diff --git a/lib/API/JSON/v1/Services.php b/lib/API/JSON/v1/Services.php
index dcca235a83..7885e501ca 100644
--- a/lib/API/JSON/v1/Services.php
+++ b/lib/API/JSON/v1/Services.php
@@ -40,9 +40,9 @@ class Services extends APIEndpoint {
     $state = !empty($result['state']) ? $result['state'] : null;
 
     $success_message = null;
-    if($state == Bridge::MAILPOET_KEY_VALID) {
+    if($state == Bridge::PREMIUM_KEY_VALID) {
       $success_message = __('Your MailPoet Sending Service key has been successfully validated.', 'mailpoet');
-    } elseif($state == Bridge::MAILPOET_KEY_EXPIRING) {
+    } elseif($state == Bridge::PREMIUM_KEY_EXPIRING) {
       $success_message = sprintf(
         __('Your MailPoet Sending Service key expires on %s!', 'mailpoet'),
         $this->date_time->formatDate(strtotime($result['data']['expire_at']))
@@ -54,7 +54,7 @@ class Services extends APIEndpoint {
     }
 
     switch($state) {
-      case Bridge::MAILPOET_KEY_INVALID:
+      case Bridge::PREMIUM_KEY_INVALID:
         $error = __('Your MailPoet Sending Service key is invalid.', 'mailpoet');
         break;
       default:
diff --git a/lib/Config/ServicesChecker.php b/lib/Config/ServicesChecker.php
index 9e89433058..47f039733d 100644
--- a/lib/Config/ServicesChecker.php
+++ b/lib/Config/ServicesChecker.php
@@ -22,7 +22,7 @@ class ServicesChecker {
 
     if(!$mss_key_specified
       || empty($mss_key['state'])
-      || $mss_key['state'] == Bridge::MAILPOET_KEY_INVALID
+      || $mss_key['state'] == Bridge::PREMIUM_KEY_INVALID
     ) {
       if($display_error_notice) {
         $error = Helpers::replaceLinkTags(
@@ -33,7 +33,7 @@ class ServicesChecker {
         WPNotice::displayError($error);
       }
       return false;
-    } elseif($mss_key['state'] == Bridge::MAILPOET_KEY_EXPIRING
+    } elseif($mss_key['state'] == Bridge::PREMIUM_KEY_EXPIRING
       && !empty($mss_key['data']['expire_at'])
     ) {
       if($display_error_notice) {
@@ -48,7 +48,7 @@ class ServicesChecker {
         WPNotice::displayWarning($error);
       }
       return true;
-    } elseif($mss_key['state'] == Bridge::MAILPOET_KEY_VALID) {
+    } elseif($mss_key['state'] == Bridge::PREMIUM_KEY_VALID) {
       return true;
     }
 
diff --git a/lib/Services/Bridge.php b/lib/Services/Bridge.php
index d633e90a8a..30c9e29f3e 100644
--- a/lib/Services/Bridge.php
+++ b/lib/Services/Bridge.php
@@ -14,12 +14,6 @@ class Bridge {
   const PREMIUM_KEY_SETTING_NAME = 'premium.premium_key';
   const PREMIUM_KEY_STATE_SETTING_NAME = 'premium.premium_key_state';
 
-  const MAILPOET_KEY_VALID = 'valid';
-  const MAILPOET_KEY_INVALID = 'invalid';
-  const MAILPOET_KEY_EXPIRING = 'expiring';
-
-  const MAILPOET_KEY_CHECK_ERROR = 'check_error';
-
   const PREMIUM_KEY_VALID = 'valid';
   const PREMIUM_KEY_INVALID = 'invalid';
   const PREMIUM_KEY_EXPIRING = 'expiring';
@@ -68,15 +62,15 @@ class Bridge {
 
   private function processMSSKeyCheckResult(array $result) {
     $state_map = array(
-      200 => self::MAILPOET_KEY_VALID,
-      401 => self::MAILPOET_KEY_INVALID,
-      402 => self::MAILPOET_KEY_EXPIRING
+      200 => self::PREMIUM_KEY_VALID,
+      401 => self::PREMIUM_KEY_INVALID,
+      402 => self::PREMIUM_KEY_EXPIRING
     );
 
     if(!empty($result['code']) && isset($state_map[$result['code']])) {
       $key_state = $state_map[$result['code']];
     } else {
-      $key_state = self::MAILPOET_KEY_CHECK_ERROR;
+      $key_state = self::PREMIUM_KEY_CHECK_ERROR;
     }
 
     return $this->buildKeyState(
@@ -87,7 +81,7 @@ class Bridge {
 
   function storeMSSKeyAndState($key, $state) {
     if(empty($state['state'])
-      || $state['state'] === self::MAILPOET_KEY_CHECK_ERROR
+      || $state['state'] === self::PREMIUM_KEY_CHECK_ERROR
     ) {
       return false;
     }
@@ -168,8 +162,8 @@ class Bridge {
 
