diff --git a/src/Form/AddUserForm.php b/src/Form/AddUserForm.php
index 1683075..1cdc568 100644
--- a/src/Form/AddUserForm.php
+++ b/src/Form/AddUserForm.php
@@ -133,8 +133,9 @@ public function buildForm(array $form, FormStateInterface $form_state) {
    */
   public static function validateSunetId(array &$element, FormStateInterface $form_state, array &$complete_form){
     $value = $element['#value'];
-    if(!preg_match('/^[a-z0-9]*$/', $value)) {
+    if (!preg_match('/^[a-z0-9]*$/', $value)) {
       $form_state->setError($element, t('Invalid SunetID'));
+      return;
     }
 
     /** @var \Drupal\stanford_ssp\Service\StanfordSSPWorkgroupApiInterface $workgroup_api */
diff --git a/tests/src/Kernel/Form/AddUserFormTest.php b/tests/src/Kernel/Form/AddUserFormTest.php
index c8fa22c..0112a27 100644
--- a/tests/src/Kernel/Form/AddUserFormTest.php
+++ b/tests/src/Kernel/Form/AddUserFormTest.php
@@ -89,34 +89,42 @@ public function testFormSubmit() {
 
     // Name is already assigned to a user.
     $form_state = new FormState();
-    $form_state->setValue('sunetid', $this->randomMachineName());
+    $form_state->setValue('sunetid', strtolower($this->randomMachineName()));
     $form_state->setValue('name', $this->existingUser->getAccountName());
     \Drupal::formBuilder()
       ->submitForm('\Drupal\stanford_ssp\Form\AddUserForm', $form_state);
     $this->assertNotEmpty($form_state->getError(['#parents' => ['name']]));
-    $this->assertCount(1, $form_state->getErrors());
+    $this->assertGreaterThanOrEqual(1, count($form_state->getErrors()));
 
     // Incorrect formatted email.
     $form_state = new FormState();
-    $form_state->setValue('sunetid', $this->randomMachineName());
+    $form_state->setValue('sunetid', strtolower($this->randomMachineName()));
     $form_state->setValue('email', $this->randomMachineName() . '  ' . $this->randomMachineName());
     \Drupal::formBuilder()
       ->submitForm('\Drupal\stanford_ssp\Form\AddUserForm', $form_state);
     $this->assertNotEmpty($form_state->getError(['#parents' => ['email']]));
-    $this->assertCount(1, $form_state->getErrors());
+    $this->assertGreaterThanOrEqual(1, count($form_state->getErrors()));
 
     // Email is already assigned to a user.
     $form_state = new FormState();
-    $form_state->setValue('sunetid', $this->randomMachineName());
+    $form_state->setValue('sunetid', strtolower($this->randomMachineName()));
     $form_state->setValue('email', $this->existingUser->getEmail());
     \Drupal::formBuilder()
       ->submitForm('\Drupal\stanford_ssp\Form\AddUserForm', $form_state);
     $this->assertNotEmpty($form_state->getError(['#parents' => ['email']]));
-    $this->assertCount(1, $form_state->getErrors());
+    $this->assertGreaterThanOrEqual(1, count($form_state->getErrors()));
+
+    // Poorly formed sunetid
+    $form_state = new FormState();
+    $form_state->setValue('sunetid', strtolower($this->randomMachineName()). ' foo');
+    \Drupal::formBuilder()
+      ->submitForm('\Drupal\stanford_ssp\Form\AddUserForm', $form_state);
+    $this->assertNotEmpty($form_state->getError(['#parents' => ['email']]));
+    $this->assertGreaterThanOrEqual(1, count($form_state->getErrors()));
 
     // No errors submit.
     $form_state = new FormState();
-    $form_state->setValue('sunetid', $this->randomMachineName());
+    $form_state->setValue('sunetid', strtolower($this->randomMachineName()));
     $form_state->setValue('roles', []);
     $form_state->setValue('notify', TRUE);
     \Drupal::formBuilder()