diff --git a/Justfile b/Justfile
index f44be78..4480991 100644
--- a/Justfile
+++ b/Justfile
@@ -9,6 +9,7 @@ migrate-database:
 
 reset-database:
     mix ash.reset
+    MIX_ENV=test mix ash.setup
 
 seed-database:
     mix run priv/repo/seeds.exs
diff --git a/lib/membership/member.ex b/lib/membership/member.ex
index 0538f45..55e6a0e 100644
--- a/lib/membership/member.ex
+++ b/lib/membership/member.ex
@@ -14,6 +14,23 @@ defmodule Mv.Membership.Member do
     create :create_member do
       primary? true
       argument :properties, {:array, :map}
+
+      accept [
+        :first_name,
+        :last_name,
+        :email,
+        :birth_date,
+        :paid,
+        :phone_number,
+        :join_date,
+        :exit_date,
+        :notes,
+        :city,
+        :street,
+        :house_number,
+        :postal_code
+      ]
+
       change manage_relationship(:properties, type: :create)
     end
 
@@ -21,12 +38,176 @@ defmodule Mv.Membership.Member do
       primary? true
       require_atomic? false
       argument :properties, {:array, :map}
+
+      accept [
+        :first_name,
+        :last_name,
+        :email,
+        :birth_date,
+        :paid,
+        :phone_number,
+        :join_date,
+        :exit_date,
+        :notes,
+        :city,
+        :street,
+        :house_number,
+        :postal_code
+      ]
+
       change manage_relationship(:properties, on_match: :update, on_no_match: :create)
     end
   end
 
   attributes do
     uuid_v7_primary_key :id
+
+    attribute :first_name, :string do
+      allow_nil? false
+      constraints min_length: 1
+    end
+
+    attribute :last_name, :string do
+      allow_nil? false
+      constraints min_length: 1
+    end
+
+    attribute :email, :string do
+      allow_nil? false
+      constraints min_length: 5, max_length: 254
+    end
+
+    attribute :birth_date, :date do
+      allow_nil? true
+    end
+
+    attribute :paid, :boolean do
+      allow_nil? true
+    end
+
+    attribute :phone_number, :string do
+      allow_nil? true
+    end
+
+    attribute :join_date, :date do
+      allow_nil? true
+    end
+
+    attribute :exit_date, :date do
+      allow_nil? true
+    end
+
+    attribute :notes, :string do
+      allow_nil? true
+    end
+
+    attribute :city, :string do
+      allow_nil? true
+    end
+
+    attribute :street, :string do
+      allow_nil? true
+    end
+
+    attribute :house_number, :string do
+      allow_nil? true
+    end
+
+    attribute :postal_code, :string do
+      allow_nil? true
+    end
+  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)
+
+    # Birth date not in the future
+    validate fn changeset, _ ->
+      birth_date = Ash.Changeset.get_attribute(changeset, :birth_date)
+
+      if birth_date && Date.compare(birth_date, Date.utc_today()) == :gt do
+        {:error, field: :birth_date, message: "cannot be in the future"}
+      else
+        :ok
+      end
+    end
+
+    # Join date not in the future
+    validate fn changeset, _ ->
+      join_date = Ash.Changeset.get_attribute(changeset, :join_date)
+
+      if join_date && Date.compare(join_date, Date.utc_today()) == :gt do
+        {:error, field: :join_date, message: "cannot be in the future"}
+      else
+        :ok
+      end
+    end
+
+    # Exit date not before join date
+    validate fn changeset, _ ->
+      join_date = Ash.Changeset.get_attribute(changeset, :join_date)
+      exit_date = Ash.Changeset.get_attribute(changeset, :exit_date)
+
+      if join_date && exit_date && Date.compare(exit_date, join_date) == :lt do
+        {:error, field: :exit_date, message: "cannot be before join date"}
