diff --git a/drivers/SmartThings/matter-lock/src/new-matter-lock/init.lua b/drivers/SmartThings/matter-lock/src/new-matter-lock/init.lua
index 670b9dc63b..3850d71380 100644
--- a/drivers/SmartThings/matter-lock/src/new-matter-lock/init.lua
+++ b/drivers/SmartThings/matter-lock/src/new-matter-lock/init.lua
@@ -1671,6 +1671,7 @@ local function handle_update_credential(driver, device, command)
   device:set_field(lock_utils.COMMAND_NAME, cmdName, {persist = true})
   device:set_field(lock_utils.USER_INDEX, userIdx, {persist = true})
   device:set_field(lock_utils.CRED_INDEX, credIdx, {persist = true})
+  device:set_field(lock_utils.USER_TYPE, nil, {persist = true})
 
   -- Send command
   local ep = device:component_to_endpoint(command.component)
@@ -1728,7 +1729,7 @@ local function set_pin_response_handler(driver, device, ib, response)
     -- If User Type is Guest and device support schedule, add default schedule
     local week_schedule_eps = device:get_endpoints(DoorLock.ID, {feature_bitmap = DoorLock.types.Feature.WEEK_DAY_ACCESS_SCHEDULES})
     local year_schedule_eps = device:get_endpoints(DoorLock.ID, {feature_bitmap = DoorLock.types.Feature.YEAR_DAY_ACCESS_SCHEDULES})
-    if userType == "guest" and (#week_schedule_eps > 0 or #year_schedule_eps > 0) then
+    if userType == "guest" and (#week_schedule_eps > 0 or #year_schedule_eps > 0) and cmdName ~= "updateCredential" then
       local cmdName = "defaultSchedule"
       local scheduleIdx = 1
 
diff --git a/drivers/SmartThings/matter-lock/src/test/test_new_matter_lock.lua b/drivers/SmartThings/matter-lock/src/test/test_new_matter_lock.lua
index 0b7535223b..492a3c2805 100644
--- a/drivers/SmartThings/matter-lock/src/test/test_new_matter_lock.lua
+++ b/drivers/SmartThings/matter-lock/src/test/test_new_matter_lock.lua
@@ -1666,15 +1666,106 @@ test.register_coroutine_test(
 )
 
 test.register_coroutine_test(
-  "Handle Update Credential command received from SmartThings.",
+  "Update Credential for Guest user should not add default schedule again",
   function()
+    -- Add Guest user with credential. This sets the USER_TYPE field to "guest".
+    test.socket.capability:__queue_receive(
+      {
+        mock_device.id,
+        {
+          capability = capabilities.lockCredentials.ID,
+          command = "addCredential",
+          args = {0, "guest", "pin", "654123"}
+        },
+      }
+    )
+    test.socket.matter:__expect_send(
+      {
+        mock_device.id,
+        DoorLock.server.commands.SetCredential(
+          mock_device, 1, -- endpoint
+          DoorLock.types.DataOperationTypeEnum.ADD, -- operation_type
+          DoorLock.types.CredentialStruct(
+            {credential_type = DoorLock.types.CredentialTypeEnum.PIN, credential_index = 1}
+          ), -- credential
+          "654123", -- credential_data
+          nil, -- user_index
+          nil, -- user_status
+          DoorLock.types.UserTypeEnum.SCHEDULE_RESTRICTED_USER -- user_type
+        ),
+      }
+    )
+    test.wait_for_events()
+    test.socket.matter:__queue_receive(
+      {
+        mock_device.id,
+        DoorLock.client.commands.SetCredentialResponse:build_test_command_response(
+          mock_device, 1,
+          DoorLock.types.DlStatus.SUCCESS, -- status
+          1, -- user_index
+          2 -- next_credential_index
+        ),
+      }
+    )
+    test.socket.capability:__expect_send(
+      mock_device:generate_test_message(
+        "main",
+        capabilities.lockUsers.users(
+          {{userIndex = 1, userType = "guest"}},
+          {visibility={displayed=false}}
+        )
+      )
+    )
+    test.socket.capability:__expect_send(
+      mock_device:generate_test_message(
+        "main",
+        capabilities.lockCredentials.credentials(
+          {{credentialIndex=1, credentialType="pin", userIndex=1}},
+          {visibility={displayed=false}}
+        )
+      )
+    )
+    test.socket.matter:__expect_send(
+      {
+        mock_device.id,
+        DoorLock.server.commands.SetYearDaySchedule(
+          mock_device, 1, -- endpoint
+          1, -- year_day_index
+          1, -- user_index
+          0, -- local_start_time
+          0xffffffff -- local_end_time
+        ),
+      }
+    )
+    test.wait_for_events()
+    test.socket.matter:__queue_receive(
+      {
+        mock_device.id,
+        DoorLock.server.commands.SetYearDaySchedule:build_test_command_response(
+          mock_device, 1,
+          DoorLock.types.DlStatus.SUCCESS -- status
+        ),
+      }
+    )
+    test.socket.capability:__expect_send(
+      mock_device:generate_test_message(
+        "main",
+        capabilities.lockCredentials.commandResult(
+          {commandName="addCredential", credentialIndex=1, statusCode="success", userIndex=1},
+          {state_change=true, visibility={displayed=false}}
+        )
+      )
+    )
+    test.wait_for_events()
+    -- Update the Guest user's credential. The stale "guest" USER_TYPE field must
+    -- be cleared so the default schedule is not added again on the response.
     test.socket.capability:__queue_receive(
       {
         mock_device.id,
         {
           capability = capabilities.lockCredentials.ID,
           command = "updateCredential",
-          args = {1, 1, "pin", "654123"}
+          args = {1, 1, "pin", "111213"}
         },
       }
     )
@@ -1687,7 +1778,7 @@ test.register_coroutine_test(
           DoorLock.types.CredentialStruct(
             {credential_type = DoorLock.types.CredentialTypeEnum.PIN, credential_index = 1}
           ), -- credential
-          "654123", -- credential_data
+          "111213", -- credential_data
           1, -- user_index
           nil, -- user_status
           nil -- user_type
@@ -1706,6 +1797,7 @@ test.register_coroutine_test(
         ),
       }
     )
+    -- The commandResult must be emitted without sending SetYearDaySchedule
     test.socket.capability:__expect_send(
       mock_device:generate_test_message(
         "main",