diff --git a/buffet/buffet_client.cc b/buffet/buffet_client.cc
index 635c037..bde5abe 100644
--- a/buffet/buffet_client.cc
+++ b/buffet/buffet_client.cc
@@ -42,8 +42,7 @@
   std::cerr << "  " << kManagerGetDeviceInfo << std::endl;
   std::cerr << "  " << kManagerStartRegisterDevice
                     << " param1 = val1&param2 = val2..." << std::endl;
-  std::cerr << "  " << kManagerFinishRegisterDevice
-                    << " device_id" << std::endl;
+  std::cerr << "  " << kManagerFinishRegisterDevice << std::endl;
   std::cerr << "  " << kManagerAddCommand
                     << " '{\"name\":\"command_name\",\"parameters\":{}}'"
                     << std::endl;
@@ -176,7 +175,7 @@
   }
 
   int CallManagerFinishRegisterDevice(const CommandLine::StringVector& args) {
-    if (args.size() > 1) {
+    if (args.size() > 0) {
       std::cerr << "Invalid number of arguments for "
                 << "Manager." << kManagerFinishRegisterDevice << std::endl;
       usage();
@@ -185,13 +184,11 @@
 
     ErrorPtr error;
     std::string user_auth_code;
-    if (!args.empty()) { user_auth_code = args.front(); }
     static const int timeout_ms = 10000;
     auto response = CallMethodAndBlockWithTimeout(
         timeout_ms,
         manager_proxy_,
-        kManagerInterface, kManagerFinishRegisterDevice, &error,
-        user_auth_code);
+        kManagerInterface, kManagerFinishRegisterDevice, &error);
     std::string device_id;
     if (!response ||
         !ExtractMethodCallResults(response.get(), &error, &device_id)) {
diff --git a/buffet/device_registration_info.cc b/buffet/device_registration_info.cc
index 3e35cec..925307d 100644
--- a/buffet/device_registration_info.cc
+++ b/buffet/device_registration_info.cc
@@ -374,16 +374,15 @@
   req_json.Set("deviceDraft.commandDefs", commands.release());
   req_json.Set("deviceDraft.state", state.release());
 
-  int status_code{0};
   auto url = GetServiceURL("registrationTickets/" + ticket_id_,
                            {{"key", api_key_}});
-  auto resp_json = chromeos::http::ParseJsonResponse(
-      chromeos::http::PatchJson(url, &req_json, transport_, error).get(),
-      &status_code, error);
-  if (!resp_json)
+  std::unique_ptr<chromeos::http::Response> response =
+      chromeos::http::PatchJson(url, &req_json, transport_, error);
+  auto json_resp = chromeos::http::ParseJsonResponse(response.get(), nullptr,
+                                                     error);
+  if (!json_resp)
     return std::string();
-
-  if (status_code >= chromeos::http::status_code::BadRequest)
+  if (!response->IsSuccessful())
     return std::string();
 
   std::string auth_url = GetOAuthURL("auth", {
@@ -402,8 +401,7 @@
   return ret;
 }
 
-bool DeviceRegistrationInfo::FinishRegistration(
-    const std::string& user_auth_code, chromeos::ErrorPtr* error) {
+bool DeviceRegistrationInfo::FinishRegistration(chromeos::ErrorPtr* error) {
   if (ticket_id_.empty()) {
     LOG(ERROR) << "Finish registration without ticket ID";
     chromeos::Error::AddTo(error, kErrorDomainBuffet,
@@ -412,48 +410,10 @@
     return false;
   }
 