+      else
+        :ok
+      end
+    end
+
+    # Phone number format (only if set)
+    validate fn changeset, _ ->
+      phone = Ash.Changeset.get_attribute(changeset, :phone_number)
+
+      if phone && !Regex.match?(~r/^\+?[0-9\- ]{6,20}$/, phone) do
+        {:error, field: :phone_number, message: "is not a valid phone number"}
+      else
+        :ok
+      end
+    end
+
+    # Postal code format (only if set)
+    validate fn changeset, _ ->
+      postal_code = Ash.Changeset.get_attribute(changeset, :postal_code)
+
+      if postal_code && !Regex.match?(~r/^\d{5}$/, postal_code) do
+        {:error, field: :postal_code, message: "must consist of 5 digits"}
+      else
+        :ok
+      end
+    end
+
+    # paid must be boolean if set
+    validate fn changeset, _ ->
+      paid = Ash.Changeset.get_attribute(changeset, :paid)
+
+      if not is_nil(paid) and not is_boolean(paid) do
+        {:error, field: :paid, message: "must be true or false"}
+      else
+        :ok
+      end
+    end
+
+    # Email validation with EctoCommons.EmailValidator
+    validate fn changeset, _ ->
+      email = Ash.Changeset.get_attribute(changeset, :email)
+
+      changeset2 =
+        {%{}, %{email: :string}}
+        |> Ecto.Changeset.cast(%{email: 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
   end
 
   relationships do
diff --git a/lib/membership/property_type.ex b/lib/membership/property_type.ex
index 8e42fa6..7444c13 100644
--- a/lib/membership/property_type.ex
+++ b/lib/membership/property_type.ex
@@ -21,7 +21,7 @@ defmodule Mv.Membership.PropertyType do
     attribute :value_type, :atom,
       constraints: [one_of: [:string, :integer, :boolean, :date, :email]],
       allow_nil?: false,
-      description: "Definies the datatype `Property.value` is interpreted as"
+      description: "Defines the datatype `Property.value` is interpreted as"
 
     attribute :description, :string, allow_nil?: true, public?: true
 
diff --git a/mix.exs b/mix.exs
index fd60217..a1e30ab 100644
--- a/mix.exs
+++ b/mix.exs
@@ -69,7 +69,8 @@ defmodule Mv.MixProject do
       {:bandit, "~> 1.5"},
       {:mix_audit, "~> 2.1", only: [:dev, :test], runtime: false},
       {:sobelow, "~> 0.14", only: [:dev, :test], runtime: false},
-      {:credo, "~> 1.7", only: [:dev, :test], runtime: false}
+      {:credo, "~> 1.7", only: [:dev, :test], runtime: false},
+      {:ecto_commons, "~> 0.3"}
     ]
   end
 
diff --git a/mix.lock b/mix.lock
index 8e179eb..962f445 100644
--- a/mix.lock
+++ b/mix.lock
@@ -13,9 +13,11 @@
   "decimal": {:hex, :decimal, "2.3.0", "3ad6255aa77b4a3c4f818171b12d237500e63525c2fd056699967a3e7ea20f62", [:mix], [], "hexpm", "a4d66355cb29cb47c3cf30e71329e58361cfcb37c34235ef3bf1d7bf3773aeac"},
   "dns_cluster": {:hex, :dns_cluster, "0.2.0", "aa8eb46e3bd0326bd67b84790c561733b25c5ba2fe3c7e36f28e88f384ebcb33", [:mix], [], "hexpm", "ba6f1893411c69c01b9e8e8f772062535a4cf70f3f35bcc964a324078d8c8240"},
   "ecto": {:hex, :ecto, "3.12.6", "8bf762dc5b87d85b7aca7ad5fe31ef8142a84cea473a3381eb933bd925751300", [:mix], [{:decimal, "~> 2.0", [hex: :decimal, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}, {:telemetry, "~> 0.4 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "4c0cba01795463eebbcd9e4b5ef53c1ee8e68b9c482baef2a80de5a61e7a57fe"},
+  "ecto_commons": {:hex, :ecto_commons, "0.3.6", "7b1d9e59396cf8c8cbe5a26d50d03f9b6d0fe6c640210dd503622f276f1e59bb", [:mix], [{:burnex, "~> 3.0", [hex: :burnex, repo: "hexpm", optional: true]}, {:ecto, "~> 3.4", [hex: :ecto, repo: "hexpm", optional: false]}, {:ex_phone_number, "~> 0.2", [hex: :ex_phone_number, repo: "hexpm", optional: false]}, {:luhn, "~> 0.3.0", [hex: :luhn, repo: "hexpm", optional: false]}], "hexpm", "3f12981a1e398f206c5d2014e7b732b7ec91b110b9cb84875cb5b28fc75d7a0a"},
