diff --git a/src/handlers/handler_calendar_by_id.erl b/src/handlers/handler_calendar_by_id.erl
index 52126e8..7919f59 100755
--- a/src/handlers/handler_calendar_by_id.erl
+++ b/src/handlers/handler_calendar_by_id.erl
@@ -154,6 +154,9 @@ update_calendar(Req) ->
               handler_utils:send_error(Req2, 402, <<"Subscription required for commercial calendar">>);
             {error, not_found} ->
               handler_utils:send_error(Req2, 404, <<"Calendar not found">>);
+            {error, {invalid_settings, Key}} when is_binary(Key) ->
+              handler_utils:send_error(Req2, 400,
+                <<"Invalid settings.", Key/binary>>);
             {error, _} ->
               handler_utils:send_error(Req2, 500, <<"Internal server error">>)
           end;
diff --git a/src/logic/logic_calendar.erl b/src/logic/logic_calendar.erl
index 9851fbd..7c5706c 100755
--- a/src/logic/logic_calendar.erl
+++ b/src/logic/logic_calendar.erl
@@ -4,6 +4,7 @@
 -export([create_calendar/3, create_calendar/4, create_calendar/5, get_calendar/2, list_calendars/1,
   update_calendar/3, delete_calendar/2, ensure_default_calendar/1]).
 -export([can_access/2, can_edit/2, booking_open/1]).
+-export([normalize_settings/1]).
 -export([admin_list_all/0, admin_get_by_id/1, admin_update/2, admin_delete/1]).
 
 %% Создание календаря с политикой по умолчанию (manual)
@@ -109,12 +110,16 @@ update_calendar(UserId, CalendarId, Updates) ->
     {ok, Calendar} ->
       case can_edit(UserId, Calendar) of
         true ->
-          ValidUpdates = validate_updates(Updates),
-          case gate_type_change(UserId, Calendar, ValidUpdates) of
+          case validate_updates(Updates) of
             {error, _} = Err ->
               Err;
-            {ok, ValidUpdates2} ->
-              apply_calendar_update(CalendarId, Calendar, ValidUpdates2)
+            {ok, ValidUpdates} ->
+              case gate_type_change(UserId, Calendar, ValidUpdates) of
+                {error, _} = Err ->
+                  Err;
+                {ok, ValidUpdates2} ->
+                  apply_calendar_update(CalendarId, Calendar, ValidUpdates2)
+              end
           end;
         false ->
           {error, access_denied}
@@ -225,24 +230,41 @@ can_edit(_UserId, #calendar{owner_id = _OwnerId}) ->
 can_edit(_, _) ->
   false.
 
-%% Валидация полей обновления
+%% Валидация полей обновления.
+%% Known settings keys with invalid shape → {error, {invalid_settings, Key}}.
+%% Unknown settings keys (e.g. week_patterns) are preserved as-is.
 validate_updates(Updates) ->
-  lists:filtermap(fun(U) ->
-    case normalize_update(U) of
-      false -> false;
-      Norm ->
-        case validate_update(Norm) of
-          true -> {true, Norm};
-          false -> false
-        end
-    end
-  end, Updates).
+  validate_updates(Updates, []).
+
+validate_updates([], Acc) ->
+  {ok, lists:reverse(Acc)};
+validate_updates([U | Rest], Acc) ->
+  case normalize_update(U) of
+    false ->
+      validate_updates(Rest, Acc);
+    {error, _} = Err ->
+      Err;
+    Norm ->
+      case validate_update(Norm) of
+        true -> validate_updates(Rest, [Norm | Acc]);
+        false -> validate_updates(Rest, Acc)
+      end
+  end.
 
 normalize_update({type, <<"personal">>}) -> {type, personal};
 normalize_update({type, <<"commercial">>}) -> {type, commercial};
 normalize_update({type, personal}) -> {type, personal};
 normalize_update({type, commercial}) -> {type, commercial};
-normalize_update({<<"settings">>, Value}) when is_map(Value) -> {settings, Value};
+normalize_update({<<"settings">>, Value}) when is_map(Value) ->
+  case normalize_settings(Value) of
+    {ok, Map} -> {settings, Map};
+    {error, _} = Err -> Err
+  end;
+normalize_update({settings, Value}) when is_map(Value) ->
+  case normalize_settings(Value) of
+    {ok, Map} -> {settings, Map};
+    {error, _} = Err -> Err
+  end;
 normalize_update({<<"title">>, Value}) when is_binary(Value) -> {title, Value};
 normalize_update({<<"description">>, Value}) when is_binary(Value) -> {description, Value};
 normalize_update({<<"tags">>, Value}) when is_list(Value) -> {tags, Value};
@@ -261,7 +283,7 @@ validate_update({short_name, Value}) when is_binary(Value) -> true;
 validate_update({category, Value}) when is_binary(Value) -> true;
 validate_update({color, Value}) when is_binary(Value) -> true;
 validate_update({image_url, Value}) when is_binary(Value) -> true;
-%% Opaque JSON object for client prefs (e.g. week_patterns for schedule fill).
+%% Documented org-default keys validated in normalize_settings/1; unknown keys passthrough.
 validate_update({settings, Value}) when is_map(Value) -> true;
 validate_update({confirmation, Value}) ->
   case Value of
@@ -272,6 +294,77 @@ validate_update({confirmation, Value}) ->
   end;
 validate_update(_) -> false.
 