-  std::string url = GetServiceURL("registrationTickets/" + ticket_id_);
-  std::unique_ptr<chromeos::http::Response> response;
-  if (!user_auth_code.empty()) {
-    response = chromeos::http::PostFormData(GetOAuthURL("token"), {
-      {"code", user_auth_code},
-      {"client_id", client_id_},
-      {"client_secret", client_secret_},
-      {"redirect_uri", "urn:ietf:wg:oauth:2.0:oob"},
-      {"grant_type", "authorization_code"}
-    }, transport_, error);
-    if (!response)
-      return false;
-
-    auto json_resp = ParseOAuthResponse(response.get(), error);
-    if (!json_resp)
-      return false;
-
-    std::string user_access_token;
-    std::string token_type;
-    if (!json_resp->GetString("access_token", &user_access_token) ||
-        !json_resp->GetString("token_type", &token_type)) {
-      chromeos::Error::AddTo(error, kErrorDomainOAuth2, "unexpected_response",
-                             "User access_token is missing in response");
-      return false;
-    }
-
-    base::DictionaryValue user_info;
-    user_info.SetString("userEmail", "me");
-    response = chromeos::http::PatchJson(
-        url, &user_info, {BuildAuthHeader(token_type, user_access_token)},
-        transport_, error);
-
-    auto json = chromeos::http::ParseJsonResponse(response.get(), nullptr,
-                                                  error);
-    if (!json)
-      return false;
-  }
-
-  std::string auth_code;
-  url += "/finalize?key=" + api_key_;
-  LOG(INFO) << "Sending request to: " << url;
-  response = chromeos::http::PostBinary(url, nullptr, 0, transport_, error);
+  std::string url = GetServiceURL("registrationTickets/" + ticket_id_ +
+                                  "/finalize?key=" + api_key_);
+  std::unique_ptr<chromeos::http::Response> response =
+      chromeos::http::PostBinary(url, nullptr, 0, transport_, error);
   if (!response)
     return false;
   auto json_resp = chromeos::http::ParseJsonResponse(response.get(), nullptr,
@@ -464,6 +424,8 @@
     ParseGCDError(json_resp.get(), error);
     return false;
   }
+
+  std::string auth_code;
   if (!json_resp->GetString("robotAccountEmail", &device_robot_account_) ||
       !json_resp->GetString("robotAccountAuthorizationCode", &auth_code) ||
       !json_resp->GetString("deviceDraft.id", &device_id_)) {
diff --git a/buffet/device_registration_info.h b/buffet/device_registration_info.h
index 117f891..bd2159f 100644
--- a/buffet/device_registration_info.h
+++ b/buffet/device_registration_info.h
@@ -97,18 +97,15 @@
   // Starts device registration procedure. |params| are a list of
   // key-value pairs of device information, such as client_id, client_secret,
   // and so on. If a particular key-value pair is omitted, a default value
-  // is used when possible. Returns a device claim ID on success.
+  // is used when possible. Returns a device registration ticket ID on success.
   // The values are all strings for now.
   std::string StartRegistration(
     const std::map<std::string, std::string>& params,
     chromeos::ErrorPtr* error);
 
-  // Finalizes the device registration. If |user_auth_code| is provided, then
-  // the device record is populated with user email on user's behalf. Otherwise
-  // the user is responsible to issue a PATCH request to provide a valid
-  // email address before calling FinishRegistration.
-  bool FinishRegistration(const std::string& user_auth_code,
-                          chromeos::ErrorPtr* error);
+  // Finalizes the device registration.
+  // StartRegistration must have been invoked before.
+  bool FinishRegistration(chromeos::ErrorPtr* error);
 
  private:
   // Saves the device registration to cache.
diff --git a/buffet/device_registration_info_unittest.cc b/buffet/device_registration_info_unittest.cc
index d61f502..e33630f 100644
--- a/buffet/device_registration_info_unittest.cc
+++ b/buffet/device_registration_info_unittest.cc
@@ -370,7 +370,7 @@
 
   storage_->reset_save_count();
   DeviceRegistrationInfo::TestHelper::SetTestTicketId(dev_reg_.get());
-  EXPECT_TRUE(dev_reg_->FinishRegistration("", nullptr));
+  EXPECT_TRUE(dev_reg_->FinishRegistration(nullptr));
   EXPECT_EQ(1,
             storage_->save_count());  // The device info must have been saved.
   EXPECT_EQ(2, transport_->GetRequestCount());
@@ -398,55 +398,4 @@
   EXPECT_EQ(test_data::kServiceURL, value);
 }
 
