diff --git a/lib/mv/membership/import/header_mapper.ex b/lib/mv/membership/import/header_mapper.ex
index 709e156..d96d96e 100644
--- a/lib/mv/membership/import/header_mapper.ex
+++ b/lib/mv/membership/import/header_mapper.ex
@@ -17,15 +17,24 @@ defmodule Mv.Membership.Import.HeaderMapper do
 
   ## Member Field Mapping
 
-  Maps CSV headers to canonical member fields:
-  - `email` (required)
-  - `first_name` (optional)
-  - `last_name` (optional)
-  - `street` (optional)
-  - `postal_code` (optional)
-  - `city` (optional)
+  Maps CSV headers to canonical member fields (same as `Mv.Constants.member_fields()` for
+  importable attributes). All DB-backed member attributes can be imported.
 
-  Supports both English and German variants (e.g., "Email" / "E-Mail", "First Name" / "Vorname").
+  - `email` (required)
+  - `first_name`, `last_name` (optional)
+  - `join_date`, `exit_date` (optional, ISO-8601 date)
+  - `notes` (optional)
+  - `country`, `city`, `street`, `house_number`, `postal_code` (optional)
+  - `membership_fee_start_date` (optional, ISO-8601 date)
+
+  Supports English and German header variants (e.g. "Email" / "E-Mail", "Join Date" / "Beitrittsdatum").
+
+  ## Fields not supported for import
+
+  - **membership_fee_status** – Computed (calculation from membership fee cycles). Not stored;
+    cannot be set via CSV. Export can include it.
+  - **groups** – Many-to-many relationship (through member_groups). Import would require
+    resolving group names/slugs to IDs and creating associations; not in current import scope.
 
   ## Custom Field Detection
 
@@ -75,11 +84,37 @@ defmodule Mv.Membership.Import.HeaderMapper do
       "nachname",
       "familienname"
     ],
+    join_date: [
+      "join date",
+      "join_date",
+      "beitrittsdatum",
+      "beitritts-datum"
+    ],
+    exit_date: [
+      "exit date",
+      "exit_date",
+      "austrittsdatum",
+      "austritts-datum"
+    ],
+    notes: [
+      "notes",
+      "notizen",
+      "bemerkungen"
+    ],
     street: [
       "street",
       "address",
       "strasse"
     ],
+    house_number: [
+      "house number",
+      "house_number",
+      "house no",
+      "hausnummer",
+      "nr",
+      "nr.",
+      "nummer"
+    ],
     postal_code: [
       "postal code",
       "postal_code",
@@ -93,6 +128,18 @@ defmodule Mv.Membership.Import.HeaderMapper do
       "town",
       "stadt",
       "ort"
+    ],
+    country: [
+      "country",
+      "land",
+      "staat"
+    ],
+    membership_fee_start_date: [
+      "membership fee start date",
+      "membership_fee_start_date",
+      "fee start",
+      "beitragsbeginn",
+      "beitrags-beginn"
     ]
   }
 
diff --git a/lib/mv/membership/import/member_csv.ex b/lib/mv/membership/import/member_csv.ex
index c967bf5..23e0d93 100644
--- a/lib/mv/membership/import/member_csv.ex
+++ b/lib/mv/membership/import/member_csv.ex
@@ -549,9 +549,12 @@ defmodule Mv.Membership.Import.MemberCSV do
          line_number,
          actor
        ) do
+    # Convert empty strings to nil for date fields so Ash accepts them
+    member_attrs = sanitize_date_fields(trimmed_member_attrs)
+
     # Create member with custom field values
     member_attrs_with_cf =
-      trimmed_member_attrs
+      member_attrs
       |> Map.put(:custom_field_values, custom_field_values)
 
     # Only include custom_field_values if not empty
@@ -793,6 +796,23 @@ defmodule Mv.Membership.Import.MemberCSV do
     end)
   end
 
+  # Converts empty strings to nil for date fields so Ash can accept them
+  @date_fields [:join_date, :exit_date, :membership_fee_start_date]
+
+  defp sanitize_date_fields(attrs) when is_map(attrs) do
+    Enum.reduce(@date_fields, attrs, fn field, acc ->
+      put_date_field(acc, field, Map.get(acc, field))
+    end)
+  end
+
+  defp put_date_field(acc, field, ""), do: Map.put(acc, field, nil)
+
+  defp put_date_field(acc, field, val) when is_binary(val) do
+    if String.trim(val) == "", do: Map.put(acc, field, nil), else: acc
+  end
+
+  defp put_date_field(acc, _field, _), do: acc
+
   # Formats Ash errors into MemberCSV.Error structs
   defp format_ash_error(%Ash.Error.Invalid{errors: errors}, line_number, email) do
     # Try to find email-related errors first (for better error messages)