+%%%-------------------------------------------------------------------
+%%% @doc Validate documented calendar.settings keys for org defaults.
+%%% Unknown keys are kept (forward-compat, e.g. week_patterns).
+%%% @end
+%%%-------------------------------------------------------------------
+-spec normalize_settings(map()) -> {ok, map()} | {error, {invalid_settings, binary()}}.
+normalize_settings(Map) when is_map(Map) ->
+  normalize_settings_keys(maps:keys(Map), Map).
+
+normalize_settings_keys([], Map) ->
+  {ok, Map};
+normalize_settings_keys([Key | Rest], Map) ->
+  case validate_settings_key(Key, maps:get(Key, Map)) of
+    ok ->
+      normalize_settings_keys(Rest, Map);
+    {error, _} = Err ->
+      Err
+  end.
+
+validate_settings_key(<<"default_location">>, Val) ->
+  validate_default_location(Val);
+validate_settings_key(<<"default_duration_minutes">>, Val) ->
+  validate_default_duration(Val);
+validate_settings_key(<<"default_recurrence">>, Val) ->
+  validate_default_recurrence(Val);
+validate_settings_key(_Unknown, _Val) ->
+  ok.
+
+validate_default_location(Loc) when is_map(Loc) ->
+  case maps:get(<<"address">>, Loc, undefined) of
+    Address when is_binary(Address), byte_size(Address) > 0 ->
+      HasLat = maps:is_key(<<"lat">>, Loc),
+      HasLon = maps:is_key(<<"lon">>, Loc),
+      case {HasLat, HasLon} of
+        {false, false} ->
+          ok;
+        {true, true} ->
+          Lat = maps:get(<<"lat">>, Loc),
+          Lon = maps:get(<<"lon">>, Loc),
+          case is_number(Lat) andalso is_number(Lon) of
+            true -> ok;
+            false -> {error, {invalid_settings, <<"default_location">>}}
+          end;
+        _ ->
+          {error, {invalid_settings, <<"default_location">>}}
+      end;
+    _ ->
+      {error, {invalid_settings, <<"default_location">>}}
+  end;
+validate_default_location(_) ->
+  {error, {invalid_settings, <<"default_location">>}}.
+
+validate_default_duration(N) when is_integer(N), N >= 1, N =< 1440 ->
+  ok;
+validate_default_duration(_) ->
+  {error, {invalid_settings, <<"default_duration_minutes">>}}.
+
+validate_default_recurrence(null) ->
+  ok;
+validate_default_recurrence(Rec) when is_map(Rec) ->
+  Enabled = maps:get(<<"enabled">>, Rec, undefined),
+  Freq = maps:get(<<"freq">>, Rec, undefined),
+  Interval = maps:get(<<"interval">>, Rec, undefined),
+  ValidFreq = Freq =:= <<"DAILY">> orelse Freq =:= <<"WEEKLY">> orelse Freq =:= <<"MONTHLY">>,
+  case is_boolean(Enabled) andalso ValidFreq andalso is_integer(Interval) andalso Interval >= 1 of
+    true -> ok;
+    false -> {error, {invalid_settings, <<"default_recurrence">>}}
+  end;
+validate_default_recurrence(_) ->
+  {error, {invalid_settings, <<"default_recurrence">>}}.
+
 %% ─── Административные функции ────────────────────────────────────────
 -spec admin_list_all() -> {ok, [map()]} | {error, term()}.
 admin_list_all() ->
diff --git a/test/api/users/user_calendar_by_id_tests.erl b/test/api/users/user_calendar_by_id_tests.erl
index bccfe17..bb9d296 100644
--- a/test/api/users/user_calendar_by_id_tests.erl
+++ b/test/api/users/user_calendar_by_id_tests.erl
@@ -62,7 +62,7 @@ test_update_calendar(Token, CalId) ->
   ct:pal("    OK").
 
 test_update_calendar_settings(Token, CalId) ->
-  ct:pal("  TEST: Persist calendar.settings.week_patterns"),
+  ct:pal("  TEST: Persist calendar.settings week_patterns + org defaults"),
   Path = <<"/v1/calendars/", CalId/binary>>,
   Settings = #{
     <<"week_patterns">> => [
@@ -73,12 +73,26 @@ test_update_calendar_settings(Token, CalId) ->
           #{<<"weekday">> => 1, <<"time">> => <<"10:00">>, <<"duration">> => 60, <<"title">> => <<"Open">>}
         ]
       }
-    ]
+    ],
+    <<"default_location">> => #{
+      <<"address">> => <<"ул. Пример, 1">>,
+      <<"lat">> => 55.75,
+      <<"lon">> => 37.61
+    },
+    <<"default_duration_minutes">> => 60,
+    <<"default_recurrence">> => #{
+      <<"enabled">> => true,
+      <<"freq">> => <<"WEEKLY">>,
+      <<"interval">> => 1
+    }
   },
   Updated = api_test_runner:client_put(Path, Token, #{settings => Settings}),
   ?assertEqual(Settings, maps:get(<<"settings">>, Updated)),
   Got = api_test_runner:client_get(Path, Token),
   ?assertEqual(Settings, maps:get(<<"settings">>, Got)),
+  Bad = api_test_runner:client_request(put, Path, Token,
+    jsx:encode(#{settings => #{default_location => #{address => <<"">>}}})),
+  ?assertMatch({ok, 400, _, _}, Bad),
   ct:pal("    OK").
 
