diff --git a/app/models/signup.rb b/app/models/signup.rb
index 15ac5873c..110c253ef 100644
--- a/app/models/signup.rb
+++ b/app/models/signup.rb
@@ -6,9 +6,8 @@ class Signup
   attr_accessor :full_name, :email_address, :identity
   attr_reader :account, :user
 
-  with_options on: :completion do
-    validates_presence_of :full_name, :identity
-  end
+  validates :email_address, format: { with: URI::MailTo::EMAIL_REGEXP }, on: :identity_creation
+  validates :full_name, :identity, presence: true, on: :completion
 
   def initialize(...)
     super
diff --git a/test/models/signup_test.rb b/test/models/signup_test.rb
index cf7bd3359..589bcd49a 100644
--- a/test/models/signup_test.rb
+++ b/test/models/signup_test.rb
@@ -1,6 +1,15 @@
 require "test_helper"
 
 class SignupTest < ActiveSupport::TestCase
+  test "validates email format for identity creation" do
+    signup = Signup.new(email_address: "not-an-email")
+    assert_not signup.valid?(:identity_creation)
+    assert signup.errors[:email_address].any?
+
+    signup = Signup.new(email_address: "valid@example.com")
+    assert signup.valid?(:identity_creation)
+  end
+
   test "#create_identity" do
     signup = Signup.new(email_address: "brian@example.com")