * @return object
+   *   The mocked Message
+   */
+  protected function getMockMessage(UserInterface $user) {
+    $message = $this->prophesize(MessageInterface::class);
+    $message->getOwner()->willReturn($user);
+    $message->getOwnerId()->willReturn(42);
+
+    return $message->reveal();
+  }
+
+  /**
+   * Returns a mocked Notifier plugin tied to an entity.
+   *
+   * @return \Drupal\message_notify_sms\Plugin\Notifier\Sms
+   *   The notifier instance.
+   */
+  protected function getEntityNotifier() {
+    $user = $this->getMockUser();
+    $message = $this->getMockMessage($user);
+
+    return new Sms(
+      $this->entityConfiguration,
+      $this->pluginId,
+      $this->pluginDefinition,
+      $this->logger,
+      $this->entityTypeManager,
+      $this->renderer,
+      $message,
+      $this->phoneNumberProvider,
+      $this->smsProvider
+    );
+  }
+
+  /**
+   * Returns a mocked Notifier plugin with manual options.
+   *
+   * @return \Drupal\message_notify_sms\Plugin\Notifier\Sms
+   *   The notifier instance.
+   */
+  protected function getNumberNotifier() {
+    return new Sms(
+      $this->numberConfiguration,
+      $this->pluginId,
+      $this->pluginDefinition,
+      $this->logger,
+      $this->entityTypeManager,
+      $this->renderer,
+      NULL,
+      $this->phoneNumberProvider,
+      $this->smsProvider
+    );
+  }
+
+  /**
+   * Returns a mocked UUID service.
+   *
+   * @return \Prophecy\Prophecy\ObjectProphecy
+   *   The mocked UUID service.
+   */
+  protected function getMockUuidService() {
+    $uuid = $this->prophesize(UuidInterface::class);
+    $uuid->generate(Argument::any())->willReturn(42);
+
+    return $uuid;
+  }
+
+}
diff --git a/modules/message_notify_sms_test/config/install/core.entity_form_display.user.user.default.yml b/modules/message_notify_sms_test/config/install/core.entity_form_display.user.user.default.yml
new file mode 100644
index 0000000..245c6d2
--- /dev/null
+++ b/modules/message_notify_sms_test/config/install/core.entity_form_display.user.user.default.yml
@@ -0,0 +1,43 @@
+langcode: en
+status: true
+dependencies:
+  config:
+    - field.field.user.user.field_sms
+  module:
+    - path
+    - sms
+    - user
+id: user.user.default
+targetEntityType: user
+bundle: user
+mode: default
+content:
+  account:
+    weight: -10
+    settings: {  }
+    third_party_settings: {  }
+    region: content
+  field_sms:
+    weight: 31
+    settings:
+      placeholder: ''
+    third_party_settings: {  }
+    type: sms_telephone
+    region: content
+  language:
+    weight: 0
+    settings: {  }
+    third_party_settings: {  }
+    region: content
+  path:
+    type: path
+    weight: 30
+    region: content
+    settings: {  }
+    third_party_settings: {  }
+  timezone:
+    weight: 6
+    settings: {  }
+    third_party_settings: {  }
+    region: content
+hidden: {  }
diff --git a/modules/message_notify_sms_test/config/install/core.entity_view_display.message.message_notify_sms_test.sms_message.yml b/modules/message_notify_sms_test/config/install/core.entity_view_display.message.message_notify_sms_test.sms_message.yml
new file mode 100644
index 0000000..d67a34c
--- /dev/null
+++ b/modules/message_notify_sms_test/config/install/core.entity_view_display.message.message_notify_sms_test.sms_message.yml
@@ -0,0 +1,19 @@
+langcode: en
+status: true
+dependencies:
+  config:
+    - core.entity_view_mode.message.sms_message
+    - field.field.message.message_notify_sms_test.message_notify_sms_test_text
+    - message.template.message_notify_sms_test
+id: message.message_notify_sms_test.sms_message
+targetEntityType: message
+bundle: message_notify_sms_test
+mode: sms_message
+content:
+  message_notify_sms_test_text:
+    weight: -10
+    settings: { }
+    third_party_settings: { }
+    label: hidden
+hidden:
+  partial_0: true
diff --git a/modules/message_notify_sms_test/config/install/field.field.message.message_notify_sms_test.message_notify_sms_test_text.yml b/modules/message_notify_sms_test/config/install/field.field.message.message_notify_sms_test.message_notify_sms_test_text.yml
new file mode 100644
index 0000000..9efc6bf
--- /dev/null
+++ b/modules/message_notify_sms_test/config/install/field.field.message.message_notify_sms_test.message_notify_sms_test_text.yml
@@ -0,0 +1,18 @@
+langcode: en
+status: true
+dependencies:
+  config:
+    - field.storage.message.message_notify_sms_test_text
+    - message.template.message_notify_sms_test
+id: message.message_notify_sms_test.message_notify_sms_test_text
+field_name: message_notify_sms_test_text
+entity_type: message
+bundle: message_notify_sms_test
+label: 'Message text'
+description: ''
+required: true
+translatable: false
+default_value: {  }
+default_value_callback: ''
+settings: {  }
+field_type: string_long
diff --git a/modules/message_notify_sms_test/config/install/field.field.user.user.field_sms.yml b/modules/message_notify_sms_test/config/install/field.field.user.user.field_sms.yml
new file mode 100644
index 0000000..27616c4
--- /dev/null
+++ b/modules/message_notify_sms_test/config/install/field.field.user.user.field_sms.yml
@@ -0,0 +1,20 @@
+langcode: en
+status: true
+dependencies:
+  config:
+    - field.storage.user.field_sms
+  module:
+    - telephone
+    - user
+id: user.user.field_sms
+field_name: field_sms
+entity_type: user
+bundle: user
+label: SMS
+description: ''
+required: false
+translatable: false
+default_value: {  }
+default_value_callback: ''
+settings: {  }
+field_type: telephone
diff --git a/modules/message_notify_sms_test/config/install/field.storage.message.message_notify_sms_test_text.yml b/modules/message_notify_sms_test/config/install/field.storage.message.message_notify_sms_test_text.yml
new file mode 100644
index 0000000..420ff53
--- /dev/null
+++ b/modules/message_notify_sms_test/config/install/field.storage.message.message_notify_sms_test_text.yml
@@ -0,0 +1,19 @@
+langcode: en
+status: true
+dependencies:
+  module:
+    - field
+    - message
+id: message.message_notify_sms_test_text
+field_name: message_notify_sms_test_text
+entity_type: message
+type: string_long
+settings:
+  case_sensitive: false
+module: core
+locked: false
+cardinality: 1
+translatable: true
+indexes: {  }
+persist_with_no_fields: false
+custom_storage: false
diff --git a/modules/message_notify_sms_test/config/install/field.storage.user.field_sms.yml b/modules/message_notify_sms_test/config/install/field.storage.user.field_sms.yml
new file mode 100644
index 0000000..bde76b3
--- /dev/null
+++ b/modules/message_notify_sms_test/config/install/field.storage.user.field_sms.yml
@@ -0,0 +1,18 @@
+langcode: en
+status: true
+dependencies:
+  module:
+    - telephone
+    - user
+id: user.field_sms
+field_name: field_sms
+entity_type: user
+type: telephone
+settings: {  }
+module: telephone
+locked: false
+cardinality: 1
+translatable: true
+indexes: {  }
+persist_with_no_fields: false
+custom_storage: false
diff --git a/modules/message_notify_sms_test/config/install/message.template.message_notify_sms_test.yml b/modules/message_notify_sms_test/config/install/message.template.message_notify_sms_test.yml
new file mode 100644
index 0000000..61c691f
--- /dev/null
+++ b/modules/message_notify_sms_test/config/install/message.template.message_notify_sms_test.yml
@@ -0,0 +1,16 @@
+langcode: en
+status: true
+dependencies: {  }
+template: message_notify_sms_test
+label: 'Message Notify SMS Test'
+description: 'Message template for testing purposes.'
