diff --git a/src/core/libraries/app_content/app_content.cpp b/src/core/libraries/app_content/app_content.cpp
index 1523c2703..a5952c7ea 100644
--- a/src/core/libraries/app_content/app_content.cpp
+++ b/src/core/libraries/app_content/app_content.cpp
@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: Copyright 2024 shadPS4 Emulator Project
+// SPDX-FileCopyrightText: Copyright 2024-2026 shadPS4 Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #include <cmath>
@@ -345,7 +345,7 @@ int PS4_SYSV_ABI sceAppContentInitialize(const OrbisAppContentInitParam* initPar
     if (addcont_count > 0) {
         SystemService::OrbisSystemServiceEvent event{};
         event.event_type = SystemService::OrbisSystemServiceEventType::EntitlementUpdate;
-        event.service_entitlement_update.user_id = 0;
+        event.service_entitlement_update.userId = 0;
         event.service_entitlement_update.np_service_label = 0;
         SystemService::PushSystemServiceEvent(event);
     }
diff --git a/src/core/libraries/audio3d/audio3d.cpp b/src/core/libraries/audio3d/audio3d.cpp
index 2ddbcd890..3f5fdcf78 100644
--- a/src/core/libraries/audio3d/audio3d.cpp
+++ b/src/core/libraries/audio3d/audio3d.cpp
@@ -29,10 +29,10 @@ s32 PS4_SYSV_ABI sceAudio3dAudioOutClose(const s32 handle) {
     return AudioOut::sceAudioOutClose(handle);
 }
 
-s32 PS4_SYSV_ABI
-sceAudio3dAudioOutOpen(const OrbisAudio3dPortId port_id, const OrbisUserServiceUserId user_id,
-                       s32 type, const s32 index, const u32 len, const u32 freq,
-                       const AudioOut::OrbisAudioOutParamExtendedInformation param) {
+s32 PS4_SYSV_ABI sceAudio3dAudioOutOpen(
+    const OrbisAudio3dPortId port_id, const Libraries::UserService::OrbisUserServiceUserId user_id,
+    s32 type, const s32 index, const u32 len, const u32 freq,
+    const AudioOut::OrbisAudioOutParamExtendedInformation param) {
     LOG_INFO(Lib_Audio3d,
              "called, port_id = {}, user_id = {}, type = {}, index = {}, len = {}, freq = {}",
              port_id, user_id, type, index, len, freq);
@@ -422,7 +422,7 @@ s32 PS4_SYSV_ABI sceAudio3dPortGetStatus() {
     return ORBIS_OK;
 }
 
-s32 PS4_SYSV_ABI sceAudio3dPortOpen(const OrbisUserServiceUserId user_id,
+s32 PS4_SYSV_ABI sceAudio3dPortOpen(const Libraries::UserService::OrbisUserServiceUserId user_id,
                                     const OrbisAudio3dOpenParameters* parameters,
                                     OrbisAudio3dPortId* port_id) {
     LOG_INFO(Lib_Audio3d, "called, user_id = {}, parameters = {}, id = {}", user_id,
diff --git a/src/core/libraries/audio3d/audio3d.h b/src/core/libraries/audio3d/audio3d.h
index 1057c1f31..ae20e39a8 100644
--- a/src/core/libraries/audio3d/audio3d.h
+++ b/src/core/libraries/audio3d/audio3d.h
@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: Copyright 2025 shadPS4 Emulator Project
+// SPDX-FileCopyrightText: Copyright 2025-2026 shadPS4 Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #pragma once
@@ -15,8 +15,6 @@ class SymbolsResolver;
 
 namespace Libraries::Audio3d {
 
-using OrbisUserServiceUserId = s32;
-
 enum class OrbisAudio3dRate : u32 {
     ORBIS_AUDIO3D_RATE_48000 = 0,
 };
@@ -91,7 +89,8 @@ struct Audio3dState {
 };
 
 s32 PS4_SYSV_ABI sceAudio3dAudioOutClose(s32 handle);
-s32 PS4_SYSV_ABI sceAudio3dAudioOutOpen(OrbisAudio3dPortId port_id, OrbisUserServiceUserId user_id,
+s32 PS4_SYSV_ABI sceAudio3dAudioOutOpen(OrbisAudio3dPortId port_id,
+                                        Libraries::UserService::OrbisUserServiceUserId user_id,
                                         s32 type, s32 index, u32 len, u32 freq,
                                         AudioOut::OrbisAudioOutParamExtendedInformation param);
 s32 PS4_SYSV_ABI sceAudio3dAudioOutOutput(s32 handle, void* ptr);
@@ -127,7 +126,7 @@ s32 PS4_SYSV_ABI sceAudio3dPortGetQueueLevel(OrbisAudio3dPortId port_id, u32* qu
                                              u32* queue_available);
 s32 PS4_SYSV_ABI sceAudio3dPortGetState();
 s32 PS4_SYSV_ABI sceAudio3dPortGetStatus();
-s32 PS4_SYSV_ABI sceAudio3dPortOpen(OrbisUserServiceUserId user_id,
+s32 PS4_SYSV_ABI sceAudio3dPortOpen(Libraries::UserService::OrbisUserServiceUserId user_id,
                                     const OrbisAudio3dOpenParameters* parameters,
                                     OrbisAudio3dPortId* port_id);
 s32 PS4_SYSV_ABI sceAudio3dPortPush(OrbisAudio3dPortId port_id, OrbisAudio3dBlocking blocking);
diff --git a/src/core/libraries/companion/companion_httpd.cpp b/src/core/libraries/companion/companion_httpd.cpp
index a8756c4cd..6ffc8c052 100644
--- a/src/core/libraries/companion/companion_httpd.cpp
+++ b/src/core/libraries/companion/companion_httpd.cpp
@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: Copyright 2024 shadPS4 Emulator Project
+// SPDX-FileCopyrightText: Copyright 2024-2026 shadPS4 Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #include "common/logging/log.h"
@@ -16,7 +16,7 @@ s32 PS4_SYSV_ABI sceCompanionHttpdAddHeader(const char* key, const char* value,
 }
 
