diff --git a/CHANGELOG.md b/CHANGELOG.md
index 13bbca2456..8cd535b1ef 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,6 @@
 ## [v1.2](https://github.com/GEWIS/gewisweb/tree/v1.2) (2017-01-09)
 
+* External participants can now be subscribed to activites through the activity admin
 * Images on committee/fraternity pages now look normal
 * Activities can now be edited :tada: (#594)
 * Improved the activity administrator interface (#642)
diff --git a/module/Activity/Module.php b/module/Activity/Module.php
index a85f094c9f..c582db4add 100644
--- a/module/Activity/Module.php
+++ b/module/Activity/Module.php
@@ -148,14 +148,20 @@ public function getServiceConfig()
                     $acl->addResource('activity_calendar_option');
 
                     $acl->allow('guest', 'activity', 'view');
-                    $acl->allow('guest', 'activitySignup', ['view', 'signup']);
+
+                    $acl->allow('guest', 'activitySignup', ['view', 'externalSignup']);
 
                     $acl->allow('user', 'activity', 'create');
                     $acl->allow('user', 'activitySignup', ['signup', 'signoff', 'checkUserSignedUp']);
 
-                    $acl->allow('admin', 'activity', ['update', 'viewDetails']);
-                    $acl->allow('user', 'activity', ['update', 'viewDetails'], new IsCreator());
-                    $acl->allow('active_member', 'activity', ['update', 'viewDetails'], new IsOrganMember());
+                    $acl->allow('admin', 'activity', ['update', 'viewDetails', 'adminSignup']);
+                    $acl->allow('user', 'activity', ['update', 'viewDetails', 'adminSignup'], new IsCreator());
+                    $acl->allow(
+                        'active_member',
+                        'activity',
+                        ['update', 'viewDetails', 'adminSignup'],
+                        new IsOrganMember()
+                    );
 
                     $acl->allow('sosuser', 'activitySignup', ['signup', 'signoff', 'checkUserSignedUp']);
 
diff --git a/module/Activity/config/module.config.php b/module/Activity/config/module.config.php
index 650ac296db..4ad8993c91 100644
--- a/module/Activity/config/module.config.php
+++ b/module/Activity/config/module.config.php
@@ -107,6 +107,26 @@
                             ]
                         ]
                     ],
+                    'adminSignup' => [
+                        'type' => 'Segment',
+                        'options' => [
+                            'route' => '/:id/adminSignup',
+                            'defaults' => [
+                                'controller' => 'admin',
+                                'action' => 'externalSignup',
+                            ]
+                        ]
+                    ],
+                    'externalSignoff' => [
+                        'type' => 'Segment',
+                        'options' => [
+                            'route' => '/:id/externalSignoff',
+                            'defaults' => [
+                                'controller' => 'admin',
+                                'action' => 'externalSignoff',
+                            ]
+                        ]
+                    ],
                     'exportpdf' => [
                         'type' => 'Segment',
                         'options' => [
diff --git a/module/Activity/src/Activity/Controller/AdminController.php b/module/Activity/src/Activity/Controller/AdminController.php
index 8e607dc9e8..a30c444b76 100644
--- a/module/Activity/src/Activity/Controller/AdminController.php
+++ b/module/Activity/src/Activity/Controller/AdminController.php
@@ -30,7 +30,8 @@ public function participantsAction()
         $queryService = $this->getServiceLocator()->get('activity_service_activityQuery');
         $translatorService = $this->getServiceLocator()->get('activity_service_activityTranslator');
         $langSession = new SessionContainer('lang');
-
+        $translator = $this->getServiceLocator()->get('activity_service_activity')->getTranslator();
+        $signupRequestSession = new SessionContainer('signupRequest');
 
         /** @var $activity Activity */
         $activity = $queryService->getActivityWithDetails($id);
@@ -40,10 +41,23 @@ public function participantsAction()
             return $this->notFoundAction();
         }
 
