diff --git a/lib/accounts/accounts.ex b/lib/accounts/accounts.ex
index 7bc5073..a96b5ac 100644
--- a/lib/accounts/accounts.ex
+++ b/lib/accounts/accounts.ex
@@ -21,4 +21,15 @@ defmodule Mv.Accounts do
 
     resource Mv.Accounts.Token
   end
+
+  @doc """
+  Register a new user with password using AshAuthentication's standard action.
+  This creates a user and the notifier will automatically create a member.
+  """
+  def register_with_password(params) do
+    # Use AshAuthentication's standard register_with_password action
+    Mv.Accounts.User
+    |> Ash.Changeset.for_create(:register_with_password, params)
+    |> Ash.create(domain: __MODULE__)
+  end
 end
diff --git a/lib/accounts/user.ex b/lib/accounts/user.ex
index d8c7a66..7163649 100644
--- a/lib/accounts/user.ex
+++ b/lib/accounts/user.ex
@@ -5,7 +5,8 @@ defmodule Mv.Accounts.User do
   use Ash.Resource,
     domain: Mv.Accounts,
     data_layer: AshPostgres.DataLayer,
-    extensions: [AshAuthentication]
+    extensions: [AshAuthentication],
+    notifiers: [Mv.Accounts.User.MemberCreationNotifier]
 
   # authorizers: [Ash.Policy.Authorizer]
 
@@ -64,11 +65,16 @@ defmodule Mv.Accounts.User do
     defaults [:read, :create, :destroy, :update]
 
     create :create_user do
-      accept [:email]
+      accept [:email, :member_id]
+      argument :member, :map
+      change manage_relationship(:member, type: :create)
     end
 
     update :update_user do
-      accept [:email]
+      require_atomic? false
+      accept [:email, :member_id]
+      argument :member, :map
+      change manage_relationship(:member, on_match: :update, on_no_match: :create)
     end
 
     # Admin action for direct password changes in admin panel
@@ -152,6 +158,7 @@ defmodule Mv.Accounts.User do
   identities do
     identity :unique_email, [:email]
     identity :unique_oidc_id, [:oidc_id]
+    identity :unique_member_id, [:member_id]
   end
 
   # You can customize this if you wish, but this is a safe default that
diff --git a/lib/accounts/user/member_creation_notifier.ex b/lib/accounts/user/member_creation_notifier.ex
new file mode 100644
index 0000000..9cc6ef8
--- /dev/null
+++ b/lib/accounts/user/member_creation_notifier.ex
@@ -0,0 +1,41 @@
+defmodule Mv.Accounts.User.MemberCreationNotifier do
+  @moduledoc """
+  Notifier that automatically creates a member for users who don't have one.
+  This ensures that every user has an associated member profile.
+  """
+
+  use Ash.Notifier
+
+  def notify(%Ash.Notifier.Notification{
+        action: %{name: action_name},
+        resource: Mv.Accounts.User,
+        data: user
+      })
+      when action_name in [:create_user, :register_with_password] do
+    # Only create member if user doesn't have one
+    if is_nil(user.member_id) do
+      create_member_for_user(user)
+    else
+      :ok
+    end
+  end
+
+  def notify(_), do: :ok
+
+  defp create_member_for_user(user) do
+    member_attrs = %{
+      member_email: user.email
+    }
+
+    case Mv.Membership.create_member(member_attrs) do
+      {:ok, member} ->
+        # Update the user with the new member_id
+        Mv.Accounts.update_user(user, %{member_id: member.id})
+
+      {:error, _error} ->
+        # Log error but don't fail the user creation
+        # In a real application, you might want to handle this differently
+        :ok
+    end
+  end
+end
diff --git a/lib/membership/member.ex b/lib/membership/member.ex
index 583f173..1ac0f0f 100644
--- a/lib/membership/member.ex
+++ b/lib/membership/member.ex
@@ -18,7 +18,7 @@ defmodule Mv.Membership.Member do
       accept [
         :first_name,
         :last_name,
-        :email,
+        :member_email,
         :birth_date,
         :paid,
         :phone_number,
@@ -42,7 +42,7 @@ defmodule Mv.Membership.Member do
       accept [
         :first_name,
         :last_name,
-        :email,
+        :member_email,
         :birth_date,
         :paid,
         :phone_number,
@@ -60,12 +60,7 @@ defmodule Mv.Membership.Member do
   end
 
   validations do
-    # Required fields are covered by allow_nil? false
-
-    # First name and last name must not be empty
-    validate present(:first_name)
-    validate present(:last_name)
-    validate present(:email)
+    # All fields are optional - no required validations
 
