diff --git a/README.md b/README.md
index 5df477c..3c018f9 100644
--- a/README.md
+++ b/README.md
@@ -124,6 +124,27 @@ $resubscribe = false;
 craft()->oneCampaignMonitor_subscribers->add($list_id, $email, $name, $customFields, $resubscribe);
 ```
 
+Update a subscriber in a list:
+
+```
+$list_id = '123';
+$email = 'email@email.com';
+$name = 'Steve';
+$customFields = ['city': 'New York'];
+$resubscribe = true;
+craft()->oneCampaignMonitor_subscribers->update($list_id, $email, $name, $customFields, $resubscribe);
+```
+
+Determine if a subscriber exists in a list:
+
+```
+$list_id = '123';
+$email = 'email@email.com';
+if (craft()->oneCampaignMonitor_subscribers->exists($list_id, $email)) {
+  // subscriber exists
+}
+```
+
 ### Checking if the user has subscribed to a list
 
 You can check in a template if the current user (by session) has already subscribed to a list:
diff --git a/consolecommands/OneCampaignMonitorSubscribersCommand.php b/consolecommands/OneCampaignMonitorSubscribersCommand.php
new file mode 100644
index 0000000..b5c424e
--- /dev/null
+++ b/consolecommands/OneCampaignMonitorSubscribersCommand.php
@@ -0,0 +1,67 @@
+<?php
+namespace Craft;
+
+class OneCampaignMonitorSubscribersCommand extends BaseCommand {
+
+    /**
+     * Adds a subscriber to a list
+     * Usage:
+     *   php ./craft/app/etc/console/yiic onecampaignmonitorsubscribers add \
+     *       --listId="asdf..." \
+     *       --email="test@example.com" \
+     *       --name="Mr. Test" \
+     *       --resubscribe=1 \
+     *       --customFields='[{"Key":"City","Value":"Chicago"}]' \
+     */
+    public function actionAdd($listId, $email, $name=null, $customFields='[]', $resubscribe=true) {
+        $customFields = $this->_decodeCustomFields($customFields);
+        craft()->oneCampaignMonitor_subscribers->add($listId, $email, $name, $customFields, $resubscribe ? true : false);
+    }
+
+    /**
+     * Updates a subscriber in a list
+     * Usage:
+     *   php ./craft/app/etc/console/yiic onecampaignmonitorsubscribers update \
+     *       --listId="asdf..." \
+     *       --email="test@example.com" \
+     *       --name="Joan Doe" \
+     *       --resubscribe=0 \
+     *       --customFields='[{"Key":"City","Value":"New York"}]' \
+     *       --merge=1
+     */
+    public function actionUpdate($listId, $email, $name=null, $customFields='[]', $resubscribe=false, $merge=true) {
+        $customFields = $this->_decodeCustomFields($customFields);
+        craft()->oneCampaignMonitor_subscribers->update($listId, $email, $name, $customFields, $resubscribe ? true : false, $merge  ? true : false);
+    }
+
+    /**
+     * Determines is an email exists in a list
+     * Usage:
+     *   php ./craft/app/etc/console/yiic onecampaignmonitorsubscribers update \
+     *       --listId="asdf..." \
+     *       --email="test@example.com"
+     */
+    public function actionExists($listId, $email) {
+        if (craft()->oneCampaignMonitor_subscribers->exists($listId, $email)) {
+            OneCampaignMonitorPlugin::log('Subscriber exists in this list.', LogLevel::Info);
+        } else {
+            OneCampaignMonitorPlugin::log('Subscriber does not exist in the list.', LogLevel::Info);
+        }
+    }
+
+    /**
+     * Decodes the customFields input option
+     * @param  String $customFields JSON array of key/value objects
+     * @return Array
+     */
+    private function _decodeCustomFields($customFields) {
+        $decoded = json_decode($customFields, true);
+
+        if (!is_array($decoded)) {
+            throw new Exception('customFields must be specified as a JSON array of key/value objects');
+        }
+
+        return $decoded;
+    }
+
+}
diff --git a/services/OneCampaignMonitor_SubscribersService.php b/services/OneCampaignMonitor_SubscribersService.php
index 20e7c53..0478fe6 100644
--- a/services/OneCampaignMonitor_SubscribersService.php
+++ b/services/OneCampaignMonitor_SubscribersService.php
@@ -5,6 +5,16 @@
 
 class OneCampaignMonitor_SubscribersService extends OneCampaignMonitor_BaseService {
 
+    /**
+     * Adds a subscriber to a list
+     * @param  $listId
+     * @param  $email
+     * @param  $name
+     * @param  $customFields
+     * @param  $resubscribe
+     * @param  $merge
+     * @throws Exception
+     */
     public function add($listId, $email, $name=null, $customFields=array(), $resubscribe=true) {
         if (!$listId) {
             throw new Exception('List ID is required');
@@ -29,4 +39,82 @@ public function add($listId, $email, $name=null, $customFields=array(), $resubsc
         return true;
     }
 
+    /**
+     * Determines is a subscriber exists in a list
+     * @param  $listId
+     * @param  $email
+     * @return  Boolean
+     * @throws Exception
+     */
+    public function exists($listId, $email) {
+        if (!$listId) {
+            throw new Exception('List ID is required');
+        }
+        if (!$email) {
+            throw new Exception('Please provide a valid email address');
+        }
+
+        $connection = new \CS_REST_Subscribers($listId, $this->auth());
+
+        $result = $connection->get($email);
+            
+        $error = null;
+        return $this->response($result, $error);
+    }
+
+    /**
+     * Updates a subscriber in a list
+     * @param  $listId
+     * @param  $email
+     * @param  $name
+     * @param  $customFields
+     * @param  Boolean $resubscribe Re-activate an existing user if they have been deactivated
+     * @param  Boolean $mergeMultiFields Multi-Valued Select Many fields will be merged together instead of overwritten
+     * @throws Exception
+     */
+    public function update($listId, $email, $name=null, $customFields=array(), $resubscribe=false, $mergeMultiFields=false) {
+        if (!$listId) {
+            throw new Exception('List ID is required');
+        }
+        if (!$email) {
+            throw new Exception('Please provide a valid email address');
+        }
+
+        $connection = new \CS_REST_Subscribers($listId, $this->auth());
+        
+        $subscriber = [
+            'Resubscribe' => $resubscribe
+        ];
+
+        if (!empty($name)) {
+            $subscriber['Name'] = $name;
+        }
+
+        $subscriber['CustomFields'] = $this->parseCustomFields($customFields);
+
+        if ($mergeMultiFields) {
+            $result = $connection->get($email);
+            
+            $error = null;
+            if (!$this->response($result, $error)) {
+                throw new Exception($error);
+            }
+
+            $existingSubscriber = $result->response;
+
+            foreach ($existingSubscriber->CustomFields as $existingField) {
+                $subscriber['CustomFields'][] = [
+                    'Key' => $existingField->Key,
+                    'Value' => $existingField->Value
+                ];
+            }
+        }
+
+        $result = $connection->update($email, $subscriber);
+
+        $error = null;
+        if (!$this->response($result, $error)) {
+            throw new Exception($error);
+        }
+    }
 }