-        return [
+        $signupService = $this->getServiceLocator()->get('activity_service_signup');
+        $externalSignupForm = $signupService->getExternalForm($activity->getFields());
+
+        $result = [
             'activity' => $translatedActivity,
             'signupData' => $translatorService->getTranslatedSignedUpData($activity, $langSession->lang),
+            'externalSignupForm' => $externalSignupForm,
+            'externalSignoffForm' => new RequestForm('activityExternalSignoff', $translator->translate('Remove')),
         ];
+        //Retrieve and clear the request status from the session, if it exists.
+        if (isset($signupRequestSession->success)) {
+            $result['success'] = $signupRequestSession->success;
+            unset($signupRequestSession->success);
+            $result['message'] = $signupRequestSession->message;
+            unset($signupRequestSession->message);
+        }
+        return $result;
     }
 
     public function updateAction()
@@ -105,6 +119,101 @@ public function exportPdfAction()
         return $pdf;
     }
 
+    public function externalSignupAction()
+    {
+        $id = (int) $this->params('id');
+        $activityService = $this->getServiceLocator()->get('activity_service_activity');
+        $queryService = $this->getServiceLocator()->get('activity_service_activityQuery');
+        $signupService = $this->getServiceLocator()->get('activity_service_signup');
+
+        $activity = $queryService->getActivity($id);
+
+        $translator = $activityService->getTranslator();
+
+        //Assure the form is used
+        if (!$this->getRequest()->isPost()) {
+            $error = $translator->translate('Use the form to subscribe');
+            $this->redirectSignupRequest($id, false, $error);
+            return;
+        }
+
+        $form = $signupService->getExternalForm($activity->getFields());
+        $form->setData($this->getRequest()->getPost());
+
+        //Assure the form is valid
+        if (!$form->isValid()) {
+            $error = $translator->translate('Invalid form');
+            $this->redirectSignupRequest($id, false, $error);
+            return;
+        }
+
+        $formData = $form->getData(\Zend\Form\FormInterface::VALUES_AS_ARRAY);
+        $fullName = $formData['fullName'];
+        unset($formData['fullName']);
+        $email = $formData['email'];
+        unset($formData['email']);
+        $signupService->adminSignUp($activity, $fullName, $email, $formData);
+        $message = $translator->translate('Successfully subscribed external participant');
+        $this->redirectSignupRequest($id, true, $message);
+    }
+
+    public function externalSignoffAction()
+    {
+        $id = (int) $this->params('id');
+
+        $activityService = $this->getServiceLocator()->get('activity_service_activity');
+        $signupService = $this->getServiceLocator()->get('activity_service_signup');
+        $signupMapper = $this->getServiceLocator()->get('activity_mapper_signup');
+
+        $signup = $signupMapper->getSignupById($id);
+
+        if (is_null($signup)) {
+            return $this->notFoundAction();
+        }
+        $activity = $signup->getActivity();
+        $translator = $activityService->getTranslator();
+
+        //Assure a form is used
+        if (!$this->getRequest()->isPost()) {
+            $message = $translator->translate('Use the form to unsubscribe an external participant');
+            $this->redirectSignupRequest($activity->getId(), false, $message);
+            return;
+        }
+
+        $form = new RequestForm('activityExternalSignoff', $translator->translate('Remove'));
+        $form->setData($this->getRequest()->getPost());
+
+        //Assure the form is valid
+        if (!$form->isValid()) {
+            $message = $translator->translate('Invalid form');
+            $this->redirectSignupRequest($activity->getId(), false, $message);
+            return;
+        }
+
+        $signupService->externalSignOff($signup);
+        $message = $translator->translate('Successfully removed external participant');
+        $this->redirectSignupRequest($activity->getId(), true, $message);
+    }
+
+    /**
+     * Redirects to the view of the activity with the given $id, where the
+     * $error message can be displayed if the request was unsuccesful (i.e.
+     * $success was false)
+     *
+     * @param int $id
+     * @param boolean $success Whether the request was successful
+     * @param string $message
+     */
+    protected function redirectSignupRequest($id, $success, $message)
+    {
+        $signupRequestSession = new SessionContainer('signupRequest');
+        $signupRequestSession->success = $success;
+        $signupRequestSession->message = $message;
+        $this->redirect()->toRoute('activity_admin/participants', [
+            'id' => $id,
+        ]);
+    }
+
     /**
      * Show a list of all activities this user can manage.
      */
diff --git a/module/Activity/src/Activity/Form/ActivitySignup.php b/module/Activity/src/Activity/Form/ActivitySignup.php
index 55368131e0..7dcab24475 100644
--- a/module/Activity/src/Activity/Form/ActivitySignup.php
+++ b/module/Activity/src/Activity/Form/ActivitySignup.php
@@ -18,6 +18,11 @@ public function __construct()
         $this->setHydrator(new ClassMethodsHydrator(false))
             ->setObject(new \Activity\Model\UserActivitySignup());
 