   "ecto_sql": {:hex, :ecto_sql, "3.12.1", "c0d0d60e85d9ff4631f12bafa454bc392ce8b9ec83531a412c12a0d415a3a4d0", [:mix], [{:db_connection, "~> 2.4.1 or ~> 2.5", [hex: :db_connection, repo: "hexpm", optional: false]}, {:ecto, "~> 3.12", [hex: :ecto, repo: "hexpm", optional: false]}, {:myxql, "~> 0.7", [hex: :myxql, repo: "hexpm", optional: true]}, {:postgrex, "~> 0.19 or ~> 1.0", [hex: :postgrex, repo: "hexpm", optional: true]}, {:tds, "~> 2.1.1 or ~> 2.2", [hex: :tds, repo: "hexpm", optional: true]}, {:telemetry, "~> 0.4.0 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "aff5b958a899762c5f09028c847569f7dfb9cc9d63bdb8133bff8a5546de6bf5"},
   "esbuild": {:hex, :esbuild, "0.10.0", "b0aa3388a1c23e727c5a3e7427c932d89ee791746b0081bbe56103e9ef3d291f", [:mix], [{:jason, "~> 1.4", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "468489cda427b974a7cc9f03ace55368a83e1a7be12fba7e30969af78e5f8c70"},
   "ets": {:hex, :ets, "0.9.0", "79c6a6c205436780486f72d84230c6cba2f8a9920456750ddd1e47389107d5fd", [:mix], [], "hexpm", "2861fdfb04bcaeff370f1a5904eec864f0a56dcfebe5921ea9aadf2a481c822b"},
+  "ex_phone_number": {:hex, :ex_phone_number, "0.4.5", "2065cc48c3e9d1ed9821f50877c32f2f6898362cb990f44147ca217c5d1374ed", [:mix], [{:sweet_xml, "~> 0.7", [hex: :sweet_xml, repo: "hexpm", optional: false]}], "hexpm", "67163f8706f8cbfef1b1f4b9230c461f19786d0d79fd0b22cbeeefc6f0b99d4a"},
   "expo": {:hex, :expo, "1.1.0", "f7b9ed7fb5745ebe1eeedf3d6f29226c5dd52897ac67c0f8af62a07e661e5c75", [:mix], [], "hexpm", "fbadf93f4700fb44c331362177bdca9eeb8097e8b0ef525c9cc501cb9917c960"},
   "file_system": {:hex, :file_system, "1.1.0", "08d232062284546c6c34426997dd7ef6ec9f8bbd090eb91780283c9016840e8f", [:mix], [], "hexpm", "bfcf81244f416871f2a2e15c1b515287faa5db9c6bcf290222206d120b3d43f6"},
   "finch": {:hex, :finch, "0.19.0", "c644641491ea854fc5c1bbaef36bfc764e3f08e7185e1f084e35e0672241b76d", [:mix], [{:mime, "~> 1.0 or ~> 2.0", [hex: :mime, repo: "hexpm", optional: false]}, {:mint, "~> 1.6.2 or ~> 1.7", [hex: :mint, repo: "hexpm", optional: false]}, {:nimble_options, "~> 0.4 or ~> 1.0", [hex: :nimble_options, repo: "hexpm", optional: false]}, {:nimble_pool, "~> 1.1", [hex: :nimble_pool, repo: "hexpm", optional: false]}, {:telemetry, "~> 0.4 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "fc5324ce209125d1e2fa0fcd2634601c52a787aff1cd33ee833664a5af4ea2b6"},
@@ -30,6 +32,7 @@
   "jason": {:hex, :jason, "1.4.4", "b9226785a9aa77b6857ca22832cffa5d5011a667207eb2a0ad56adb5db443b8a", [:mix], [{:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "c5eb0cab91f094599f94d55bc63409236a8ec69a21a67814529e8d5f6cc90b3b"},
   "libgraph": {:hex, :libgraph, "0.16.0", "3936f3eca6ef826e08880230f806bfea13193e49bf153f93edcf0239d4fd1d07", [:mix], [], "hexpm", "41ca92240e8a4138c30a7e06466acc709b0cbb795c643e9e17174a178982d6bf"},
   "live_debugger": {:hex, :live_debugger, "0.2.4", "2e0b02874ca562ba2d8cebb9e024c25c0ae9c1f4ee499135a70814e1dea6183e", [:mix], [{:igniter, ">= 0.5.40 and < 1.0.0-0", [hex: :igniter, repo: "hexpm", optional: true]}, {:phoenix_live_view, "~> 0.20.4 or ~> 1.0", [hex: :phoenix_live_view, repo: "hexpm", optional: false]}], "hexpm", "bfd0db143be54ccf2872f15bfd2209fbec1083d0b06b81b4cedeecb2fa9ac208"},
+  "luhn": {:hex, :luhn, "0.3.3", "5aa0c6a32c2db4b9db9f9b883ba8301c1ae169d57199b9e6cb1ba2707bc51d96", [:mix], [], "hexpm", "3e823a913a25aab51352c727f135278d22954874d5f0835be81ed4fec3daf78d"},
