diff --git a/lib/mv/membership/member_export.ex b/lib/mv/membership/member_export.ex
index 1c004f3..16341c4 100644
--- a/lib/mv/membership/member_export.ex
+++ b/lib/mv/membership/member_export.ex
@@ -388,20 +388,25 @@ defmodule Mv.Membership.MemberExport do
   - `opts` - Map with `:selected_ids`, `:cycle_status_filter`, `:show_current_cycle`, `:boolean_filters`.
   - `custom_fields_by_id` - Map of custom field id => custom field struct (for boolean filter resolution).
 
-  When `opts.selected_ids` is not empty, returns `members` unchanged. Otherwise applies
-  cycle status filter and boolean custom field filters.
+  When `opts.selected_ids` is not empty, returns `members` unchanged (selected_ids
+  override filters). Otherwise applies cycle status filter and boolean custom field filters.
+
+  Uses `Map.get(opts, :selected_ids, [])` so that `nil` or a missing key is treated as
+  "export all" and filters are applied.
   """
   @spec apply_export_filters([struct()], map(), map()) :: [struct()]
   def apply_export_filters(members, opts, custom_fields_by_id) do
-    if opts[:selected_ids] != [] do
-      members
-    else
+    selected_ids = Map.get(opts, :selected_ids, [])
+
+    if Enum.empty?(selected_ids) do
       members
       |> apply_cycle_status_filter(opts[:cycle_status_filter], opts[:show_current_cycle])
       |> Index.apply_boolean_custom_field_filters(
         Map.get(opts, :boolean_filters, %{}),
         Map.values(custom_fields_by_id)
       )
+    else
+      members
     end
   end
 
diff --git a/lib/mv_web/controllers/member_export_controller.ex b/lib/mv_web/controllers/member_export_controller.ex
index 2c299a3..9b08f5d 100644
--- a/lib/mv_web/controllers/member_export_controller.ex
+++ b/lib/mv_web/controllers/member_export_controller.ex
@@ -66,6 +66,9 @@ defmodule MvWeb.MemberExportController do
   defp parse_and_validate(params) do
     member_fields = filter_allowed_member_fields(extract_list(params, "member_fields"))
     {selectable_member_fields, computed_fields} = split_member_fields(member_fields)
+    custom_field_ids = filter_valid_uuids(extract_list(params, "custom_field_ids"))
+    boolean_filters = extract_boolean_filters(params)
+    custom_field_ids_union = (custom_field_ids ++ Map.keys(boolean_filters)) |> Enum.uniq()
 
     %{
       selected_ids: filter_valid_uuids(extract_list(params, "selected_ids")),
@@ -73,16 +76,19 @@ defmodule MvWeb.MemberExportController do
       selectable_member_fields: selectable_member_fields,
       computed_fields:
         computed_fields ++ filter_existing_atoms(extract_list(params, "computed_fields")),
-      custom_field_ids: filter_valid_uuids(extract_list(params, "custom_field_ids")),
+      custom_field_ids: custom_field_ids,
+      custom_field_ids_union: custom_field_ids_union,
       query: extract_string(params, "query"),
       sort_field: extract_string(params, "sort_field"),
       sort_order: extract_sort_order(params),
       show_current_cycle: extract_boolean(params, "show_current_cycle"),
       cycle_status_filter: extract_cycle_status_filter(params),
-      boolean_filters: extract_boolean_filters(params)
+      boolean_filters: boolean_filters
     }
   end
 
+  # Only paid and unpaid are supported for list/export filter. :suspended exists in the
+  # domain (e.g. membership fee status display) but is not used as a filter in the member index.
   defp extract_cycle_status_filter(params) do
     case Map.get(params, "cycle_status_filter") do
       "paid" -> :paid
@@ -91,13 +97,15 @@ defmodule MvWeb.MemberExportController do
     end
   end
 
+  # Normalizes values so that "true"/"false" from query/form encoding are accepted as well as JSON booleans.
   defp extract_boolean_filters(params) do
     case Map.get(params, "boolean_filters") do
       map when is_map(map) ->
         map
         |> Enum.filter(fn {k, v} ->
-          is_binary(k) and is_boolean(v) and match?({:ok, _}, Ecto.UUID.cast(k))
+          is_binary(k) and match?({:ok, _}, Ecto.UUID.cast(k)) and boolean_value?(v)
         end)
+        |> Enum.map(fn {k, v} -> {k, normalize_boolean_value(v)} end)
         |> Enum.into(%{})
 