 s32 PS4_SYSV_ABI
-sceCompanionHttpdGet2ndScreenStatus(Libraries::UserService::OrbisUserServiceUserId) {
+sceCompanionHttpdGet2ndScreenStatus(Libraries::UserService::OrbisUserServiceUserId userId) {
     LOG_ERROR(Lib_CompanionHttpd, "(STUBBED) called");
     return ORBIS_OK;
 }
diff --git a/src/core/libraries/game_live_streaming/gamelivestreaming.h b/src/core/libraries/game_live_streaming/gamelivestreaming.h
index 0bab969bd..5ceee8ff5 100644
--- a/src/core/libraries/game_live_streaming/gamelivestreaming.h
+++ b/src/core/libraries/game_live_streaming/gamelivestreaming.h
@@ -1,9 +1,10 @@
-// SPDX-FileCopyrightText: Copyright 2024 shadPS4 Emulator Project
+// SPDX-FileCopyrightText: Copyright 2024-2026 shadPS4 Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #pragma once
 
 #include "common/types.h"
+#include "core/libraries/system/userservice.h"
 
 namespace Core::Loader {
 class SymbolsResolver;
@@ -15,11 +16,11 @@ struct OrbisGameLiveStreamingStatus {
     bool isOnAir;
     u8 align[3];
     u32 spectatorCounts;
-    s32 userId;
+    Libraries::UserService::OrbisUserServiceUserId userId;
     u8 reserved[60];
 };
 struct OrbisGameLiveStreamingStatus2 {
-    s32 userId;
+    Libraries::UserService::OrbisUserServiceUserId userId;
     bool isOnAir;
     u8 align[3];
     u32 spectatorCounts;
diff --git a/src/core/libraries/np/np_auth.h b/src/core/libraries/np/np_auth.h
index 636210772..0894bd85d 100644
--- a/src/core/libraries/np/np_auth.h
+++ b/src/core/libraries/np/np_auth.h
@@ -1,10 +1,11 @@
-// SPDX-FileCopyrightText: Copyright 2025 shadPS4 Emulator Project
+// SPDX-FileCopyrightText: Copyright 2025-2026 shadPS4 Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #pragma once
 
 #include "common/types.h"
 #include "core/libraries/np/np_types.h"
+#include "core/libraries/system/userservice.h"
 
 namespace Core::Loader {
 class SymbolsResolver;
@@ -31,7 +32,7 @@ struct OrbisNpAuthGetAuthorizationCodeParameter {
 
 struct OrbisNpAuthGetAuthorizationCodeParameterA {
     u64 size;
-    s32 user_id;
+    Libraries::UserService::OrbisUserServiceUserId user_id;
     u8 padding[4];
     const OrbisNpClientId* client_id;
     const char* scope;
@@ -47,7 +48,7 @@ struct OrbisNpAuthGetIdTokenParameter {
 
 struct OrbisNpAuthGetIdTokenParameterA {
     u64 size;
-    s32 user_id;
+    Libraries::UserService::OrbisUserServiceUserId user_id;
     u8 padding[4];
     const OrbisNpClientId* client_id;
     const OrbisNpClientSecret* client_secret;
diff --git a/src/core/libraries/np/np_manager.h b/src/core/libraries/np/np_manager.h
index 61a283ba7..59864c173 100644
--- a/src/core/libraries/np/np_manager.h
+++ b/src/core/libraries/np/np_manager.h
@@ -23,8 +23,8 @@ enum class OrbisNpState : u32 {
     SignedIn = 2,
 };
 
-using OrbisNpStateCallbackForNpToolkit = PS4_SYSV_ABI void (*)(s32 userId, OrbisNpState state,
-                                                               void* userdata);
+using OrbisNpStateCallbackForNpToolkit = PS4_SYSV_ABI void (*)(
+    Libraries::UserService::OrbisUserServiceUserId userId, OrbisNpState state, void* userdata);
 
 enum class OrbisNpGamePresenseStatus {
     Offline = 0,
diff --git a/src/core/libraries/np/np_trophy.cpp b/src/core/libraries/np/np_trophy.cpp
index 7468de13b..976d614c0 100644
--- a/src/core/libraries/np/np_trophy.cpp
+++ b/src/core/libraries/np/np_trophy.cpp
@@ -149,7 +149,8 @@ int PS4_SYSV_ABI sceNpTrophyConfigHasGroupFeature() {
     return ORBIS_OK;
 }
 