   "mime": {:hex, :mime, "2.0.7", "b8d739037be7cd402aee1ba0306edfdef982687ee7e9859bee6198c1e7e2f128", [:mix], [], "hexpm", "6171188e399ee16023ffc5b76ce445eb6d9672e2e241d2df6050f3c771e80ccd"},
   "mint": {:hex, :mint, "1.7.1", "113fdb2b2f3b59e47c7955971854641c61f378549d73e829e1768de90fc1abf1", [:mix], [{:castore, "~> 0.1.0 or ~> 1.0", [hex: :castore, repo: "hexpm", optional: true]}, {:hpax, "~> 0.1.1 or ~> 0.2.0 or ~> 1.0", [hex: :hpax, repo: "hexpm", optional: false]}], "hexpm", "fceba0a4d0f24301ddee3024ae116df1c3f4bb7a563a731f45fdfeb9d39a231b"},
   "mix_audit": {:hex, :mix_audit, "2.1.5", "c0f77cee6b4ef9d97e37772359a187a166c7a1e0e08b50edf5bf6959dfe5a016", [:make, :mix], [{:jason, "~> 1.4", [hex: :jason, repo: "hexpm", optional: false]}, {:yaml_elixir, "~> 2.11", [hex: :yaml_elixir, repo: "hexpm", optional: false]}], "hexpm", "87f9298e21da32f697af535475860dc1d3617a010e0b418d2ec6142bc8b42d69"},
@@ -58,6 +61,7 @@
   "splode": {:hex, :splode, "0.2.9", "3a2776e187c82f42f5226b33b1220ccbff74f4bcc523dd4039c804caaa3ffdc7", [:mix], [], "hexpm", "8002b00c6e24f8bd1bcced3fbaa5c33346048047bb7e13d2f3ad428babbd95c3"},
   "stream_data": {:hex, :stream_data, "1.2.0", "58dd3f9e88afe27dc38bef26fce0c84a9e7a96772b2925c7b32cd2435697a52b", [:mix], [], "hexpm", "eb5c546ee3466920314643edf68943a5b14b32d1da9fe01698dc92b73f89a9ed"},
   "swoosh": {:hex, :swoosh, "1.19.2", "b2325aa7cd2bcd63ba023fa07a73dfc4f80660a592d40912975a879966ed9b7b", [:mix], [{:bandit, ">= 1.0.0", [hex: :bandit, repo: "hexpm", optional: true]}, {:cowboy, "~> 1.1 or ~> 2.4", [hex: :cowboy, repo: "hexpm", optional: true]}, {:ex_aws, "~> 2.1", [hex: :ex_aws, repo: "hexpm", optional: true]}, {:finch, "~> 0.6", [hex: :finch, repo: "hexpm", optional: true]}, {:gen_smtp, "~> 0.13 or ~> 1.0", [hex: :gen_smtp, repo: "hexpm", optional: true]}, {:hackney, "~> 1.9", [hex: :hackney, repo: "hexpm", optional: true]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}, {:mail, "~> 0.2", [hex: :mail, repo: "hexpm", optional: true]}, {:mime, "~> 1.1 or ~> 2.0", [hex: :mime, repo: "hexpm", optional: false]}, {:mua, "~> 0.2.3", [hex: :mua, repo: "hexpm", optional: true]}, {:multipart, "~> 0.4", [hex: :multipart, repo: "hexpm", optional: true]}, {:plug, "~> 1.9", [hex: :plug, repo: "hexpm", optional: true]}, {:plug_cowboy, ">= 1.0.0", [hex: :plug_cowboy, repo: "hexpm", optional: true]}, {:req, "~> 0.5.10 or ~> 0.6 or ~> 1.0", [hex: :req, repo: "hexpm", optional: true]}, {:telemetry, "~> 0.4.2 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "cab7ef7c2c94c68fe21d3da26f6b86db118fdf4e7024ccb5842a4972c1056837"},
+  "sweet_xml": {:hex, :sweet_xml, "0.7.5", "803a563113981aaac202a1dbd39771562d0ad31004ddbfc9b5090bdcd5605277", [:mix], [], "hexpm", "193b28a9b12891cae351d81a0cead165ffe67df1b73fe5866d10629f4faefb12"},
   "tailwind": {:hex, :tailwind, "0.3.1", "a89d2835c580748c7a975ad7dd3f2ea5e63216dc16d44f9df492fbd12c094bed", [:mix], [], "hexpm", "98a45febdf4a87bc26682e1171acdedd6317d0919953c353fcd1b4f9f4b676a2"},
   "telemetry": {:hex, :telemetry, "1.3.0", "fedebbae410d715cf8e7062c96a1ef32ec22e764197f70cda73d82778d61e7a2", [:rebar3], [], "hexpm", "7015fc8919dbe63764f4b4b87a95b7c0996bd539e0d499be6ec9d7f3875b79e6"},
   "telemetry_metrics": {:hex, :telemetry_metrics, "1.1.0", "5bd5f3b5637e0abea0426b947e3ce5dd304f8b3bc6617039e2b5a008adc02f8f", [:mix], [{:telemetry, "~> 0.4 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "e7b79e8ddfde70adb6db8a6623d1778ec66401f366e9a8f5dd0955c56bc8ce67"},
diff --git a/priv/repo/migrations/20250617090641_member_fields.exs b/priv/repo/migrations/20250617090641_member_fields.exs
new file mode 100644
index 0000000..36a80eb