     # Birth date not in the future
     validate compare(:birth_date, less_than_or_equal_to: &Date.utc_today/0),
@@ -92,38 +87,38 @@ defmodule Mv.Membership.Member do
       where: [present(:postal_code)],
       message: "must consist of 5 digits"
 
-    # Email validation with EctoCommons.EmailValidator
+    # Email validation with EctoCommons.EmailValidator (only for member_email)
     validate fn changeset, _ ->
-      email = Ash.Changeset.get_attribute(changeset, :email)
+               member_email = Ash.Changeset.get_attribute(changeset, :member_email)
 
-      changeset2 =
-        {%{}, %{email: :string}}
-        |> Ecto.Changeset.cast(%{email: email}, [:email])
-        |> EctoCommons.EmailValidator.validate_email(:email, checks: [:html_input, :pow])
+               changeset2 =
+                 {%{}, %{email: :string}}
+                 |> Ecto.Changeset.cast(%{email: member_email}, [:email])
+                 |> EctoCommons.EmailValidator.validate_email(:email, checks: [:html_input, :pow])
 
-      if changeset2.valid? do
-        :ok
-      else
-        {:error, field: :email, message: "is not a valid email"}
-      end
-    end
+               if changeset2.valid? do
+                 :ok
+               else
+                 {:error, field: :member_email, message: "is not a valid email"}
+               end
+             end,
+             where: [present(:member_email)]
   end
 
   attributes do
     uuid_v7_primary_key :id
 
     attribute :first_name, :string do
-      allow_nil? false
-      constraints min_length: 1
+      allow_nil? true
     end
 
     attribute :last_name, :string do
-      allow_nil? false
-      constraints min_length: 1
+      allow_nil? true
     end
 
-    attribute :email, :string do
-      allow_nil? false
+    # Internal email field for members without users
+    attribute :member_email, :string do
+      allow_nil? true
       constraints min_length: 5, max_length: 254
     end
 