 test_update_calendar_forbidden(OtherToken, CalId) ->
diff --git a/test/unit/logic_calendar_tests.erl b/test/unit/logic_calendar_tests.erl
index da36a1a..f9a31ca 100755
--- a/test/unit/logic_calendar_tests.erl
+++ b/test/unit/logic_calendar_tests.erl
@@ -37,6 +37,8 @@ logic_calendar_test_() ->
       {"Update calendar test", fun test_update_calendar/0},
       {"Persist calendar settings (week_patterns)", fun test_update_settings/0},
       {"Reject non-map settings", fun test_update_settings_invalid/0},
+      {"Org defaults settings round-trip", fun test_update_settings_org_defaults/0},
+      {"Reject invalid default_location shape", fun test_update_settings_invalid_location/0},
       {"Delete calendar test", fun test_delete_calendar/0},
       {"Access control test", fun test_access_control/0},
       {"Ensure default calendar test", fun test_ensure_default_calendar/0}
@@ -152,6 +154,66 @@ test_update_settings_invalid() ->
     UserId, Calendar#calendar.id, [{settings, [<<"not-a-map">>]}]),
   ?assertEqual(#{}, Same#calendar.settings).
 
+test_update_settings_org_defaults() ->
+  UserId = create_test_user(),
+  {ok, Calendar} = logic_calendar:create_calendar(UserId, <<"Salon">>, <<"">>, manual),
+  Patterns = [
+    #{
+      <<"id">> => <<"p1">>,
+      <<"name">> => <<"Weekdays">>,
+      <<"slots">> => [
+        #{<<"weekday">> => 1, <<"time">> => <<"10:00">>, <<"duration">> => 60}
+      ]
+    }
+  ],
+  Settings = #{
+    <<"week_patterns">> => Patterns,
+    <<"default_location">> => #{
+      <<"address">> => <<"ул. Пример, 1">>,
+      <<"lat">> => 55.75,
+      <<"lon">> => 37.61
+    },
+    <<"default_duration_minutes">> => 90,
+    <<"default_recurrence">> => #{
+      <<"enabled">> => true,
+      <<"freq">> => <<"WEEKLY">>,
+      <<"interval">> => 1
+    }
+  },
+  {ok, Updated} = logic_calendar:update_calendar(
+    UserId, Calendar#calendar.id, [{settings, Settings}]),
+  ?assertEqual(Settings, Updated#calendar.settings),
+  {ok, Reloaded} = logic_calendar:get_calendar(UserId, Calendar#calendar.id),
+  ?assertEqual(Settings, Reloaded#calendar.settings),
+  %% null clears recurrence default
+  Settings2 = Settings#{<<"default_recurrence">> => null},
+  {ok, Updated2} = logic_calendar:update_calendar(
+    UserId, Calendar#calendar.id, [{settings, Settings2}]),
+  ?assertEqual(null, maps:get(<<"default_recurrence">>, Updated2#calendar.settings)).
+
+test_update_settings_invalid_location() ->
+  UserId = create_test_user(),
+  {ok, Calendar} = logic_calendar:create_calendar(UserId, <<"Salon">>, <<"">>, manual),
+  ?assertMatch({error, {invalid_settings, <<"default_location">>}},
+    logic_calendar:update_calendar(UserId, Calendar#calendar.id, [
+      {settings, #{<<"default_location">> => #{<<"address">> => <<"">>}}}
+    ])),
+  ?assertMatch({error, {invalid_settings, <<"default_location">>}},
+    logic_calendar:update_calendar(UserId, Calendar#calendar.id, [
+      {settings, #{<<"default_location">> => #{<<"address">> => <<"X">>, <<"lat">> => 1}}}
+    ])),
+  ?assertMatch({error, {invalid_settings, <<"default_duration_minutes">>}},
+    logic_calendar:update_calendar(UserId, Calendar#calendar.id, [
+      {settings, #{<<"default_duration_minutes">> => 0}}
+    ])),
+  ?assertEqual(#{},
+    begin
+      {ok, Same} = logic_calendar:get_calendar(UserId, Calendar#calendar.id),
+      Same#calendar.settings
+    end),
+  ?assertMatch({error, {invalid_settings, <<"default_location">>}},
+    logic_calendar:normalize_settings(#{<<"default_location">> => <<"street">>})).
+
 test_delete_calendar() ->
   UserId = create_test_user(),
   {ok, Calendar} = logic_calendar:create_calendar(UserId, <<"Test">>, <<"">>, manual),