+        $this->add([
+            'name' => 'security',
+            'type' => 'Zend\Form\Element\Csrf'
+        ]);
+
         $this->add([
             'name' => 'submit',
             'attributes' => [
@@ -28,18 +33,31 @@ public function __construct()
     }
 
     /**
-     * Initilialise the form, i.e. set the language and the fields
+     * Initialize the form, i.e. set the language and the fields
      * Add every field in $fields to the form.
-     * 
+     *
      * @param ActivityField $fields
      */
     public function initialiseForm($fields)
     {
-        foreach($fields as $field){
+        foreach($fields as $field) {
             $this->add($this->createFieldElementArray($field));
         }
     }
 
+    public function initialiseExternalForm($fields)
+    {
+        $this->add([
+            'name' => 'fullName',
+            'type' => 'Text'
+        ]);
+        $this->add([
+            'name' => 'email',
+            'type' => 'Text'
+        ]);
+        $this->initialiseForm($fields);
+    }
+
     /**
      * Apparently, validators are automatically added, so this works.
      *
diff --git a/module/Activity/src/Activity/Form/ModifyRequest.php b/module/Activity/src/Activity/Form/ModifyRequest.php
index 39e8854c83..cda8719eec 100644
--- a/module/Activity/src/Activity/Form/ModifyRequest.php
+++ b/module/Activity/src/Activity/Form/ModifyRequest.php
@@ -7,7 +7,7 @@
 /**
  * Specifies a form that is used to let an user do a modification request that
  * does not require any other data, such as signing off for activities or
- * approving or dissapproving them.
+ * approving or disapproving them.
  */
 class ModifyRequest extends Form implements InputFilterProviderInterface
 {
diff --git a/module/Activity/src/Activity/Mapper/Signup.php b/module/Activity/src/Activity/Mapper/Signup.php
index e11849b3d9..b487a49944 100644
--- a/module/Activity/src/Activity/Mapper/Signup.php
+++ b/module/Activity/src/Activity/Mapper/Signup.php
@@ -23,6 +23,23 @@ public function __construct(EntityManager $em)
         $this->em = $em;
     }
 
+    /**
+     * @param int $id
+     * @return \Activity\Model\ActivitySignup
+     */
+    public function getSignupById($id)
+    {
+        $qb = $this->em->createQueryBuilder();
+        $qb->select('a')
+            ->from('Activity\Model\ActivitySignup', 'a')
+            ->where('a.id = :id')
+            ->setParameter('id', $id);
+        $result = $qb->getQuery()->getResult();
+
+        return count($result) > 0 ? $result[0] : null;
+    }
+
+
     /**
      * Check if a user is signed up for an activity.
      *
diff --git a/module/Activity/src/Activity/Model/ExternalActivitySignup.php b/module/Activity/src/Activity/Model/ExternalActivitySignup.php
index c48c50771a..7e9dd282a8 100644
--- a/module/Activity/src/Activity/Model/ExternalActivitySignup.php
+++ b/module/Activity/src/Activity/Model/ExternalActivitySignup.php
@@ -44,4 +44,14 @@ public function getEmail()
     {
         return $this->email;
     }
+
+    public function setFullName($fullName)
+    {
+        $this->fullName = $fullName;
+    }
+
+    public function setEmail($email)
+    {
+        $this->email = $email;
+    }
 }
diff --git a/module/Activity/src/Activity/Service/Signup.php b/module/Activity/src/Activity/Service/Signup.php
index 5e4833da7d..ada92a1977 100644
--- a/module/Activity/src/Activity/Service/Signup.php
+++ b/module/Activity/src/Activity/Service/Signup.php
@@ -3,7 +3,9 @@
 namespace Activity\Service;
 