-s32 PS4_SYSV_ABI sceNpTrophyCreateContext(OrbisNpTrophyContext* context, s32 user_id,
+s32 PS4_SYSV_ABI sceNpTrophyCreateContext(OrbisNpTrophyContext* context,
+                                          Libraries::UserService::OrbisUserServiceUserId user_id,
                                           uint32_t service_label, u64 options) {
     ASSERT(options == 0ull);
     if (!context) {
diff --git a/src/core/libraries/np/np_trophy.h b/src/core/libraries/np/np_trophy.h
index 36e59e537..ab187ae13 100644
--- a/src/core/libraries/np/np_trophy.h
+++ b/src/core/libraries/np/np_trophy.h
@@ -1,8 +1,9 @@
-// SPDX-FileCopyrightText: Copyright 2025 shadPS4 Emulator Project
+// SPDX-FileCopyrightText: Copyright 2025-2026 shadPS4 Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #pragma once
 
+#include <core/libraries/system/userservice.h>
 #include "common/types.h"
 #include "core/libraries/rtc/rtc.h"
 
@@ -132,7 +133,8 @@ int PS4_SYSV_ABI sceNpTrophyConfigGetTrophySetInfoInGroup();
 int PS4_SYSV_ABI sceNpTrophyConfigGetTrophySetVersion();
 int PS4_SYSV_ABI sceNpTrophyConfigGetTrophyTitleDetails();
 int PS4_SYSV_ABI sceNpTrophyConfigHasGroupFeature();
-s32 PS4_SYSV_ABI sceNpTrophyCreateContext(OrbisNpTrophyContext* context, s32 user_id,
+s32 PS4_SYSV_ABI sceNpTrophyCreateContext(OrbisNpTrophyContext* context,
+                                          Libraries::UserService::OrbisUserServiceUserId user_id,
                                           u32 service_label, u64 options);
 s32 PS4_SYSV_ABI sceNpTrophyCreateHandle(OrbisNpTrophyHandle* handle);
 int PS4_SYSV_ABI sceNpTrophyDestroyContext(OrbisNpTrophyContext context);
diff --git a/src/core/libraries/pad/pad.cpp b/src/core/libraries/pad/pad.cpp
index 09f404969..f433a87cc 100644
--- a/src/core/libraries/pad/pad.cpp
+++ b/src/core/libraries/pad/pad.cpp
@@ -159,7 +159,8 @@ int PS4_SYSV_ABI scePadGetFeatureReport() {
     return ORBIS_OK;
 }
 
-int PS4_SYSV_ABI scePadGetHandle(s32 userId, s32 type, s32 index) {
+int PS4_SYSV_ABI scePadGetHandle(Libraries::UserService::OrbisUserServiceUserId userId, s32 type,
+                                 s32 index) {
     if (!g_initialized) {
         return ORBIS_PAD_ERROR_NOT_INITIALIZED;
     }
@@ -256,7 +257,8 @@ int PS4_SYSV_ABI scePadMbusTerm() {
     return ORBIS_OK;
 }
 
-int PS4_SYSV_ABI scePadOpen(s32 userId, s32 type, s32 index, const OrbisPadOpenParam* pParam) {
+int PS4_SYSV_ABI scePadOpen(Libraries::UserService::OrbisUserServiceUserId userId, s32 type,
+                            s32 index, const OrbisPadOpenParam* pParam) {
     if (!g_initialized) {
         return ORBIS_PAD_ERROR_NOT_INITIALIZED;
     }
@@ -277,8 +279,8 @@ int PS4_SYSV_ABI scePadOpen(s32 userId, s32 type, s32 index, const OrbisPadOpenP
     return 1; // dummy
 }
 
-int PS4_SYSV_ABI scePadOpenExt(s32 userId, s32 type, s32 index,
-                               const OrbisPadOpenExtParam* pParam) {
+int PS4_SYSV_ABI scePadOpenExt(Libraries::UserService::OrbisUserServiceUserId userId, s32 type,
+                               s32 index, const OrbisPadOpenExtParam* pParam) {
     LOG_ERROR(Lib_Pad, "(STUBBED) called");
     if (Config::getUseSpecialPad()) {
         if (type != ORBIS_PAD_PORT_TYPE_SPECIAL)
diff --git a/src/core/libraries/pad/pad.h b/src/core/libraries/pad/pad.h
index ca6e8a73f..02ceaf3d9 100644
--- a/src/core/libraries/pad/pad.h
+++ b/src/core/libraries/pad/pad.h
@@ -1,8 +1,9 @@
-// SPDX-FileCopyrightText: Copyright 2024 shadPS4 Emulator Project
+// SPDX-FileCopyrightText: Copyright 2024-2026 shadPS4 Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #pragma once
 
+#include <core/libraries/system/userservice.h>
 #include "common/enum.h"
 #include "common/types.h"
 