+text:
+  -
+    value: "<p>Partial</p>"
+    format: basic_html
+settings:
+  'token options':
+    clear: false
+    'token replace': true
+  purge_override: false
+  purge_methods: {  }
diff --git a/modules/message_notify_sms_test/config/install/sms.phone.user.user.yml b/modules/message_notify_sms_test/config/install/sms.phone.user.user.yml
new file mode 100644
index 0000000..a856d94
--- /dev/null
+++ b/modules/message_notify_sms_test/config/install/sms.phone.user.user.yml
@@ -0,0 +1,15 @@
+langcode: en
+status: true
+dependencies:
+  config:
+    - field.field.user.user.field_sms
+id: user.user
+entity_type: user
+bundle: user
+automated_optout: null
+verification_message: "Your verification code is '[sms-message:verification-code]'.\r\nGo to [sms:verification-url] to verify your phone number.\r\n- [site:name]"
+verification_code_lifetime: 3600
+purge_verification_phone_number: true
+fields:
+  phone_number: field_sms
+  automated_opt_out: ''
diff --git a/modules/message_notify_sms_test/message_notify_sms_test.info.yml b/modules/message_notify_sms_test/message_notify_sms_test.info.yml
new file mode 100644
index 0000000..b699401
--- /dev/null
+++ b/modules/message_notify_sms_test/message_notify_sms_test.info.yml
@@ -0,0 +1,8 @@
+name: 'Message Notify SMS Test'
+description: 'Installs assisting config for testing message_notify_sms'
+type: module
+core: 8.x
+dependencies:
+  - field
+  - message_notify_sms
+package: Testing
diff --git a/src/Plugin/Notifier/Email.php b/src/Plugin/Notifier/Email.php
index 7e133be..3ad6d5e 100644
--- a/src/Plugin/Notifier/Email.php
+++ b/src/Plugin/Notifier/Email.php
@@ -56,10 +56,7 @@ class Email extends MessageNotifierBase {
    */
   public function __construct(array $configuration, $plugin_id, $plugin_definition, LoggerChannelInterface $logger, EntityTypeManagerInterface $entity_type_manager, RendererInterface $render, MessageInterface $message = NULL, MailManagerInterface $mail_manager) {
     // Set configuration defaults.
-    $configuration += [
-      'mail' => FALSE,
-      'language override' => FALSE,
-    ];
+    $configuration = $configuration + ['mail' => FALSE];
 
     parent::__construct($configuration, $plugin_id, $plugin_definition, $logger, $entity_type_manager, $render, $message);
 
diff --git a/src/Plugin/Notifier/MessageNotifierBase.php b/src/Plugin/Notifier/MessageNotifierBase.php
index a1b500c..96cc2a2 100644
--- a/src/Plugin/Notifier/MessageNotifierBase.php
+++ b/src/Plugin/Notifier/MessageNotifierBase.php
@@ -68,6 +68,7 @@ public function __construct(array $configuration, $plugin_id, $plugin_definition
     $configuration += [
       'save on success' => TRUE,
       'save on fail' => FALSE,
+      'language override' => FALSE,
     ];
     parent::__construct($configuration, $plugin_id, $plugin_definition);
 
diff --git a/src/Plugin/Notifier/Sms.php b/src/Plugin/Notifier/Sms.php
deleted file mode 100644
index 4d14ca1..0000000
--- a/src/Plugin/Notifier/Sms.php
+++ /dev/null
@@ -1,34 +0,0 @@
-<?php
-
-namespace Drupal\message_notify\Plugin\Notifier;
-
-use Drupal\message_notify\Exception\MessageNotifyException;
-
-/**
- * SMS notifier.
- *
- * @todo Add plugin definition.
- */
-class Sms extends MessageNotifierBase {
-
-  /**
-   * {@inheritdoc}
-   */
-  public function deliver(array $output = []) {
-    throw new MessageNotifyException('This functionality depends on the SMS Framework module. See: https://www.drupal.org/node/2582937');
-    if (empty($this->message->smsNumber)) {
-      // Try to get the SMS number from the account.
-      $account = $this->message->uid->entitiy;
-      if (!empty($account->sms_user['number'])) {
-        $this->message->smsNumber = $account->sms_user['number'];
-      }
-    }
-
-    if (empty($this->message->smsNumber)) {
-      throw new MessageNotifyException('Message cannot be sent using SMS as the "smsNumber" property is missing from the Message entity or user entity.');
-    }
-
-    return sms_send($this->message->smsNumber, strip_tags($output['message_notify_sms_body']));
-  }
-
-}