--- /dev/null
+++ b/priv/repo/migrations/20250617090641_member_fields.exs
@@ -0,0 +1,45 @@
+defmodule Mv.Repo.Migrations.MemberFields 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
+      add :first_name, :text, null: false
+      add :last_name, :text, null: false
+      add :email, :text, null: false
+      add :birth_date, :date
+      add :paid, :boolean
+      add :phone_number, :text
+      add :join_date, :date
+      add :exit_date, :date
+      add :notes, :text
+      add :city, :text
+      add :street, :text
+      add :house_number, :text
+      add :postal_code, :text
+    end
+  end
+
+  def down do
+    alter table(:members) do
+      remove :postal_code
+      remove :house_number
+      remove :street
+      remove :city
+      remove :notes
+      remove :exit_date
+      remove :join_date
+      remove :phone_number
+      remove :paid
+      remove :birth_date
+      remove :email
+      remove :last_name
+      remove :first_name
+    end
+  end
+end
diff --git a/priv/repo/seeds.exs b/priv/repo/seeds.exs
index 39327d0..2bdcb18 100644
--- a/priv/repo/seeds.exs
+++ b/priv/repo/seeds.exs
@@ -7,37 +7,37 @@ alias Mv.Membership
 
 for attrs <- [
       %{
-        name: "Vorname",
+        name: "First Name",
         value_type: :string,
-        description: "Vorname des Mitglieds",
+        description: "Member's first name",
         immutable: true,
         required: true
       },
       %{
-        name: "Nachname",
+        name: "Last Name",
         value_type: :string,
-        description: "Nachname des Mitglieds",
+        description: "Member's last name",
         immutable: true,
         required: true
       },
       %{
-        name: "Geburtsdatum",
+        name: "Birth Date",
         value_type: :date,
-        description: "Geburtsdatum des Mitglieds",
+        description: "Member's birth date",
         immutable: true,
         required: true
       },
       %{
-        name: "Bezahlt",
+        name: "Paid",
         value_type: :boolean,
-        description: "Status des Mitgliedsbeitrages des Mitglieds",
+        description: "Member's payment status",
         immutable: true,
         required: true
       },
       %{
         name: "Email",
         value_type: :email,
-        description: "Email-Adresse des Mitglieds",
+        description: "Member's email address",
         immutable: true,
         required: true
       }
diff --git a/priv/resource_snapshots/repo/members/20250617090641.json b/priv/resource_snapshots/repo/members/20250617090641.json
new file mode 100644
index 0000000..9e2d991
--- /dev/null
+++ b/priv/resource_snapshots/repo/members/20250617090641.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?": false,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "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": "CF80317E7EE409618E08458B10EE122FF605640DDA8CD6000B433F1979614F5D",
+  "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/membership/member_test.exs b/test/membership/member_test.exs
new file mode 100644
index 0000000..7015d34
--- /dev/null
+++ b/test/membership/member_test.exs
@@ -0,0 +1,110 @@
+defmodule Mv.Membership.MemberTest do
+  use Mv.DataCase, async: false
+  alias Mv.Membership
+
+  describe "Fields and Validations" do
+    @valid_attrs %{
+      first_name: "John",
+      last_name: "Doe",
+      birth_date: ~D[1990-01-01],
+      paid: true,
+      email: "john@example.com",
+      phone_number: "+49123456789",
+      join_date: ~D[2020-01-01],
+      exit_date: nil,
+      notes: "Test note",
+      city: "Berlin",
+      street: "Main Street",