@@ -276,7 +277,8 @@ int PS4_SYSV_ABI scePadGetExtControllerInformation(s32 handle,
                                                    OrbisPadExtendedControllerInformation* pInfo);
 int PS4_SYSV_ABI scePadGetExtensionUnitInfo();
 int PS4_SYSV_ABI scePadGetFeatureReport();
-int PS4_SYSV_ABI scePadGetHandle(s32 userId, s32 type, s32 index);
+int PS4_SYSV_ABI scePadGetHandle(Libraries::UserService::OrbisUserServiceUserId userId, s32 type,
+                                 s32 index);
 int PS4_SYSV_ABI scePadGetIdleCount();
 int PS4_SYSV_ABI scePadGetInfo();
 int PS4_SYSV_ABI scePadGetInfoByPortType();
@@ -294,8 +296,10 @@ int PS4_SYSV_ABI scePadIsMoveReproductionModel();
 int PS4_SYSV_ABI scePadIsValidHandle();
 int PS4_SYSV_ABI scePadMbusInit();
 int PS4_SYSV_ABI scePadMbusTerm();
-int PS4_SYSV_ABI scePadOpen(s32 userId, s32 type, s32 index, const OrbisPadOpenParam* pParam);
-int PS4_SYSV_ABI scePadOpenExt(s32 userId, s32 type, s32 index, const OrbisPadOpenExtParam* pParam);
+int PS4_SYSV_ABI scePadOpen(Libraries::UserService::OrbisUserServiceUserId userId, s32 type,
+                            s32 index, const OrbisPadOpenParam* pParam);
+int PS4_SYSV_ABI scePadOpenExt(Libraries::UserService::OrbisUserServiceUserId userId, s32 type,
+                               s32 index, const OrbisPadOpenExtParam* pParam);
 int PS4_SYSV_ABI scePadOpenExt2();
 int PS4_SYSV_ABI scePadOutputReport();
 int PS4_SYSV_ABI scePadRead(s32 handle, OrbisPadData* pData, s32 num);
diff --git a/src/core/libraries/remote_play/remoteplay.cpp b/src/core/libraries/remote_play/remoteplay.cpp
index 06d9fccfb..775450d26 100644
--- a/src/core/libraries/remote_play/remoteplay.cpp
+++ b/src/core/libraries/remote_play/remoteplay.cpp
@@ -54,7 +54,8 @@ int PS4_SYSV_ABI sceRemoteplayGetConnectHistory() {
     return ORBIS_OK;
 }
 
-int PS4_SYSV_ABI sceRemoteplayGetConnectionStatus(s32 userId, int* pStatus) {
+int PS4_SYSV_ABI sceRemoteplayGetConnectionStatus(
+    Libraries::UserService::OrbisUserServiceUserId userId, int* pStatus) {
     *pStatus = ORBIS_REMOTEPLAY_CONNECTION_STATUS_DISCONNECT;
     return ORBIS_OK;
 }
diff --git a/src/core/libraries/remote_play/remoteplay.h b/src/core/libraries/remote_play/remoteplay.h
index 35465d6df..b4614dca0 100644
--- a/src/core/libraries/remote_play/remoteplay.h
+++ b/src/core/libraries/remote_play/remoteplay.h
@@ -1,8 +1,9 @@
-// SPDX-FileCopyrightText: Copyright 2024 shadPS4 Emulator Project
+// SPDX-FileCopyrightText: Copyright 2024-2026 shadPS4 Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #pragma once
 
+#include <core/libraries/system/userservice.h>
 #include "common/types.h"
 
 namespace Core::Loader {
@@ -24,7 +25,8 @@ int PS4_SYSV_ABI sceRemoteplayDisconnect();
 int PS4_SYSV_ABI sceRemoteplayGeneratePinCode();
 int PS4_SYSV_ABI sceRemoteplayGetApMode();
 int PS4_SYSV_ABI sceRemoteplayGetConnectHistory();
-int PS4_SYSV_ABI sceRemoteplayGetConnectionStatus(s32 userId, int* pStatus);
+int PS4_SYSV_ABI sceRemoteplayGetConnectionStatus(
+    Libraries::UserService::OrbisUserServiceUserId userId, int* pStatus);
 int PS4_SYSV_ABI sceRemoteplayGetConnectUserId();
 int PS4_SYSV_ABI sceRemoteplayGetMbusDeviceInfo();
 int PS4_SYSV_ABI sceRemoteplayGetOperationStatus();
diff --git a/src/core/libraries/save_data/save_backup.cpp b/src/core/libraries/save_data/save_backup.cpp
index f85845f70..c5f66d883 100644
--- a/src/core/libraries/save_data/save_backup.cpp
+++ b/src/core/libraries/save_data/save_backup.cpp
@@ -167,7 +167,7 @@ void StopThread() {
     g_backup_thread_semaphore.release();
 }
 
-bool NewRequest(OrbisUserServiceUserId user_id, std::string_view title_id,
+bool NewRequest(Libraries::UserService::OrbisUserServiceUserId user_id, std::string_view title_id,
                 std::string_view dir_name, OrbisSaveDataEventType origin) {
     auto save_path = SaveInstance::MakeDirSavePath(user_id, title_id, dir_name);
 
diff --git a/src/core/libraries/save_data/save_backup.h b/src/core/libraries/save_data/save_backup.h
index 83a263c9b..2a5e54d49 100644
--- a/src/core/libraries/save_data/save_backup.h
+++ b/src/core/libraries/save_data/save_backup.h
@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: Copyright 2024 shadPS4 Emulator Project
+// SPDX-FileCopyrightText: Copyright 2024-2026 shadPS4 Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #pragma once
@@ -6,12 +6,11 @@
 #include <filesystem>
 #include <optional>
 
+#include <core/libraries/system/userservice.h>
 #include "common/types.h"
 
 namespace Libraries::SaveData {
 
-using OrbisUserServiceUserId = s32;
-
 namespace Backup {
 
 enum class WorkerStatus {
@@ -32,7 +31,7 @@ enum class OrbisSaveDataEventType : u32 {
 struct BackupRequest {
     bool done{};
 
-    OrbisUserServiceUserId user_id{};
+    Libraries::UserService::OrbisUserServiceUserId user_id{};
     std::string title_id{};
     std::string dir_name{};
     OrbisSaveDataEventType origin{};
@@ -45,7 +44,7 @@ void StartThread();
 
 void StopThread();
 