   function updateSubscriberCount($result) {
     if(!empty($result['state'])
-      && ($result['state'] === self::MAILPOET_KEY_VALID
-      || $result['state'] === self::MAILPOET_KEY_EXPIRING)
+      && ($result['state'] === self::PREMIUM_KEY_VALID
+      || $result['state'] === self::PREMIUM_KEY_EXPIRING)
     ) {
       return $this->api->updateSubscriberCount(Subscriber::getTotalSubscribers());
     }
@@ -179,7 +173,7 @@ class Bridge {
   static function invalidateKey() {
     Setting::setValue(
       self::API_KEY_STATE_SETTING_NAME,
-      array('state' => self::MAILPOET_KEY_INVALID)
+      array('state' => self::PREMIUM_KEY_INVALID)
     );
   }
 
diff --git a/tests/unit/API/JSON/v1/ServicesTest.php b/tests/unit/API/JSON/v1/ServicesTest.php
index d6cc898201..cc566e97d5 100644
--- a/tests/unit/API/JSON/v1/ServicesTest.php
+++ b/tests/unit/API/JSON/v1/ServicesTest.php
@@ -23,7 +23,7 @@ class ServicesTest extends \MailPoetTest {
     $this->services_endpoint->bridge = Stub::make(
       new Bridge(),
       array(
-        'checkMSSKey' => array('state' => Bridge::MAILPOET_KEY_VALID),
+        'checkMSSKey' => array('state' => Bridge::PREMIUM_KEY_VALID),
         'storeMSSKeyAndState' => Stub::once()
       ),
       $this
@@ -36,7 +36,7 @@ class ServicesTest extends \MailPoetTest {
     $this->services_endpoint->bridge = Stub::make(
       new Bridge(),
       array(
-        'checkMSSKey' => array('state' => Bridge::MAILPOET_KEY_INVALID),
+        'checkMSSKey' => array('state' => Bridge::PREMIUM_KEY_INVALID),
         'storeMSSKeyAndState' => Stub::once()
       ),
       $this
@@ -51,7 +51,7 @@ class ServicesTest extends \MailPoetTest {
       new Bridge(),
       array(
         'checkMSSKey' => array(
-          'state' => Bridge::MAILPOET_KEY_EXPIRING,
+          'state' => Bridge::PREMIUM_KEY_EXPIRING,
           'data' => array('expire_at' => $date->format('c'))
         ),
         'storeMSSKeyAndState' => Stub::once()
diff --git a/tests/unit/Config/ServicesCheckerTest.php b/tests/unit/Config/ServicesCheckerTest.php
index a9b0202b40..398994d95c 100644
--- a/tests/unit/Config/ServicesCheckerTest.php
+++ b/tests/unit/Config/ServicesCheckerTest.php
@@ -34,7 +34,7 @@ class ServicesCheckerTest extends \MailPoetTest {
   function testItReturnsTrueIfMSSKeyIsValid() {
     Setting::setValue(
       Bridge::API_KEY_STATE_SETTING_NAME,
-      array('state' => Bridge::MAILPOET_KEY_VALID)
+      array('state' => Bridge::PREMIUM_KEY_VALID)
     );
     $result = $this->services_checker->isMailPoetAPIKeyValid();
     expect($result)->true();
@@ -43,7 +43,7 @@ class ServicesCheckerTest extends \MailPoetTest {
   function testItReturnsFalseIfMSSKeyIsInvalid() {
     Setting::setValue(
       Bridge::API_KEY_STATE_SETTING_NAME,
-      array('state' => Bridge::MAILPOET_KEY_INVALID)
+      array('state' => Bridge::PREMIUM_KEY_INVALID)
     );
     $result = $this->services_checker->isMailPoetAPIKeyValid();
     expect($result)->false();
@@ -53,7 +53,7 @@ class ServicesCheckerTest extends \MailPoetTest {
     Setting::setValue(
       Bridge::API_KEY_STATE_SETTING_NAME,
       array(
-        'state' => Bridge::MAILPOET_KEY_EXPIRING,
+        'state' => Bridge::PREMIUM_KEY_EXPIRING,
         'data' => array('expire_at' => date('c'))
       )
     );
diff --git a/tests/unit/Cron/Workers/KeyCheck/SendingServiceKeyCheckTest.php b/tests/unit/Cron/Workers/KeyCheck/SendingServiceKeyCheckTest.php
index 93814e84bc..3b50d1740b 100644
--- a/tests/unit/Cron/Workers/KeyCheck/SendingServiceKeyCheckTest.php
+++ b/tests/unit/Cron/Workers/KeyCheck/SendingServiceKeyCheckTest.php
@@ -20,7 +20,7 @@ class SendingServiceKeyCheckTest extends \MailPoetTest {
   }
 