+      house_number: "1A",
+      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"
+    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"
+    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"
+    end
+
+    test "Email must be valid" do
+      attrs = Map.put(@valid_attrs, :email, "test@")
+      assert {:error, %Ash.Error.Invalid{errors: errors}} = Membership.create_member(attrs)
+      assert error_message(errors, :email) =~ "is not a valid email"
+    end
+
+    test "Birth date is optional but must not be in the future" do
+      attrs = Map.put(@valid_attrs, :birth_date, Date.utc_today() |> Date.add(1))
+      assert {:error, %Ash.Error.Invalid{errors: errors}} = Membership.create_member(attrs)
+      assert error_message(errors, :birth_date) =~ "cannot be in the future"
+    end
+
+    test "Paid is optional but must be boolean if specified" do
+      attrs = Map.put(@valid_attrs, :paid, nil)
+      attrs2 = Map.put(@valid_attrs, :paid, "yes")
+      assert {:ok, _member} = Membership.create_member(Map.delete(attrs, :paid))
+      assert {:error, %Ash.Error.Invalid{errors: errors}} = Membership.create_member(attrs2)
+      assert error_message(errors, :paid) =~ "is invalid"
+    end
+
+    test "Phone number is optional but must have a valid format if specified" do
+      attrs = Map.put(@valid_attrs, :phone_number, "abc")
+      assert {:error, %Ash.Error.Invalid{errors: errors}} = Membership.create_member(attrs)
+      assert error_message(errors, :phone_number) =~ "is not a valid phone number"
+      attrs2 = Map.delete(@valid_attrs, :phone_number)
+      assert {:ok, _member} = Membership.create_member(attrs2)
+    end
+
+    test "Join date is optional but must not be in the future" do
+      attrs = Map.put(@valid_attrs, :join_date, Date.utc_today() |> Date.add(1))
+      assert {:error, %Ash.Error.Invalid{errors: errors}} = Membership.create_member(attrs)
+      assert error_message(errors, :join_date) =~ "cannot be in the future"
+      attrs2 = Map.delete(@valid_attrs, :join_date)
+      assert {:ok, _member} = Membership.create_member(attrs2)
+    end
+
+    test "Exit date is optional but must not be before join date if both are specified" do
+      attrs = Map.put(@valid_attrs, :exit_date, ~D[2010-01-01])
+      assert {:error, %Ash.Error.Invalid{errors: errors}} = Membership.create_member(attrs)
+      assert error_message(errors, :exit_date) =~ "cannot be before join date"
+      attrs2 = Map.delete(@valid_attrs, :exit_date)
+      assert {:ok, _member} = Membership.create_member(attrs2)
+    end
+
+    test "Notes is optional" do
+      attrs = Map.delete(@valid_attrs, :notes)
+      assert {:ok, _member} = Membership.create_member(attrs)
+    end
+
+    test "City, street, house number are optional" do
+      attrs = @valid_attrs |> Map.drop([:city, :street, :house_number])
+      assert {:ok, _member} = Membership.create_member(attrs)
+    end
+
+    test "Postal code is optional but must have 5 digits if specified" do
+      attrs = Map.put(@valid_attrs, :postal_code, "1234")
+      assert {:error, %Ash.Error.Invalid{errors: errors}} = Membership.create_member(attrs)
+      assert error_message(errors, :postal_code) =~ "must consist of 5 digits"
+      attrs2 = Map.delete(@valid_attrs, :postal_code)
+      assert {:ok, _member} = Membership.create_member(attrs2)
+    end
+  end
+
+  # Helper function for error evaluation
+  defp error_message(errors, field) do
+    errors
+    |> Enum.filter(fn err -> Map.get(err, :field) == field end)
+    |> Enum.map(&Map.get(&1, :message, ""))
+    |> List.first()
+  end
+end