-bool NewRequest(OrbisUserServiceUserId user_id, std::string_view title_id,
+bool NewRequest(Libraries::UserService::OrbisUserServiceUserId user_id, std::string_view title_id,
                 std::string_view dir_name, OrbisSaveDataEventType origin);
 
 bool Restore(const std::filesystem::path& save_path);
diff --git a/src/core/libraries/save_data/save_instance.cpp b/src/core/libraries/save_data/save_instance.cpp
index 75a644fdb..bc6bbfd72 100644
--- a/src/core/libraries/save_data/save_instance.cpp
+++ b/src/core/libraries/save_data/save_instance.cpp
@@ -46,13 +46,13 @@ static const std::unordered_map<int, std::string> default_title = {
 
 namespace Libraries::SaveData {
 
-fs::path SaveInstance::MakeTitleSavePath(OrbisUserServiceUserId user_id,
+fs::path SaveInstance::MakeTitleSavePath(Libraries::UserService::OrbisUserServiceUserId user_id,
                                          std::string_view game_serial) {
     return Config::GetSaveDataPath() / std::to_string(user_id) / game_serial;
 }
 
-fs::path SaveInstance::MakeDirSavePath(OrbisUserServiceUserId user_id, std::string_view game_serial,
-                                       std::string_view dir_name) {
+fs::path SaveInstance::MakeDirSavePath(Libraries::UserService::OrbisUserServiceUserId user_id,
+                                       std::string_view game_serial, std::string_view dir_name) {
     return Config::GetSaveDataPath() / std::to_string(user_id) / game_serial / dir_name;
 }
 
@@ -89,8 +89,8 @@ void SaveInstance::SetupDefaultParamSFO(PSF& param_sfo, std::string dir_name,
 #undef P
 }
 
-SaveInstance::SaveInstance(int slot_num, OrbisUserServiceUserId user_id, std::string _game_serial,
-                           std::string_view _dir_name, int max_blocks)
+SaveInstance::SaveInstance(int slot_num, Libraries::UserService::OrbisUserServiceUserId user_id,
+                           std::string _game_serial, std::string_view _dir_name, int max_blocks)
     : slot_num(slot_num), user_id(user_id), game_serial(std::move(_game_serial)),
       dir_name(_dir_name),
       max_blocks(std::clamp(max_blocks, OrbisSaveDataBlocksMin2, OrbisSaveDataBlocksMax)) {
diff --git a/src/core/libraries/save_data/save_instance.h b/src/core/libraries/save_data/save_instance.h
index 6e7ac8f66..b758649b2 100644
--- a/src/core/libraries/save_data/save_instance.h
+++ b/src/core/libraries/save_data/save_instance.h
@@ -1,10 +1,11 @@
-// SPDX-FileCopyrightText: Copyright 2024 shadPS4 Emulator Project
+// SPDX-FileCopyrightText: Copyright 2024-2026 shadPS4 Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #pragma once
 
 #include <filesystem>
 
+#include <core/libraries/system/userservice.h>
 #include "common/io_file.h"
 #include "core/file_format/psf.h"
 
@@ -52,13 +53,13 @@ class SaveInstance {
 
 public:
     // Location of all save data for a title
-    static std::filesystem::path MakeTitleSavePath(OrbisUserServiceUserId user_id,
-                                                   std::string_view game_serial);
+    static std::filesystem::path MakeTitleSavePath(
+        Libraries::UserService::OrbisUserServiceUserId user_id, std::string_view game_serial);
 
     // Location of a specific save data directory
-    static std::filesystem::path MakeDirSavePath(OrbisUserServiceUserId user_id,
-                                                 std::string_view game_serial,
-                                                 std::string_view dir_name);
+    static std::filesystem::path MakeDirSavePath(
+        Libraries::UserService::OrbisUserServiceUserId user_id, std::string_view game_serial,
+        std::string_view dir_name);
 
     static uint64_t GetMaxBlockFromSFO(const PSF& psf);
 
@@ -67,8 +68,8 @@ public:
 
     static void SetupDefaultParamSFO(PSF& param_sfo, std::string dir_name, std::string game_serial);
 
-    explicit SaveInstance(int slot_num, OrbisUserServiceUserId user_id, std::string game_serial,
-                          std::string_view dir_name, int max_blocks = 0);
+    explicit SaveInstance(int slot_num, Libraries::UserService::OrbisUserServiceUserId user_id,
+                          std::string game_serial, std::string_view dir_name, int max_blocks = 0);
 
     ~SaveInstance();
 
diff --git a/src/core/libraries/save_data/save_memory.cpp b/src/core/libraries/save_data/save_memory.cpp
index 5f5ba8fea..0a16d4756 100644
--- a/src/core/libraries/save_data/save_memory.cpp
+++ b/src/core/libraries/save_data/save_memory.cpp
@@ -88,8 +88,8 @@ std::string GetSaveDir(u32 slot_id) {
     return dir;
 }
 
-std::filesystem::path GetSavePath(OrbisUserServiceUserId user_id, u32 slot_id,
-                                  std::string_view game_serial) {
+std::filesystem::path GetSavePath(Libraries::UserService::OrbisUserServiceUserId user_id,
+                                  u32 slot_id, std::string_view game_serial) {
     std::string dir(StandardDirnameSaveDataMemory);
     if (slot_id > 0) {
         dir += std::to_string(slot_id);
@@ -97,8 +97,8 @@ std::filesystem::path GetSavePath(OrbisUserServiceUserId user_id, u32 slot_id,
     return SaveInstance::MakeDirSavePath(user_id, game_serial, dir);
 }
 