   function testItChecksMSSKey() {
-    $response = array('code' => Bridge::MAILPOET_KEY_VALID);
+    $response = array('code' => Bridge::PREMIUM_KEY_VALID);
     $this->worker->bridge = Stub::make(
       new Bridge,
       array(
diff --git a/tests/unit/Services/BridgeTest.php b/tests/unit/Services/BridgeTest.php
index 27e6184764..4988efb82f 100644
--- a/tests/unit/Services/BridgeTest.php
+++ b/tests/unit/Services/BridgeTest.php
@@ -51,19 +51,19 @@ class BridgeTest extends \MailPoetTest {
   function testItChecksValidMSSKey() {
     $result = $this->bridge->checkMSSKey($this->valid_key);
     expect($result)->notEmpty();
-    expect($result['state'])->equals(Bridge::MAILPOET_KEY_VALID);
+    expect($result['state'])->equals(Bridge::PREMIUM_KEY_VALID);
   }
 
   function testItChecksInvalidMSSKey() {
     $result = $this->bridge->checkMSSKey($this->invalid_key);
     expect($result)->notEmpty();
-    expect($result['state'])->equals(Bridge::MAILPOET_KEY_INVALID);
+    expect($result['state'])->equals(Bridge::PREMIUM_KEY_INVALID);
   }
 
   function testItChecksExpiringMSSKey() {
     $result = $this->bridge->checkMSSKey($this->expiring_key);
     expect($result)->notEmpty();
-    expect($result['state'])->equals(Bridge::MAILPOET_KEY_EXPIRING);
+    expect($result['state'])->equals(Bridge::PREMIUM_KEY_EXPIRING);
     expect($result['data']['expire_at'])->notEmpty();
   }
 
@@ -72,14 +72,14 @@ class BridgeTest extends \MailPoetTest {
     $this->bridge->api = $api;
     $result = $this->bridge->checkMSSKey($this->valid_key);
     expect($result)->notEmpty();
-    expect($result['state'])->equals(Bridge::MAILPOET_KEY_CHECK_ERROR);
+    expect($result['state'])->equals(Bridge::PREMIUM_KEY_CHECK_ERROR);
   }
 
   function testItStoresExpectedMSSKeyStates() {
     $states = array(
-      Bridge::MAILPOET_KEY_VALID => $this->valid_key,
-      Bridge::MAILPOET_KEY_INVALID => $this->invalid_key,
-      Bridge::MAILPOET_KEY_EXPIRING => $this->expiring_key
+      Bridge::PREMIUM_KEY_VALID => $this->valid_key,
+      Bridge::PREMIUM_KEY_INVALID => $this->invalid_key,
+      Bridge::PREMIUM_KEY_EXPIRING => $this->expiring_key
     );
     foreach($states as $state => $key) {
       $state = array('state' => $state);
@@ -91,7 +91,7 @@ class BridgeTest extends \MailPoetTest {
 
   function testItDoesNotStoreErroneousOrUnexpectedMSSKeyStates() {
     $states = array(
-      array('state' => Bridge::MAILPOET_KEY_CHECK_ERROR),
+      array('state' => Bridge::PREMIUM_KEY_CHECK_ERROR),
       array()
     );
     foreach($states as $state) {
@@ -164,14 +164,14 @@ class BridgeTest extends \MailPoetTest {
   function testItUpdatesSubscriberCount() {
     // it performs update if the key is valid or expiring
     $result = array();
-    $result['state'] = Bridge::MAILPOET_KEY_VALID;
+    $result['state'] = Bridge::PREMIUM_KEY_VALID;
     $updated = $this->bridge->updateSubscriberCount($result);
     expect($updated)->true();
-    $result['state'] = Bridge::MAILPOET_KEY_EXPIRING;
+    $result['state'] = Bridge::PREMIUM_KEY_EXPIRING;
     $updated = $this->bridge->updateSubscriberCount($result);
     expect($updated)->true();
     // it does not perform update if the key is invalid
-    $result['state'] = Bridge::MAILPOET_KEY_INVALID;
+    $result['state'] = Bridge::PREMIUM_KEY_INVALID;
     $updated = $this->bridge->updateSubscriberCount($result);
     expect($updated)->null();
   }
@@ -179,10 +179,10 @@ class BridgeTest extends \MailPoetTest {
   function testItInvalidatesMSSKey() {
     Setting::setValue(
       Bridge::API_KEY_STATE_SETTING_NAME,
-      array('state' => Bridge::MAILPOET_KEY_VALID)
+      array('state' => Bridge::PREMIUM_KEY_VALID)
     );
     Bridge::invalidateKey();
-    expect($this->getMSSKeyState())->equals(array('state' => Bridge::MAILPOET_KEY_INVALID));
+    expect($this->getMSSKeyState())->equals(array('state' => Bridge::PREMIUM_KEY_INVALID));
   }
 
   function testItChecksAndStoresKeysOnSettingsSave() {