-TEST_F(DeviceRegistrationInfoTest, FinishRegistration_Auth) {
-  // Test finalizing ticket with user authorization token.
-  EXPECT_TRUE(dev_reg_->Load());
-
-  // General ticket finalization handler.
-  std::string ticket_url =
-      dev_reg_->GetServiceURL("registrationTickets/" +
-                             std::string(test_data::kClaimTicketId));
-  transport_->AddHandler(ticket_url + "/finalize",
-                         chromeos::http::request_type::kPost,
-                         base::Bind(FinalizeTicketHandler));
-
-  transport_->AddHandler(dev_reg_->GetOAuthURL("token"),
-                         chromeos::http::request_type::kPost,
-                         base::Bind(OAuth2Handler));
-
-  // Handle patching in the user email onto the device record.
-  auto email_patch_handler = [](const ServerRequest& request,
-                                ServerResponse* response) {
-    std::string auth_header = "Bearer ";
-    auth_header += test_data::kUserAccessToken;
-    EXPECT_EQ(auth_header,
-        request.GetHeader(chromeos::http::request_header::kAuthorization));
-    auto json = request.GetDataAsJson();
-    EXPECT_NE(nullptr, json.get());
-    std::string value;
-    EXPECT_TRUE(json->GetString("userEmail", &value));
-    EXPECT_EQ("me", value);
-
-    response->ReplyJson(chromeos::http::status_code::Ok, {
-      {"id", test_data::kClaimTicketId},
-      {"kind", "clouddevices#registrationTicket"},
-      {"oauthClientId", test_data::kClientId},
-      {"userEmail", "user@email.com"},
-      {"deviceDraft.id", test_data::kDeviceId},
-      {"deviceDraft.kind", "clouddevices#device"},
-      {"deviceDraft.channel.supportedType", "xmpp"},
-    });
-  };
-  transport_->AddHandler(ticket_url, chromeos::http::request_type::kPatch,
-                         base::Bind(email_patch_handler));
-
-  storage_->reset_save_count();
-  DeviceRegistrationInfo::TestHelper::SetTestTicketId(dev_reg_.get());
-  EXPECT_TRUE(dev_reg_->FinishRegistration(test_data::kUserAccountAuthCode,
-                                          nullptr));
-  EXPECT_EQ(1,
-            storage_->save_count());  // The device info must have been saved.
-  EXPECT_EQ(4, transport_->GetRequestCount());
-}
-
 }  // namespace buffet
diff --git a/buffet/manager.cc b/buffet/manager.cc
index c39ec52..10d36cf 100644
--- a/buffet/manager.cc
+++ b/buffet/manager.cc
@@ -107,10 +107,9 @@
   return device_info_->StartRegistration(params, error);
 }
 
-std::string Manager::HandleFinishRegisterDevice(
-    chromeos::ErrorPtr* error, const std::string& user_auth_code) {
+std::string Manager::HandleFinishRegisterDevice(chromeos::ErrorPtr* error) {
   LOG(INFO) << "Received call to Manager.FinishRegisterDevice()";
-  if (!device_info_->FinishRegistration(user_auth_code, error))
+  if (!device_info_->FinishRegistration(error))
     return std::string();
 
   return device_info_->GetDeviceId(error);
diff --git a/buffet/manager.h b/buffet/manager.h
index a56b6c3..4648b95 100644
--- a/buffet/manager.h
+++ b/buffet/manager.h
@@ -52,8 +52,7 @@
                                         const std::map<std::string,
                                                        std::string>& params);
   // Handles calls to org.chromium.Buffet.Manager.FinishRegisterDevice().
-  std::string HandleFinishRegisterDevice(chromeos::ErrorPtr* error,
-                                         const std::string& user_auth_code);
+  std::string HandleFinishRegisterDevice(chromeos::ErrorPtr* error);
   // Handles calls to org.chromium.Buffet.Manager.UpdateState().
   void HandleUpdateState(chromeos::ErrorPtr* error,
                          const chromeos::VariantDictionary& property_set);