diff --git a/lib/towerops/accounts/user.ex b/lib/towerops/accounts/user.ex
index d61a819c..7d3341e8 100644
--- a/lib/towerops/accounts/user.ex
+++ b/lib/towerops/accounts/user.ex
@@ -24,7 +24,7 @@ defmodule Towerops.Accounts.User do
     field :authenticated_at, :utc_datetime, virtual: true
     field :is_superuser, :boolean, default: false
     field :name, :string
-    field :timezone, :string
+    field :timezone, :string, default: "UTC"
     field :totp_secret, :binary, redact: true
     field :totp_verified_at, :utc_datetime, virtual: true
     field :privacy_policy_consent, :boolean, virtual: true
@@ -122,7 +122,7 @@ defmodule Towerops.Accounts.User do
   """
   def registration_changeset(user, attrs, opts \\ []) do
     user
-    |> cast(attrs, [:email, :password, :privacy_policy_consent, :terms_of_service_consent])
+    |> cast(attrs, [:email, :password, :timezone, :privacy_policy_consent, :terms_of_service_consent])
     |> validate_email_for_registration(opts)
     |> validate_password(opts)
     |> validate_consent()
diff --git a/test/towerops/accounts_test.exs b/test/towerops/accounts_test.exs
index 7ab57f43..84e576a5 100644
--- a/test/towerops/accounts_test.exs
+++ b/test/towerops/accounts_test.exs
@@ -772,4 +772,33 @@ defmodule Towerops.AccountsTest do
       assert 11 = Accounts.count_unused_recovery_codes(user.id)
     end
   end
+
+  describe "register_user_with_organization/1" do
+    test "accepts timezone in registration params" do
+      valid_attrs = %{
+        "email" => "user@example.com",
+        "password" => "a valid password",
+        "privacy_policy_consent" => true,
+        "terms_of_service_consent" => true,
+        "organization_name" => "Test Org",
+        "timezone" => "America/Chicago"
+      }
+
+      assert {:ok, user} = Accounts.register_user_with_organization(valid_attrs)
+      assert user.timezone == "America/Chicago"
+    end
+
+    test "defaults to UTC when timezone not provided" do
+      valid_attrs = %{
+        "email" => "user@example.com",
+        "password" => "a valid password",
+        "privacy_policy_consent" => true,
+        "terms_of_service_consent" => true,
+        "organization_name" => "Test Org"
+      }
+
+      assert {:ok, user} = Accounts.register_user_with_organization(valid_attrs)
+      assert user.timezone == "UTC"
+    end
+  end
 end