@@ -170,5 +165,10 @@ defmodule Mv.Membership.Member do
 
   relationships do
     has_many :properties, Mv.Membership.Property
+    has_one :user, Mv.Accounts.User, destination_attribute: :member_id
+  end
+
+  calculations do
+    calculate :email, :string, Mv.Membership.MemberEmailCalculation
   end
 end
diff --git a/lib/membership/member_email_calculation.ex b/lib/membership/member_email_calculation.ex
new file mode 100644
index 0000000..0f577d2
--- /dev/null
+++ b/lib/membership/member_email_calculation.ex
@@ -0,0 +1,27 @@
+defmodule Mv.Membership.MemberEmailCalculation do
+  use Ash.Resource.Calculation
+
+  @impl true
+  def load(_query, _opts, _context) do
+    # We need member_email and user.email
+    [:member_email, user: [:email]]
+  end
+
+  @impl true
+  def calculate(records, _opts, _context) do
+    Enum.map(records, fn record ->
+      case record.user do
+        %{email: user_email} ->
+          # Convert Ash.CiString to string if needed
+          if is_struct(user_email, Ash.CiString) do
+            to_string(user_email)
+          else
+            user_email
+          end
+
+        _ ->
+          record.member_email
+      end
+    end)
+  end
+end
diff --git a/lib/membership/membership.ex b/lib/membership/membership.ex
index 0c7c14d..afed432 100644
--- a/lib/membership/membership.ex
+++ b/lib/membership/membership.ex
@@ -10,6 +10,7 @@ defmodule Mv.Membership do
     resource Mv.Membership.Member do
       define :create_member, action: :create_member
       define :list_members, action: :read
+      define :get_member!, action: :read, get_by: [:id]
       define :update_member, action: :update_member
       define :destroy_member, action: :destroy
     end
diff --git a/mix.lock b/mix.lock
index 2060db6..4392c65 100644
--- a/mix.lock
+++ b/mix.lock
@@ -60,7 +60,7 @@
   "phoenix_view": {:hex, :phoenix_view, "2.0.4", "b45c9d9cf15b3a1af5fb555c674b525391b6a1fe975f040fb4d913397b31abf4", [:mix], [{:phoenix_html, "~> 2.14.2 or ~> 3.0 or ~> 4.0", [hex: :phoenix_html, repo: "hexpm", optional: true]}, {:phoenix_template, "~> 1.0", [hex: :phoenix_template, repo: "hexpm", optional: false]}], "hexpm", "4e992022ce14f31fe57335db27a28154afcc94e9983266835bb3040243eb620b"},
   "plug": {:hex, :plug, "1.18.1", "5067f26f7745b7e31bc3368bc1a2b818b9779faa959b49c934c17730efc911cf", [:mix], [{:mime, "~> 1.0 or ~> 2.0", [hex: :mime, repo: "hexpm", optional: false]}, {:plug_crypto, "~> 1.1.1 or ~> 1.2 or ~> 2.0", [hex: :plug_crypto, repo: "hexpm", optional: false]}, {:telemetry, "~> 0.4.3 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "57a57db70df2b422b564437d2d33cf8d33cd16339c1edb190cd11b1a3a546cc2"},
   "plug_crypto": {:hex, :plug_crypto, "2.1.1", "19bda8184399cb24afa10be734f84a16ea0a2bc65054e23a62bb10f06bc89491", [:mix], [], "hexpm", "6470bce6ffe41c8bd497612ffde1a7e4af67f36a15eea5f921af71cf3e11247c"},
-  "postgrex": {:hex, :postgrex, "0.20.0", "363ed03ab4757f6bc47942eff7720640795eb557e1935951c1626f0d303a3aed", [:mix], [{:db_connection, "~> 2.1", [hex: :db_connection, repo: "hexpm", optional: false]}, {:decimal, "~> 1.5 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}, {:table, "~> 0.1.0", [hex: :table, repo: "hexpm", optional: true]}], "hexpm", "d36ef8b36f323d29505314f704e21a1a038e2dc387c6409ee0cd24144e187c0f"},
+  "postgrex": {:hex, :postgrex, "0.21.1", "2c5cc830ec11e7a0067dd4d623c049b3ef807e9507a424985b8dcf921224cd88", [:mix], [{:db_connection, "~> 2.1", [hex: :db_connection, repo: "hexpm", optional: false]}, {:decimal, "~> 1.5 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}, {:table, "~> 0.1.0", [hex: :table, repo: "hexpm", optional: true]}], "hexpm", "27d8d21c103c3cc68851b533ff99eef353e6a0ff98dc444ea751de43eb48bdac"},
   "reactor": {:hex, :reactor, "0.15.6", "d717f9add549b25a089a94c90197718d2d838e35d81dd776b1d81587d4cf2aaa", [:mix], [{:igniter, "~> 0.4", [hex: :igniter, repo: "hexpm", optional: true]}, {:iterex, "~> 0.1", [hex: :iterex, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}, {:libgraph, "~> 0.16", [hex: :libgraph, repo: "hexpm", optional: false]}, {:spark, "~> 2.0", [hex: :spark, repo: "hexpm", optional: false]}, {:splode, "~> 0.2", [hex: :splode, repo: "hexpm", optional: false]}, {:telemetry, "~> 1.2", [hex: :telemetry, repo: "hexpm", optional: false]}, {:yaml_elixir, "~> 2.11", [hex: :yaml_elixir, repo: "hexpm", optional: false]}, {:ymlr, "~> 5.0", [hex: :ymlr, repo: "hexpm", optional: false]}], "hexpm", "74db98165e3644d86e0f723672d91ceca4339eaa935bcad7e78bf146a46d77b9"},
   "req": {:hex, :req, "0.5.15", "662020efb6ea60b9f0e0fac9be88cd7558b53fe51155a2d9899de594f9906ba9", [:mix], [{:brotli, "~> 0.3.1", [hex: :brotli, repo: "hexpm", optional: true]}, {:ezstd, "~> 1.0", [hex: :ezstd, repo: "hexpm", optional: true]}, {:finch, "~> 0.17", [hex: :finch, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}, {:mime, "~> 2.0.6 or ~> 2.1", [hex: :mime, repo: "hexpm", optional: false]}, {:nimble_csv, "~> 1.0", [hex: :nimble_csv, repo: "hexpm", optional: true]}, {:plug, "~> 1.0", [hex: :plug, repo: "hexpm", optional: true]}], "hexpm", "a6513a35fad65467893ced9785457e91693352c70b58bbc045b47e5eb2ef0c53"},
