diff --git a/lib/membership/phone_number.ex b/lib/membership/phone_number.ex
new file mode 100644
index 0000000..4613c43
--- /dev/null
+++ b/lib/membership/phone_number.ex
@@ -0,0 +1,28 @@
+defmodule Mv.Membership.PhoneNumber do
+  @match_pattern ~S/^\+?\d{5,16}$/
+  @match_regex Regex.compile!(@match_pattern)
+
+  use Ash.Type.NewType,
+    subtype_of: :string,
+    constraints: [
+      match: @match_pattern,
+      trim?: true
+    ]
+
+  @impl true
+  def cast_input("", _), do: {:ok, nil}
+
+  @impl true
+  def cast_input(value, _) when is_binary(value) do
+    value = String.trim(value)
+
+    if Regex.match?(@match_regex, value) do
+      {:ok, value}
+    else
+      :error
+    end
+  end
+
+  @impl true
+  def cast_input(_, _), do: :error
+end
diff --git a/lib/membership/property.ex b/lib/membership/property.ex
index 0bd5eab..6728da2 100644
--- a/lib/membership/property.ex
+++ b/lib/membership/property.ex
@@ -24,7 +24,8 @@ defmodule Mv.Membership.Property do
           date: [type: :date],
           integer: [type: :integer],
           string: [type: :string],
-          email: [type: Mv.Membership.Email]
+          email: [type: Mv.Membership.Email],
+          phone: [type: Mv.Membership.PhoneNumber]
         ]
       ]
   end
diff --git a/lib/membership/property_type.ex b/lib/membership/property_type.ex
index 8e42fa6..18215b4 100644
--- a/lib/membership/property_type.ex
+++ b/lib/membership/property_type.ex
@@ -19,7 +19,7 @@ defmodule Mv.Membership.PropertyType do
     attribute :name, :string, allow_nil?: false, public?: true
 
     attribute :value_type, :atom,
-      constraints: [one_of: [:string, :integer, :boolean, :date, :email]],
+      constraints: [one_of: [:string, :integer, :boolean, :date, :email, :phone]],
       allow_nil?: false,
       description: "Definies the datatype `Property.value` is interpreted as"