 use Activity\Model\Activity as ActivityModel;
+use Activity\Model\ActivitySignup;
 use Activity\Model\UserActivitySignup;
+use Activity\Model\ExternalActivitySignup;
 use Application\Service\AbstractAclService;
 use Decision\Model\Member;
 
@@ -36,6 +38,7 @@ protected function getDefaultResourceId()
      * Otherwise, it returns it in the available language.
      *
      * @param type $fields
+     * @param bool $external Whether the signup is external.
      * @return type
      * @throws \User\Permissions\NotAllowedException
      */
@@ -52,6 +55,13 @@ public function getForm($fields)
         return $form;
     }
 
+    public function getExternalForm($fields)
+    {
+        $form = new \Activity\Form\ActivitySignup();
+        $form->initialiseExternalForm($fields);
+        return $form;
+    }
+
     /**
      * Get a list of all the members that are signed up for an activity.
      *
@@ -150,7 +160,7 @@ public function getSignedUpActivityIds()
     }
 
     /**
-     * Sign up  an activity with the specified field values.
+     * Sign a User up for an activity with the specified field values.
      *
      * @param ActivityModel $activity
      * @param array $fieldResults
@@ -163,16 +173,82 @@ public function signUp(ActivityModel $activity, array $fieldResults)
                 $translator->translate('You need to be logged in to sign up for this activity')
             );
         }
+        $user = $this->getServiceManager()->get('user_service_user')->getIdentity();
+        $signup = new UserActivitySignup();
+        $signup->setUser($user);
+        $this->createSignup($signup, $activity, $fieldResults);
+    }
 
-        $em = $this->getServiceManager()->get('Doctrine\ORM\EntityManager');
+    /**
+     * Sign an external user up for an activity, which the current user may admin.
+     *
+     * @param \Activity\Service\AcitivityModel $activity
+     * @param type $fullName
+     * @param type $email
+     * @param array $fieldResults
+     * @throws \User\Permissions\NotAllowedException
+     */
+    public function adminSignUp(ActivityModel $activity, $fullName, $email, array $fieldResults)
+    {
+        if (!($this->isAllowed('adminSignup', 'activity') ||
+                $this->isAllowed('adminSignup', $activity))) {
+            $translator = $this->getTranslator();
+            throw new \User\Permissions\NotAllowedException(
+                $translator->translate('You are not allowed to create signups for this activity')
+            );
+        }
+        $this->manualSignUp($activity, $fullName, $email, $fieldResults);
+    }
 
-        // Find the current user
-        $user = $this->getServiceManager()->get('user_service_user')->getIdentity();
+    /**
+     * Sign an external user up for an activity, allowed by a guest.
+     *
+     * @param \Activity\Service\AcitivityModel $activity
+     * @param type $fullName
+     * @param type $email
+     * @param array $fieldResults
+     * @throws \User\Permissions\NotAllowedException
+     */
+    public function externalSignUp(ActivityModel $activity, $fullName, $email, array $fieldResults)
+    {
+        if (!($this->isAllowed('externalSignup', 'activitySignup'))) {
+            $translator = $this->getTranslator();
+            throw new \User\Permissions\NotAllowedException(
+                $translator->translate('You are not allowed to create signups for this activity')
+            );
+        }
+        $this->manualSignUp($activity, $fullName, $email, $fieldResults);
+    }
 