-size_t SetupSaveMemory(OrbisUserServiceUserId user_id, u32 slot_id, std::string_view game_serial,
-                       size_t memory_size) {
+size_t SetupSaveMemory(Libraries::UserService::OrbisUserServiceUserId user_id, u32 slot_id,
+                       std::string_view game_serial, size_t memory_size) {
     std::lock_guard lck{g_slot_mtx};
 
     const auto save_dir = GetSavePath(user_id, slot_id, game_serial);
diff --git a/src/core/libraries/save_data/save_memory.h b/src/core/libraries/save_data/save_memory.h
index 7765b04cd..b524de8bc 100644
--- a/src/core/libraries/save_data/save_memory.h
+++ b/src/core/libraries/save_data/save_memory.h
@@ -4,26 +4,24 @@
 #pragma once
 
 #include <vector>
+#include <core/libraries/system/userservice.h>
 #include "core/libraries/save_data/save_backup.h"
 
 class PSF;
 
-namespace Libraries::SaveData {
-using OrbisUserServiceUserId = s32;
-} // namespace Libraries::SaveData
-
 namespace Libraries::SaveData::SaveMemory {
 
 void PersistMemory(u32 slot_id, bool lock = true);
 
 [[nodiscard]] std::string GetSaveDir(u32 slot_id);
 
-[[nodiscard]] std::filesystem::path GetSavePath(OrbisUserServiceUserId user_id, u32 slot_id,
-                                                std::string_view game_serial);
+[[nodiscard]] std::filesystem::path GetSavePath(
+    Libraries::UserService::OrbisUserServiceUserId user_id, u32 slot_id,
+    std::string_view game_serial);
 
 // returns the size of the save memory if exists
-size_t SetupSaveMemory(OrbisUserServiceUserId user_id, u32 slot_id, std::string_view game_serial,
-                       size_t memory_size);
+size_t SetupSaveMemory(Libraries::UserService::OrbisUserServiceUserId user_id, u32 slot_id,
+                       std::string_view game_serial, size_t memory_size);
 
 // Write the icon. Set buf to null to read the standard icon.
 void SetIcon(u32 slot_id, void* buf = nullptr, size_t buf_size = 0);
diff --git a/src/core/libraries/save_data/savedata.cpp b/src/core/libraries/save_data/savedata.cpp
index 7fba8ed21..a5199c297 100644
--- a/src/core/libraries/save_data/savedata.cpp
+++ b/src/core/libraries/save_data/savedata.cpp
@@ -42,7 +42,6 @@ enum class OrbisSaveDataSaveDataMemoryOption : u32 {
     UNLOCK_LIMITATIONS = 1 << 2,
 };
 
-using OrbisUserServiceUserId = s32;
 using OrbisSaveDataBlocks = u64;
 
 constexpr u32 OrbisSaveDataBlockSize = 32768; // 32 KiB
@@ -97,7 +96,7 @@ struct OrbisSaveDataFingerprint {
 };
 
 struct OrbisSaveDataBackup {
-    OrbisUserServiceUserId userId;
+    Libraries::UserService::OrbisUserServiceUserId userId;
     s32 : 32;
     const OrbisSaveDataTitleId* titleId;
     const OrbisSaveDataDirName* dirName;
@@ -106,7 +105,7 @@ struct OrbisSaveDataBackup {
 };
 
 struct OrbisSaveDataCheckBackupData {
-    OrbisUserServiceUserId userId;
+    Libraries::UserService::OrbisUserServiceUserId userId;
     s32 : 32;
     const OrbisSaveDataTitleId* titleId;
     const OrbisSaveDataDirName* dirName;
@@ -116,7 +115,7 @@ struct OrbisSaveDataCheckBackupData {
 };
 
 struct OrbisSaveDataDelete {
-    OrbisUserServiceUserId userId;
+    Libraries::UserService::OrbisUserServiceUserId userId;
     s32 : 32;
     const OrbisSaveDataTitleId* titleId;
     const OrbisSaveDataDirName* dirName;
@@ -153,7 +152,7 @@ struct OrbisSaveDataMemoryData {
 };
 
 struct OrbisSaveDataMemoryGet2 {
-    OrbisUserServiceUserId userId;
+    Libraries::UserService::OrbisUserServiceUserId userId;
     std::array<u8, 4> _pad;
     OrbisSaveDataMemoryData* data;
     OrbisSaveDataParam* param;
@@ -163,7 +162,7 @@ struct OrbisSaveDataMemoryGet2 {
 };
 
 struct OrbisSaveDataMemorySet2 {
-    OrbisUserServiceUserId userId;
+    Libraries::UserService::OrbisUserServiceUserId userId;
     std::array<u8, 4> _pad;
     const OrbisSaveDataMemoryData* data;
     const OrbisSaveDataParam* param;
@@ -175,7 +174,7 @@ struct OrbisSaveDataMemorySet2 {
 
 struct OrbisSaveDataMemorySetup2 {
     OrbisSaveDataSaveDataMemoryOption option;
-    OrbisUserServiceUserId userId;
+    Libraries::UserService::OrbisUserServiceUserId userId;
     size_t memorySize;
     size_t iconMemorySize;
     // +4.5
@@ -197,14 +196,14 @@ enum OrbisSaveDataMemorySyncOption : u32 {
 };
 
