diff --git a/FirebaseAuthUI/FUIAuth.h b/FirebaseAuthUI/FUIAuth.h
index 8fa95b3ff2a..6dda18424fd 100644
--- a/FirebaseAuthUI/FUIAuth.h
+++ b/FirebaseAuthUI/FUIAuth.h
@@ -176,6 +176,11 @@ __attribute__((deprecated("Instead use authUI:didSignInWithAuthDataResult:error:
  */
 @property(nonatomic, assign, getter=isSignInWithEmailHidden) BOOL signInWithEmailHidden;
 
+/** @property allowNewEmailAccounts
+ @brief Whether to allow new user sign, defaults to YES.
+ */
+@property(nonatomic, assign) BOOL allowNewEmailAccounts;
+
 /** @property customStringsBundle
     @brief Custom strings bundle supplied by the developer. Nil when there is no custom strings
         bundle set. In which case the default bundle will be used.
diff --git a/FirebaseAuthUI/FUIAuth.m b/FirebaseAuthUI/FUIAuth.m
index d73700a19d5..c0b8cb85bda 100644
--- a/FirebaseAuthUI/FUIAuth.m
+++ b/FirebaseAuthUI/FUIAuth.m
@@ -27,6 +27,7 @@
 #import "FUIAuthStrings.h"
 #import "FUIEmailEntryViewController.h"
 #import "FUIPasswordVerificationViewController.h"
+#import "FUIPasswordSignInViewController.h"
 
 /** @var kAppNameCodingKey
     @brief The key used to encode the app Name for NSCoding.
@@ -104,6 +105,7 @@ + (nullable FUIAuth *)authUIWithAuth:(FIRAuth *)auth {
 - (instancetype)initWithAuth:(FIRAuth *)auth {
   self = [super init];
   if (self) {
+    _allowNewEmailAccounts = YES;
     _auth = auth;
   }
   return self;
@@ -125,11 +127,20 @@ - (UINavigationController *)authViewController {
   UIViewController *controller;
 
   if (self.providers.count == 0 && !self.isSignInWithEmailHidden) {
-    if ([self.delegate respondsToSelector:@selector(emailEntryViewControllerForAuthUI:)]) {
-      controller = [self.delegate emailEntryViewControllerForAuthUI:self];
-    } else {
-      controller = [[FUIEmailEntryViewController alloc] initWithAuthUI:self];
-    }
+      if (self.allowNewEmailAccounts) {
+        if ([self.delegate respondsToSelector:@selector(emailEntryViewControllerForAuthUI:)]) {
+          controller = [self.delegate emailEntryViewControllerForAuthUI:self];
+        } else {
+          controller = [[FUIEmailEntryViewController alloc] initWithAuthUI:self];
+        }
+      }
+      else {
+        if ([self.delegate respondsToSelector:@selector(emailEntryViewControllerForAuthUI:)]) {
+            controller = [self.delegate passwordSignInViewControllerForAuthUI:self email:@""];
+        } else {
+            controller = [[FUIPasswordSignInViewController alloc] initWithAuthUI:self email:nil];
+        }
+      }
   } else if ([self.delegate respondsToSelector:@selector(authPickerViewControllerForAuthUI:)]) {
     controller = [self.delegate authPickerViewControllerForAuthUI:self];
   } else {
diff --git a/FirebaseAuthUI/FUIEmailEntryViewController.m b/FirebaseAuthUI/FUIEmailEntryViewController.m
index d115e1efca3..883e06ad0f5 100644
--- a/FirebaseAuthUI/FUIEmailEntryViewController.m
+++ b/FirebaseAuthUI/FUIEmailEntryViewController.m
@@ -174,12 +174,16 @@ - (void)onNext:(NSString *)emailText {
       } else {
         // New user.
         UIViewController *controller;
-        if ([self.authUI.delegate respondsToSelector:@selector(passwordSignUpViewControllerForAuthUI:email:)]) {
-          controller = [self.authUI.delegate passwordSignUpViewControllerForAuthUI:self.authUI
+        if (self.authUI.allowNewEmailAccounts) {
+          if ([self.authUI.delegate respondsToSelector:@selector(passwordSignUpViewControllerForAuthUI:email:)]) {
+            controller = [self.authUI.delegate passwordSignUpViewControllerForAuthUI:self.authUI
                                                                              email:emailText];
-        } else {
-          controller = [[FUIPasswordSignUpViewController alloc] initWithAuthUI:self.authUI
+          } else {
+            controller = [[FUIPasswordSignUpViewController alloc] initWithAuthUI:self.authUI
                                                                          email:emailText];
+          }
+        } else {
+            [self showAlertWithMessage:FUILocalizedString(kStr_UserNotFoundError)];
         }
         [self pushViewController:controller];
       }
diff --git a/FirebaseAuthUI/FUIPasswordSignInViewController.m b/FirebaseAuthUI/FUIPasswordSignInViewController.m
index 7e8d6525217..e080e00144e 100644
--- a/FirebaseAuthUI/FUIPasswordSignInViewController.m
+++ b/FirebaseAuthUI/FUIPasswordSignInViewController.m
@@ -95,6 +95,23 @@ - (void)viewDidLoad {
   [self enableDynamicCellHeightForTableView:_tableView];
 }
 
+- (void)viewWillAppear:(BOOL)animated {
+    [super viewWillAppear:animated];
+    
+    if (self.navigationController.viewControllers.firstObject == self) {
+        UIBarButtonItem *cancelBarButton =
+        [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemCancel
+                                                      target:self
+                                                      action:@selector(cancelAuthorization)];
+        self.navigationItem.leftBarButtonItem = cancelBarButton;
+        self.navigationItem.backBarButtonItem =
+        [[UIBarButtonItem alloc] initWithTitle:FUILocalizedString(kStr_Back)
+                                         style:UIBarButtonItemStylePlain
+                                        target:nil
+                                        action:nil];
+    }
+}
+
 #pragma mark - Actions
 
 - (void)signInWithDefaultValue:(NSString *)email andPassword:(NSString *)password {