-        $signup = new UserActivitySignup();
+    /**
+     * Sign an external user up for an activity.
+     *
+     * @param \Activity\Service\AcitivityModel $activity
+     * @param type $user
+     * @param array $fieldResults
+     * @throws \User\Permissions\NotAllowedException
+     */
+    protected function manualSignUp(ActivityModel $activity, $fullName, $email, array $fieldResults)
+    {
+        $signup = new ExternalActivitySignup();
+        $signup->setEmail($email);
+        $signup->setFullName($fullName);
+        $this->createSignup($signup, $activity, $fieldResults);
+    }
+
+    /**
+     * Creates the generic parts of a signup.
+     * @param ActivitySignup $signup
+     * @param ActivityModel $activity
+     * @param type $user
+     * @param array $fieldResults
+     * @return ActivitySignup
+     */
+    protected function createSignup(ActivitySignup $signup, ActivityModel $activity, array $fieldResults)
+    {
         $signup->setActivity($activity);
-        $signup->setUser($user);
         $optionMapper = $this->getServiceManager()->get('activity_mapper_activity_option');
+        $em = $this->getServiceManager()->get('Doctrine\ORM\EntityManager');
         foreach ($activity->getFields() as $field){
             $fieldValue = new \Activity\Model\ActivityFieldValue();
             $fieldValue->setField($field);
@@ -196,6 +272,7 @@ public function signUp(ActivityModel $activity, array $fieldResults)
         }
         $em->persist($signup);
         $em->flush();
+        return $signup;
     }
 
     /**
@@ -220,13 +297,25 @@ public function signOff(ActivityModel $activity, Member $user)
         if (is_null($signUp)) {
             return;
         }
+        $this->removeSignUp($signUp);
+    }
 
-        $em = $this->getServiceManager()->get('Doctrine\ORM\EntityManager');
-        $values = $this->getActivityFieldValueMapper()->getFieldValuesBySignup($signUp);
-        foreach($values as $value){
-            $em->remove($value);
+    public function externalSignOff(ExternalActivitySignup $signup)
+    {
+        if (!($this->isAllowed('adminSignup', 'activity') ||
+                $this->isAllowed('adminSignup', $signup->getActivity()))) {
+            $translator = $this->getTranslator();
+            throw new \User\Permissions\NotAllowedException(
+                $translator->translate('You are not allowed to remove external signups for this activity')
+            );
         }
-        $em->remove($signUp);
+        $this->removeSignUp($signup);
+    }
+
+    protected function removeSignUp(ActivitySignup $signup)
+    {
+        $em = $this->getServiceManager()->get('Doctrine\ORM\EntityManager');
+        $em->remove($signup);
         $em->flush();
     }
 
diff --git a/module/Activity/view/activity/activity/view.phtml b/module/Activity/view/activity/activity/view.phtml
index 0528dc03f2..95234fbaa8 100644
--- a/module/Activity/view/activity/activity/view.phtml
+++ b/module/Activity/view/activity/activity/view.phtml
@@ -166,6 +166,7 @@ $this->headTitle($this->translate('Activities')); ?>
         <?php
         $submit = $form->get('submit');
         $submit->setAttribute('class', 'btn btn-primary');
+        echo $this->formElement($form->get('security'));
         echo $this->formSubmit($submit);
         echo $this->form()->closeTag();?>
     <?php endif; ?>
diff --git a/module/Activity/view/activity/admin/participants.phtml b/module/Activity/view/activity/admin/participants.phtml
index b15044dfb4..df2308bee3 100644
--- a/module/Activity/view/activity/admin/participants.phtml
+++ b/module/Activity/view/activity/admin/participants.phtml
@@ -4,12 +4,50 @@
 $this->headTitle($this->escapeHtml($activity->getName()));
 $this->headTitle($this->translate('Participants')); ?>
 
+<?php if (isset($success)): // Display the signup/signoff message. ?>
+    <div class="<?= $success ? 'alert alert-success' : 'alert alert-danger';?>" role="alert">
+        <div class="container">
+            <span class="glyphicon <?= $success ? 'glyphicon-ok' : 'glyphicon-remove';?>"></span>&nbsp;<?= $message ?>
+        </div>
+    </div>
+<?php endif;?>
 