 struct OrbisSaveDataMemorySync {
-    OrbisUserServiceUserId userId;
+    Libraries::UserService::OrbisUserServiceUserId userId;
     u32 slotId;
     OrbisSaveDataMemorySyncOption option;
     std::array<u8, 28> _reserved;
 };
 
 struct OrbisSaveDataMount2 {
-    OrbisUserServiceUserId userId;
+    Libraries::UserService::OrbisUserServiceUserId userId;
     s32 : 32;
     const OrbisSaveDataDirName* dirName;
     OrbisSaveDataBlocks blocks;
@@ -214,7 +213,7 @@ struct OrbisSaveDataMount2 {
 };
 
 struct OrbisSaveDataMount {
-    OrbisUserServiceUserId userId;
+    Libraries::UserService::OrbisUserServiceUserId userId;
     s32 : 32;
     const OrbisSaveDataTitleId* titleId;
     const OrbisSaveDataDirName* dirName;
@@ -245,7 +244,7 @@ struct OrbisSaveDataMountResult {
 };
 
 struct OrbisSaveDataRestoreBackupData {
-    OrbisUserServiceUserId userId;
+    Libraries::UserService::OrbisUserServiceUserId userId;
     s32 : 32;
     const OrbisSaveDataTitleId* titleId;
     const OrbisSaveDataDirName* dirName;
@@ -256,7 +255,7 @@ struct OrbisSaveDataRestoreBackupData {
 };
 
 struct OrbisSaveDataTransferringMount {
-    OrbisUserServiceUserId userId;
+    Libraries::UserService::OrbisUserServiceUserId userId;
     const OrbisSaveDataTitleId* titleId;
     const OrbisSaveDataDirName* dirName;
     const OrbisSaveDataFingerprint* fingerprint;
@@ -264,7 +263,7 @@ struct OrbisSaveDataTransferringMount {
 };
 
 struct OrbisSaveDataDirNameSearchCond {
-    OrbisUserServiceUserId userId;
+    Libraries::UserService::OrbisUserServiceUserId userId;
     int : 32;
     const OrbisSaveDataTitleId* titleId;
     const OrbisSaveDataDirName* dirName;
@@ -303,7 +302,7 @@ using OrbisSaveDataEventType = Backup::OrbisSaveDataEventType;
 struct OrbisSaveDataEvent {
     OrbisSaveDataEventType type;
     s32 errorCode;
-    OrbisUserServiceUserId userId;
+    Libraries::UserService::OrbisUserServiceUserId userId;
     std::array<u8, 4> _pad;
     OrbisSaveDataTitleId titleId;
     OrbisSaveDataDirName dirName;
@@ -1106,8 +1105,9 @@ int PS4_SYSV_ABI sceSaveDataGetSaveDataCount() {
     return ORBIS_OK;
 }
 
-Error PS4_SYSV_ABI sceSaveDataGetSaveDataMemory(const OrbisUserServiceUserId userId, void* buf,
-                                                const size_t bufSize, const int64_t offset) {
+Error PS4_SYSV_ABI
+sceSaveDataGetSaveDataMemory(const Libraries::UserService::OrbisUserServiceUserId userId, void* buf,
+                             const size_t bufSize, const int64_t offset) {
     LOG_DEBUG(Lib_SaveData, "Redirecting to sceSaveDataGetSaveDataMemory2");
     OrbisSaveDataMemoryData data{};
     data.buf = buf;
@@ -1469,8 +1469,9 @@ int PS4_SYSV_ABI sceSaveDataSetSaveDataLibraryUser() {
     return ORBIS_OK;
 }
 
-Error PS4_SYSV_ABI sceSaveDataSetSaveDataMemory(OrbisUserServiceUserId userId, void* buf,
-                                                size_t bufSize, int64_t offset) {
+Error PS4_SYSV_ABI
+sceSaveDataSetSaveDataMemory(Libraries::UserService::OrbisUserServiceUserId userId, void* buf,
+                             size_t bufSize, int64_t offset) {
     LOG_DEBUG(Lib_SaveData, "Redirecting to sceSaveDataSetSaveDataMemory2");
     OrbisSaveDataMemoryData data{};
     data.buf = buf;
@@ -1527,8 +1528,9 @@ Error PS4_SYSV_ABI sceSaveDataSetSaveDataMemory2(const OrbisSaveDataMemorySet2*
     return Error::OK;
 }
 
-Error PS4_SYSV_ABI sceSaveDataSetupSaveDataMemory(OrbisUserServiceUserId userId, size_t memorySize,
-                                                  OrbisSaveDataParam* param) {
+Error PS4_SYSV_ABI
+sceSaveDataSetupSaveDataMemory(Libraries::UserService::OrbisUserServiceUserId userId,
+                               size_t memorySize, OrbisSaveDataParam* param) {
     LOG_DEBUG(Lib_SaveData, "called: userId = {}, memorySize = {}", userId, memorySize);
     OrbisSaveDataMemorySetup2 setupParam{};
     setupParam.userId = userId;
diff --git a/src/core/libraries/save_data/savedata.h b/src/core/libraries/save_data/savedata.h
index d1c625980..37a21dbc7 100644
--- a/src/core/libraries/save_data/savedata.h
+++ b/src/core/libraries/save_data/savedata.h
@@ -3,6 +3,7 @@
 