   "rewrite": {:hex, :rewrite, "1.1.2", "f5a5d10f5fed1491a6ff48e078d4585882695962ccc9e6c779bae025d1f92eda", [:mix], [{:glob_ex, "~> 0.1", [hex: :glob_ex, repo: "hexpm", optional: false]}, {:sourceror, "~> 1.0", [hex: :sourceror, repo: "hexpm", optional: false]}, {:text_diff, "~> 0.1", [hex: :text_diff, repo: "hexpm", optional: false]}], "hexpm", "7f8b94b1e3528d0a47b3e8b7bfeca559d2948a65fa7418a9ad7d7712703d39d4"},
diff --git a/priv/repo/migrations/20250724161006_add_unique_member_id.exs b/priv/repo/migrations/20250724161006_add_unique_member_id.exs
new file mode 100644
index 0000000..973b957
--- /dev/null
+++ b/priv/repo/migrations/20250724161006_add_unique_member_id.exs
@@ -0,0 +1,17 @@
+defmodule Mv.Repo.Migrations.AddUniqueMemberId do
+  @moduledoc """
+  Updates resources based on their most recent snapshots.
+
+  This file was autogenerated with `mix ash_postgres.generate_migrations`
+  """
+
+  use Ecto.Migration
+
+  def up do
+    create unique_index(:users, [:member_id], name: "users_unique_member_id_index")
+  end
+
+  def down do
+    drop_if_exists unique_index(:users, [:member_id], name: "users_unique_member_id_index")
+  end
+end
diff --git a/priv/repo/migrations/20250805131958_add_member_email_to_members.exs b/priv/repo/migrations/20250805131958_add_member_email_to_members.exs
new file mode 100644
index 0000000..24ce69b
--- /dev/null
+++ b/priv/repo/migrations/20250805131958_add_member_email_to_members.exs
@@ -0,0 +1,25 @@
+defmodule Mv.Repo.Migrations.AddMemberEmailToMembers do
+  @moduledoc """
+  Updates resources based on their most recent snapshots.
+
+  This file was autogenerated with `mix ash_postgres.generate_migrations`
+  """
+
+  use Ecto.Migration
+
+  def up do
+    rename table(:members), :email, to: :member_email
+
+    alter table(:members) do
+      modify :member_email, :text, null: true
+    end
+  end
+
+  def down do
+    alter table(:members) do
+      modify :email, :text, null: false
+    end
+
+    rename table(:members), :member_email, to: :email
+  end
+end
diff --git a/priv/repo/migrations/20250805151226_update_member_constraints.exs b/priv/repo/migrations/20250805151226_update_member_constraints.exs
new file mode 100644
index 0000000..ec123ca
--- /dev/null
+++ b/priv/repo/migrations/20250805151226_update_member_constraints.exs
@@ -0,0 +1,23 @@
+defmodule Mv.Repo.Migrations.UpdateMemberConstraints do
+  @moduledoc """
+  Updates resources based on their most recent snapshots.
+
+  This file was autogenerated with `mix ash_postgres.generate_migrations`
+  """
+
+  use Ecto.Migration
+
+  def up do
+    alter table(:members) do
+      modify :last_name, :text, null: true
+      modify :first_name, :text, null: true
+    end
+  end
+
+  def down do
+    alter table(:members) do
+      modify :first_name, :text, null: false
+      modify :last_name, :text, null: false
+    end
+  end
+end
diff --git a/priv/resource_snapshots/repo/members/20250805131958.json b/priv/resource_snapshots/repo/members/20250805131958.json
new file mode 100644
index 0000000..86cc148
--- /dev/null
+++ b/priv/resource_snapshots/repo/members/20250805131958.json
@@ -0,0 +1,187 @@
+{
+  "attributes": [
+    {
+      "allow_nil?": false,
+      "default": "fragment(\"uuid_generate_v7()\")",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": true,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "id",
+      "type": "uuid"
+    },
+    {
+      "allow_nil?": false,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "first_name",
+      "type": "text"
+    },
+    {
+      "allow_nil?": false,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "last_name",
+      "type": "text"
+    },
+    {
+      "allow_nil?": true,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "member_email",
+      "type": "text"
+    },
+    {
+      "allow_nil?": true,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "birth_date",
+      "type": "date"
+    },
+    {
+      "allow_nil?": true,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "paid",
+      "type": "boolean"
+    },
+    {
+      "allow_nil?": true,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "phone_number",
+      "type": "text"
+    },
+    {
+      "allow_nil?": true,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "join_date",
+      "type": "date"
+    },
+    {
+      "allow_nil?": true,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "exit_date",
+      "type": "date"
+    },
+    {
+      "allow_nil?": true,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "notes",
+      "type": "text"
+    },
+    {
+      "allow_nil?": true,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "city",
+      "type": "text"
+    },
+    {
+      "allow_nil?": true,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "street",