       _ ->
@@ -105,6 +113,14 @@ defmodule MvWeb.MemberExportController do
     end
   end
 
+  defp boolean_value?(v) when is_boolean(v), do: true
+  defp boolean_value?(v) when v in ["true", "false"], do: true
+  defp boolean_value?(_), do: false
+
+  defp normalize_boolean_value(v) when is_boolean(v), do: v
+  defp normalize_boolean_value("true"), do: true
+  defp normalize_boolean_value("false"), do: false
+
   defp split_member_fields(member_fields) do
     domain_fields = Mv.Constants.member_fields() |> Enum.map(&Atom.to_string/1)
     selectable = Enum.filter(member_fields, fn f -> f in domain_fields end)
@@ -181,10 +197,8 @@ defmodule MvWeb.MemberExportController do
       parsed
       |> ensure_sort_custom_field_loaded()
 
-    custom_field_ids_union =
-      (parsed.custom_field_ids ++ Map.keys(parsed.boolean_filters || %{})) |> Enum.uniq()
-
-    with {:ok, custom_fields_by_id} <- load_custom_fields_by_id(custom_field_ids_union, actor),
+    with {:ok, custom_fields_by_id} <-
+           load_custom_fields_by_id(parsed.custom_field_ids_union, actor),
          {:ok, members} <- load_members_for_export(actor, parsed, custom_fields_by_id) do
       columns = build_columns(conn, parsed, custom_fields_by_id)
       csv_iodata = MembersCSV.export(members, columns)
@@ -202,13 +216,19 @@ defmodule MvWeb.MemberExportController do
     end
   end
 
-  defp ensure_sort_custom_field_loaded(%{custom_field_ids: ids, sort_field: sort_field} = parsed) do
+  defp ensure_sort_custom_field_loaded(
+         %{custom_field_ids: ids, custom_field_ids_union: union, sort_field: sort_field} = parsed
+       ) do
     case extract_sort_custom_field_id(sort_field) do
       nil ->
         parsed
 
       id ->
-        %{parsed | custom_field_ids: Enum.uniq([id | ids])}
+        %{
+          parsed
+          | custom_field_ids: Enum.uniq([id | ids]),
+            custom_field_ids_union: Enum.uniq([id | union])
+        }
     end
   end
 
@@ -260,9 +280,6 @@ defmodule MvWeb.MemberExportController do
   defp load_members_for_export(actor, parsed, custom_fields_by_id) do
     select_fields = [:id] ++ Enum.map(parsed.selectable_member_fields, &String.to_existing_atom/1)
 
-    custom_field_ids_union =
-      (parsed.custom_field_ids ++ Map.keys(parsed.boolean_filters || %{})) |> Enum.uniq()
-
     need_cycles =
       (parsed.computed_fields != [] and "membership_fee_status" in parsed.computed_fields) or
         parsed.cycle_status_filter != nil
@@ -277,7 +294,7 @@ defmodule MvWeb.MemberExportController do
       Member
       |> Ash.Query.new()
       |> Ash.Query.select(select_fields)
-      |> load_custom_field_values_query(custom_field_ids_union)
+      |> load_custom_field_values_query(parsed.custom_field_ids_union)
       |> maybe_load_cycles(need_cycles, parsed.show_current_cycle)
       |> maybe_load_groups(need_groups)
       |> maybe_load_membership_fee_type(need_membership_fee_type)
diff --git a/test/mv_web/controllers/member_export_controller_test.exs b/test/mv_web/controllers/member_export_controller_test.exs
index 9d9d197..a2dbfa2 100644
--- a/test/mv_web/controllers/member_export_controller_test.exs
+++ b/test/mv_web/controllers/member_export_controller_test.exs
@@ -119,6 +119,78 @@ defmodule MvWeb.MemberExportControllerTest do
       assert body =~ "Carol"
     end
 