 <div class="container">
     <?= $this->partial('activity/admin/participantsTable.phtml', [
             'activity' => $activity,
-            'signupData' => $signupData
+            'signupData' => $signupData,
+            'externalSignoffForm' => $externalSignoffForm,
     ]);?>
 
     <a href="<?= $this->url('activity_admin/exportpdf', ['id' => $activity->getId()])?>"><?= $this->translate('Download as pdf');?></a>
+
+    <?php if (!is_null($externalSignupForm)): //display the external signup form ?>
+        <?php $externalSignupForm->setAttribute('action', $this->url('activity_admin/adminSignup', ['id' => $activity->getId()]));
+        $externalSignupForm->prepare();
+        echo $this->form()->openTag($externalSignupForm); ?>
+            <table>
+                <tr>
+                    <td><?= $this->translate('Full name:'); ?></td>
+                    <td><?= $this->formRow($externalSignupForm->get('fullName')) ?></td>
+                </tr>
+                <tr>
+                    <td><?= $this->translate('Email address:'); ?></td>
+                    <td><?= $this->formRow($externalSignupForm->get('email')) ?></td>
+                </tr>
+                <?php foreach($activity->getFields() as $field):?>
+                <tr>
+                    <td><?= $this->escapeHtml($field->getName()) ?>:</td>
+                    <td><?= $this->formRow($externalSignupForm->get($field->getId())) ?></td>
+                </tr>
+                <?php endforeach;?>
+            </table>
+        <?php
+        $submit = $externalSignupForm->get('submit');
+        $submit->setAttribute('class', 'btn btn-primary');
+        $submit->setAttribute('value', $this->translate('Subscribe external participant'));
+        echo $this->formElement($externalSignupForm->get('security'));
+        echo $this->formSubmit($submit);
+        echo $this->form()->closeTag();?>
+    <?php endif; ?>
+
 </div>
diff --git a/module/Activity/view/activity/admin/participantsTable.phtml b/module/Activity/view/activity/admin/participantsTable.phtml
index 0ef6342ebf..a17a660e10 100644
--- a/module/Activity/view/activity/admin/participantsTable.phtml
+++ b/module/Activity/view/activity/admin/participantsTable.phtml
@@ -5,6 +5,7 @@
             <th></th>
             <th><?= $this->translate('Name') ?></th>
             <th><?= $this->translate('Email') ?></th>
+            <th><?= $this->translate('Type') ?></th>
             <?php foreach ($activity->getFields() as $field): ?>
                 <th><?= $this->escapeHtml($field->getName()) ?></th>
             <?php endforeach; ?>
@@ -20,6 +21,22 @@
                     <?= $email ?>
                 </a>
             </td>
+            <?php if ($signup instanceof Activity\Model\UserActivitySignup): ?>
+            <td><?= $this->translate('User')?></td>
+            <?php else: ?>
+            <td>
+                <?= $this->translate('External')?>
+                <?php $externalSignoffForm->setAttribute('action', $this->url('activity_admin/externalSignoff', ['id' => $signup->getId()]));
+                $externalSignoffForm->prepare();
+                echo $this->form()->openTag($externalSignoffForm);
+                echo $this->formElement($externalSignoffForm->get('security'));
+                $submit = $externalSignoffForm->get('submit');
+                $submit->setAttribute('class', 'btn btn-primary btn-xs');
+                echo $this->formSubmit($submit);
+                echo $this->form()->closeTag();
+                ?>
+            </td>
+            <?php endif; ?>
             <?php foreach ($activity->getFields() as $field): ?>
                 <?php foreach($signup->getFieldValues() as $fieldValue):?>
                     <?php if ($fieldValue->getField()->getId() === $field->getId()): ?>
@@ -64,6 +81,7 @@
                 <?= $this->translate('Mail everybody') ?>
             </a>
         </td>
+        <td></td>
         <?php foreach ($activity->getFields() as $field): ?>
             <td></td>
         <?php endforeach; ?>