+      "type": "text"
+    },
+    {
+      "allow_nil?": true,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "house_number",
+      "type": "text"
+    },
+    {
+      "allow_nil?": true,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "postal_code",
+      "type": "text"
+    }
+  ],
+  "base_filter": null,
+  "check_constraints": [],
+  "custom_indexes": [],
+  "custom_statements": [],
+  "has_create_action": true,
+  "hash": "F783CF3A9A24DD4D635BD2820236F3DB9A95F7FA6EBA94A3C15A3F054D579999",
+  "identities": [],
+  "multitenancy": {
+    "attribute": null,
+    "global": null,
+    "strategy": null
+  },
+  "repo": "Elixir.Mv.Repo",
+  "schema": null,
+  "table": "members"
+}
\ No newline at end of file
diff --git a/priv/resource_snapshots/repo/members/20250805151226.json b/priv/resource_snapshots/repo/members/20250805151226.json
new file mode 100644
index 0000000..563f3b6
--- /dev/null
+++ b/priv/resource_snapshots/repo/members/20250805151226.json
@@ -0,0 +1,187 @@
+{
+  "attributes": [
+    {
+      "allow_nil?": false,
+      "default": "fragment(\"uuid_generate_v7()\")",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": true,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "id",
+      "type": "uuid"
+    },
+    {
+      "allow_nil?": true,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "first_name",
+      "type": "text"
+    },
+    {
+      "allow_nil?": true,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "last_name",
+      "type": "text"
+    },
+    {
+      "allow_nil?": true,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "member_email",
+      "type": "text"
+    },
+    {
+      "allow_nil?": true,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "birth_date",
+      "type": "date"
+    },
+    {
+      "allow_nil?": true,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "paid",
+      "type": "boolean"
+    },
+    {
+      "allow_nil?": true,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "phone_number",
+      "type": "text"
+    },
+    {
+      "allow_nil?": true,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "join_date",
+      "type": "date"
+    },
+    {
+      "allow_nil?": true,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "exit_date",
+      "type": "date"
+    },
+    {
+      "allow_nil?": true,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "notes",
+      "type": "text"
+    },
+    {
+      "allow_nil?": true,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "city",
+      "type": "text"
+    },
+    {
+      "allow_nil?": true,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "street",
+      "type": "text"
+    },
+    {
+      "allow_nil?": true,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "house_number",
+      "type": "text"
+    },
+    {
+      "allow_nil?": true,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "postal_code",
+      "type": "text"
+    }
+  ],
+  "base_filter": null,
+  "check_constraints": [],
+  "custom_indexes": [],
+  "custom_statements": [],
+  "has_create_action": true,
+  "hash": "A287EF28CB6E052DB408E8045D54E43CED1252820DD43D261E26E1DDF5CA7966",
+  "identities": [],
+  "multitenancy": {
+    "attribute": null,
+    "global": null,
+    "strategy": null
+  },
+  "repo": "Elixir.Mv.Repo",
+  "schema": null,
+  "table": "members"
+}
\ No newline at end of file
diff --git a/test/accounts/empty_member_creation_test.exs b/test/accounts/empty_member_creation_test.exs
new file mode 100644
index 0000000..8044354
--- /dev/null
+++ b/test/accounts/empty_member_creation_test.exs
@@ -0,0 +1,52 @@
+defmodule Mv.Accounts.EmptyMemberCreationTest do
+  use Mv.DataCase, async: true
+  alias Mv.Accounts
+  alias Mv.Membership
+
+  describe "Empty Member Creation" do
+    test "can create completely empty member" do
+      {:ok, member} = Membership.create_member(%{})
+
+      assert member.id
+      assert member.first_name == nil
+      assert member.last_name == nil
+      assert member.member_email == nil
+      assert member.birth_date == nil
+      assert member.paid == nil
+      assert member.phone_number == nil
+      assert member.join_date == nil
+      assert member.exit_date == nil
+      assert member.notes == nil
+      assert member.city == nil
+      assert member.street == nil
+      assert member.house_number == nil
+      assert member.postal_code == nil
+    end
+
+    test "user creation creates empty member automatically" do
+      {:ok, user} = Accounts.create_user(%{email: "test@example.com"})
+
+      # Reload user to get the member_id
+      user = Ash.reload!(user, domain: Mv.Accounts)
+      assert user.member_id
+
+      # Get the created member
+      member = Ash.get!(Mv.Membership.Member, user.member_id, domain: Mv.Membership)
+
+      # Member should be mostly empty except for email
+      assert member.member_email == "test@example.com"
+      assert member.first_name == nil