+    test "selected_ids override filters: only selected members exported when filters also set", %{
+      conn: conn,
+      member1: m1,
+      member2: m2,
+      member3: _m3
+    } do
+      # When selected_ids is set, cycle_status_filter and boolean_filters must not reduce the set:
+      # only the selected members are exported.
+      payload = %{
+        "selected_ids" => [m1.id, m2.id],
+        "member_fields" => ["first_name", "last_name", "email"],
+        "custom_field_ids" => [],
+        "query" => nil,
+        "sort_field" => nil,
+        "sort_order" => nil,
+        "cycle_status_filter" => "paid",
+        "boolean_filters" => %{}
+      }
+
+      conn = get(conn, "/members")
+      csrf_token = csrf_token_from_conn(conn)
+
+      conn =
+        post(conn, "/members/export.csv", %{
+          "payload" => Jason.encode!(payload),
+          "_csrf_token" => csrf_token
+        })
+
+      assert conn.status == 200
+      body = response(conn, 200)
+      lines = export_lines(body)
+
+      assert length(lines) == 3
+      assert body =~ "Alice"
+      assert body =~ "Bob"
+      refute body =~ "Carol"
+    end
+
+    test "cycle_status_filter applied when export all returns CSV", %{
+      conn: conn,
+      member1: _m1,
+      member2: _m2,
+      member3: _m3
+    } do
+      payload = %{
+        "selected_ids" => [],
+        "member_fields" => ["first_name", "email"],
+        "custom_field_ids" => [],
+        "query" => nil,
+        "sort_field" => nil,
+        "sort_order" => nil,
+        "cycle_status_filter" => "paid",
+        "show_current_cycle" => true
+      }
+
+      conn = get(conn, "/members")
+      csrf_token = csrf_token_from_conn(conn)
+
+      conn =
+        post(conn, "/members/export.csv", %{
+          "payload" => Jason.encode!(payload),
+          "_csrf_token" => csrf_token
+        })
+
+      assert conn.status == 200
+      assert get_resp_header(conn, "content-type") |> List.first() =~ "text/csv"
+      body = response(conn, 200)
+      lines = export_lines(body)
+      assert length(lines) >= 1
+      assert hd(lines) =~ "First Name"
+    end
+
     test "filters out unknown member fields from export", %{conn: conn, member1: m1} do
       payload = %{
         "selected_ids" => [m1.id],
@@ -607,6 +679,70 @@ defmodule MvWeb.MemberExportControllerTest do
       refute body =~ member_with_integer.last_name
       refute body =~ member_without_value.last_name
     end
+
+    test "boolean_filters accept string true/false from query encoding", %{
+      conn: conn,
+      boolean_field: boolean_field,
+      member_with_boolean: member_with_boolean
+    } do
+      payload = %{
+        "selected_ids" => [],
+        "member_fields" => ["first_name", "last_name"],
+        "custom_field_ids" => [boolean_field.id],
+        "query" => nil,
+        "sort_field" => nil,
+        "sort_order" => nil,
+        "boolean_filters" => %{to_string(boolean_field.id) => "true"}
+      }
+
+      conn = get(conn, "/members")
+      csrf_token = csrf_token_from_conn(conn)
+
+      conn =
+        post(conn, "/members/export.csv", %{
+          "payload" => Jason.encode!(payload),
+          "_csrf_token" => csrf_token
+        })
+
+      assert conn.status == 200
+      body = response(conn, 200)
+      assert body =~ member_with_boolean.last_name
+    end
+
+    test "combination cycle_status_filter and boolean_filters applied when export all", %{
+      conn: conn,
+      boolean_field: boolean_field,
+      member_with_boolean: _member_with_boolean
+    } do
+      # Both filters are applied (AND). Export returns 200 and valid CSV.
+      payload = %{
+        "selected_ids" => [],
+        "member_fields" => ["first_name", "last_name"],
+        "custom_field_ids" => [boolean_field.id],
+        "query" => nil,
+        "sort_field" => nil,
+        "sort_order" => nil,
+        "cycle_status_filter" => "paid",
+        "show_current_cycle" => true,
+        "boolean_filters" => %{to_string(boolean_field.id) => true}
+      }
+
+      conn = get(conn, "/members")
+      csrf_token = csrf_token_from_conn(conn)
+
+      conn =
+        post(conn, "/members/export.csv", %{
+          "payload" => Jason.encode!(payload),
+          "_csrf_token" => csrf_token
+        })
+
+      assert conn.status == 200
+      assert get_resp_header(conn, "content-type") |> List.first() =~ "text/csv"
+      body = response(conn, 200)
+      lines = export_lines(body)
+      assert length(lines) >= 1
+      assert hd(lines) =~ "First Name"
+    end
   end
 
   describe "POST /members/export.pdf" do