+      assert member.last_name == nil
+      assert member.birth_date == nil
+      assert member.paid == nil
+      assert member.phone_number == nil
+      assert member.join_date == nil
+      assert member.exit_date == nil
+      assert member.notes == nil
+      assert member.city == nil
+      assert member.street == nil
+      assert member.house_number == nil
+      assert member.postal_code == nil
+    end
+  end
+end
diff --git a/test/accounts/password_email_identification_test.exs b/test/accounts/password_email_identification_test.exs
new file mode 100644
index 0000000..db93187
--- /dev/null
+++ b/test/accounts/password_email_identification_test.exs
@@ -0,0 +1,80 @@
+defmodule Mv.Accounts.PasswordEmailIdentificationTest do
+  use Mv.DataCase, async: true
+
+  describe "Password Email Identification" do
+    test "user can sign in with email and password" do
+      # Get the password strategy
+      strategy = AshAuthentication.Info.strategy!(Mv.Accounts.User, :password)
+
+      # Create a user with password
+      {:ok, user} =
+        AshAuthentication.Strategy.action(strategy, :register, %{
+          "email" => "test@example.com",
+          "password" => "password123"
+        })
+
+      # Sign in with email
+      {:ok, signed_in_user} =
+        AshAuthentication.Strategy.action(strategy, :sign_in, %{
+          "email" => "test@example.com",
+          "password" => "password123"
+        })
+
+      assert signed_in_user.id == user.id
+      assert to_string(signed_in_user.email) == "test@example.com"
+    end
+
+    test "sign in fails with wrong password" do
+      # Get the password strategy
+      strategy = AshAuthentication.Info.strategy!(Mv.Accounts.User, :password)
+
+      # Create a user with password
+      {:ok, _user} =
+        AshAuthentication.Strategy.action(strategy, :register, %{
+          "email" => "test2@example.com",
+          "password" => "password123"
+        })
+
+      # Try to sign in with wrong password
+      {:error, _} =
+        AshAuthentication.Strategy.action(strategy, :sign_in, %{
+          "email" => "test2@example.com",
+          "password" => "wrongpassword"
+        })
+    end
+
+    test "sign in fails with non-existent email" do
+      # Get the password strategy
+      strategy = AshAuthentication.Info.strategy!(Mv.Accounts.User, :password)
+
+      # Try to sign in with non-existent email
+      {:error, _} =
+        AshAuthentication.Strategy.action(strategy, :sign_in, %{
+          "email" => "nonexistent@example.com",
+          "password" => "password123"
+        })
+    end
+
+    test "user gets member automatically created during registration" do
+      # Get the password strategy
+      strategy = AshAuthentication.Info.strategy!(Mv.Accounts.User, :password)
+
+      # Register a user
+      {:ok, user} =
+        AshAuthentication.Strategy.action(strategy, :register, %{
+          "email" => "member@example.com",
+          "password" => "password123"
+        })
+
+      # Reload user to get member_id
+      user = Ash.reload!(user, domain: Mv.Accounts)
+
+      # User should have a member
+      assert user.member_id
+
+      # Member should have the same email
+      member = Ash.get!(Mv.Membership.Member, user.member_id, domain: Mv.Membership)
+      assert member.member_email == "member@example.com"
+    end
+  end
+end
diff --git a/test/accounts/user_member_integration_test.exs b/test/accounts/user_member_integration_test.exs
new file mode 100644
index 0000000..4352448
--- /dev/null
+++ b/test/accounts/user_member_integration_test.exs
@@ -0,0 +1,71 @@
+defmodule Mv.Accounts.UserMemberIntegrationTest do
+  use Mv.DataCase, async: true
+  alias Mv.Accounts
+  alias Mv.Membership
+  alias Mv.Accounts.User.MemberCreationNotifier
+
+  describe "User-Member-Relation" do
+    test "ein User kann einem Member zugeordnet werden" do
+      {:ok, member} =
+        Membership.create_member(%{
+          member_email: "max@example.com"
+        })
+
+      {:ok, user} = Accounts.create_user(%{email: "user1@example.com", member_id: member.id})
+      assert user.member_id == member.id
+    end
+
+    test "ein Member kann nur einem User zugeordnet werden (unique constraint)" do
+      {:ok, member} =
+        Membership.create_member(%{
+          member_email: "anna@example.com"
+        })
+
+      {:ok, user1} = Accounts.create_user(%{email: "user2@example.com", member_id: member.id})
+      assert user1.member_id == member.id
+
+      {:error, %Ash.Error.Invalid{errors: errors}} =
+        Accounts.create_user(%{email: "user3@example.com", member_id: member.id})
+
+      assert Enum.any?(errors, fn error ->
+               error.message =~ "already been taken" or error.field == :member_id
+             end)
+    end
+
+    test "ein User ohne Member ist nicht erlaubt (bei Registrierung/Erstellung)" do
+      # Create user without member first
+      result = Accounts.create_user(%{email: "user4@example.com"})
+
+      case result do
+        {:ok, user} ->
+          # User is created but doesn't have member yet
+          assert user.member_id == nil
+
+          # Manually trigger the notifier to simulate automatic member creation
+          notification = %Ash.Notifier.Notification{
+            action: %{name: :create_user},
+            resource: Mv.Accounts.User,
+            data: user
+          }
+
+          {:ok, _updated_user} = MemberCreationNotifier.notify(notification)
+
+          # Reload user and verify member was created and assigned
+          user = Ash.reload!(user, domain: Mv.Accounts)
+          assert user.member_id, "User should have a member_id assigned after notifier"
+
+        {:error, _} ->
+          flunk("User creation should succeed")
+      end
+    end
+
+    test "ein Member kann ohne User existieren" do
+      {:ok, member} =
+        Membership.create_member(%{
+          member_email: "lisa@example.com"
+        })
+
+      assert member.id
+    end
+  end
+end
diff --git a/test/membership/member_email_test.exs b/test/membership/member_email_test.exs
new file mode 100644
index 0000000..3a37eff
--- /dev/null
+++ b/test/membership/member_email_test.exs
@@ -0,0 +1,99 @@
+defmodule Mv.Membership.MemberEmailTest do
+  use Mv.DataCase, async: true
+  alias Mv.Membership
+
+  describe "member_email and computed email field" do
+    test "email shows member_email when no user is assigned" do
+      {:ok, member} =
+        Membership.create_member(%{
+          member_email: "memberonly@example.com"
+        })
+
+      # Load the email calculation
+      member = Ash.load!(member, :email, domain: Membership)
+
+      assert member.member_email == "memberonly@example.com"
+      assert member.email == "memberonly@example.com"
+    end
+
+    test "updating member_email updates the computed email when no user is assigned" do
+      {:ok, member} =
+        Membership.create_member(%{
+          member_email: "old@example.com"
+        })
+
+      {:ok, member} =
+        Membership.update_member(member, %{member_email: "new@example.com"})
+
+      # Load the email calculation
+      member = Ash.load!(member, :email, domain: Membership)
+
+      assert member.member_email == "new@example.com"
+      assert member.email == "new@example.com"
+    end
+
+    test "member can be created without member_email" do
+      {:ok, member} =
+        Membership.create_member(%{})
+
+      # Load the email calculation with user relationship
+      member = Ash.load!(member, [:email, user: [:email]], domain: Membership)
+
+      assert member.member_email == nil
+      assert member.email == nil
+    end
+
+    test "email shows user.email when user is assigned" do
+      # Create a member first
+      {:ok, member} =
+        Membership.create_member(%{
+          member_email: "member@example.com"
+        })
+
+      # Create a user and assign it to the member
+      {:ok, _user} =
+        Mv.Accounts.create_user(%{
+          email: "user@example.com",
+          member_id: member.id
+        })
+
+      # Load the email calculation with user relationship
+      member = Ash.load!(member, [:email, user: [:email]], domain: Membership)
+
+      assert member.member_email == "member@example.com"
+      # Should show user email
+      assert member.email == "user@example.com"
+    end
+
+    test "email updates when user email changes" do
+      # Create a member
+      {:ok, member} =
+        Membership.create_member(%{
+          member_email: "member@example.com"
+        })
+
+      # Create a user
+      {:ok, user} =
+        Mv.Accounts.create_user(%{
+          email: "old@example.com",
+          member_id: member.id
+        })
+
+      # Load the email calculation initially
+      member = Ash.load!(member, [:email, user: [:email]], domain: Membership)
+      assert member.email == "old@example.com"
+
+      # Update user email
+      {:ok, _updated_user} =
+        Mv.Accounts.update_user(user, %{
+          email: "new@example.com"
+        })
+
+      # Reload member and check email calculation
+      member = Ash.reload!(member, domain: Membership)
+      member = Ash.load!(member, [:email, user: [:email]], domain: Membership)
+
+      assert member.email == "new@example.com"
+    end
+  end
+end
diff --git a/test/membership/member_test.exs b/test/membership/member_test.exs
index 7015d34..37e4a9d 100644
--- a/test/membership/member_test.exs
+++ b/test/membership/member_test.exs
@@ -8,7 +8,7 @@ defmodule Mv.Membership.MemberTest do
       last_name: "Doe",
       birth_date: ~D[1990-01-01],
       paid: true,
-      email: "john@example.com",
+      member_email: "john@example.com",
       phone_number: "+49123456789",
       join_date: ~D[2020-01-01],
       exit_date: nil,
@@ -19,28 +19,25 @@ defmodule Mv.Membership.MemberTest do
       postal_code: "12345"
     }
 
-    test "First name is required and must not be empty" do
-      attrs = Map.put(@valid_attrs, :first_name, "")
-      assert {:error, %Ash.Error.Invalid{errors: errors}} = Membership.create_member(attrs)
-      assert error_message(errors, :first_name) =~ "must be present"
+    test "First name is optional" do
+      attrs = Map.delete(@valid_attrs, :first_name)
+      assert {:ok, _member} = Membership.create_member(attrs)
     end
 
-    test "Last name is required and must not be empty" do
-      attrs = Map.put(@valid_attrs, :last_name, "")
-      assert {:error, %Ash.Error.Invalid{errors: errors}} = Membership.create_member(attrs)
-      assert error_message(errors, :last_name) =~ "must be present"
+    test "Last name is optional" do
+      attrs = Map.delete(@valid_attrs, :last_name)
+      assert {:ok, _member} = Membership.create_member(attrs)
     end
 
-    test "Email is required" do
-      attrs = Map.put(@valid_attrs, :email, "")
-      assert {:error, %Ash.Error.Invalid{errors: errors}} = Membership.create_member(attrs)
-      assert error_message(errors, :email) =~ "must be present"
+    test "Email is optional" do
+      attrs = Map.delete(@valid_attrs, :member_email)
+      assert {:ok, _member} = Membership.create_member(attrs)
     end
 
-    test "Email must be valid" do
-      attrs = Map.put(@valid_attrs, :email, "test@")
+    test "Email must be valid if provided" do
+      attrs = Map.put(@valid_attrs, :member_email, "test@")
       assert {:error, %Ash.Error.Invalid{errors: errors}} = Membership.create_member(attrs)
-      assert error_message(errors, :email) =~ "is not a valid email"
+      assert error_message(errors, :member_email) =~ "is not a valid email"
     end
 
     test "Birth date is optional but must not be in the future" do