 #pragma once
 
+#include <core/libraries/system/userservice.h>
 #include "common/cstring.h"
 #include "common/types.h"
 
@@ -21,8 +22,6 @@ constexpr size_t OrbisSaveDataDetailMaxsize = 1024;  // Maximum detail name size
 enum class Error : u32;
 enum class OrbisSaveDataParamType : u32;
 
-using OrbisUserServiceUserId = s32;
-
 // Maximum size for a title ID (4 uppercase letters + 5 digits)
 constexpr int OrbisSaveDataTitleIdDataSize = 10;
 // Maximum save directory name size
@@ -126,8 +125,9 @@ Error PS4_SYSV_ABI sceSaveDataGetParam(const OrbisSaveDataMountPoint* mountPoint
                                        size_t paramBufSize, size_t* gotSize);
 Error PS4_SYSV_ABI sceSaveDataGetProgress(float* progress);
 int PS4_SYSV_ABI sceSaveDataGetSaveDataCount();
-Error PS4_SYSV_ABI sceSaveDataGetSaveDataMemory(OrbisUserServiceUserId userId, void* buf,
-                                                size_t bufSize, int64_t offset);
+Error PS4_SYSV_ABI
+sceSaveDataGetSaveDataMemory(Libraries::UserService::OrbisUserServiceUserId userId, void* buf,
+                             size_t bufSize, int64_t offset);
 Error PS4_SYSV_ABI sceSaveDataGetSaveDataMemory2(OrbisSaveDataMemoryGet2* getParam);
 int PS4_SYSV_ABI sceSaveDataGetSaveDataRootDir();
 int PS4_SYSV_ABI sceSaveDataGetSaveDataRootPath();
@@ -163,11 +163,13 @@ Error PS4_SYSV_ABI sceSaveDataSetParam(const OrbisSaveDataMountPoint* mountPoint
                                        OrbisSaveDataParamType paramType, const void* paramBuf,
                                        size_t paramBufSize);
 int PS4_SYSV_ABI sceSaveDataSetSaveDataLibraryUser();
-Error PS4_SYSV_ABI sceSaveDataSetSaveDataMemory(OrbisUserServiceUserId userId, void* buf,
-                                                size_t bufSize, int64_t offset);
+Error PS4_SYSV_ABI
+sceSaveDataSetSaveDataMemory(Libraries::UserService::OrbisUserServiceUserId userId, void* buf,
+                             size_t bufSize, int64_t offset);
 Error PS4_SYSV_ABI sceSaveDataSetSaveDataMemory2(const OrbisSaveDataMemorySet2* setParam);
-Error PS4_SYSV_ABI sceSaveDataSetupSaveDataMemory(OrbisUserServiceUserId userId, size_t memorySize,
-                                                  OrbisSaveDataParam* param);
+Error PS4_SYSV_ABI
+sceSaveDataSetupSaveDataMemory(Libraries::UserService::OrbisUserServiceUserId userId,
+                               size_t memorySize, OrbisSaveDataParam* param);
 Error PS4_SYSV_ABI sceSaveDataSetupSaveDataMemory2(const OrbisSaveDataMemorySetup2* setupParam,
                                                    OrbisSaveDataMemorySetupResult* result);
 int PS4_SYSV_ABI sceSaveDataShutdownStart();
diff --git a/src/core/libraries/share_play/shareplay.h b/src/core/libraries/share_play/shareplay.h
index ca65c9a9d..b67b01e93 100644
--- a/src/core/libraries/share_play/shareplay.h
+++ b/src/core/libraries/share_play/shareplay.h
@@ -1,8 +1,9 @@
-// SPDX-FileCopyrightText: Copyright 2024 shadPS4 Emulator Project
+// SPDX-FileCopyrightText: Copyright 2024-2026 shadPS4 Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #pragma once
 
+#include <core/libraries/system/userservice.h>
 #include "common/types.h"
 #include "core/libraries/np/np_types.h"
 
@@ -21,8 +22,8 @@ struct OrbisSharePlayConnectionInfo {
     int mode;
     Libraries::Np::OrbisNpOnlineId hostOnlineId;
     Libraries::Np::OrbisNpOnlineId visitorOnlineId;
-    s32 hostUserId;
-    s32 visitorUserId;
+    Libraries::UserService::OrbisUserServiceUserId hostUserId;
+    Libraries::UserService::OrbisUserServiceUserId visitorUserId;
 };
 
 int PS4_SYSV_ABI sceSharePlayCrashDaemon();
diff --git a/src/core/libraries/system/systemservice.h b/src/core/libraries/system/systemservice.h
index b8bdf0b5f..e3eeb21dc 100644
--- a/src/core/libraries/system/systemservice.h
+++ b/src/core/libraries/system/systemservice.h
@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: Copyright 2024 shadPS4 Emulator Project
+// SPDX-FileCopyrightText: Copyright 2024-2026 shadPS4 Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 // reference
 // https://github.com/OpenOrbis/OpenOrbis-PS4-Toolchain/blob/master/include/orbis/_types/sys_service.h
@@ -7,6 +7,7 @@
 #include <mutex>
 #include <queue>
 #include "common/types.h"
+#include "userservice.h"
 
 namespace Core::Loader {
 class SymbolsResolver;
@@ -119,12 +120,12 @@ struct OrbisSystemServiceEvent {
             char boot_argument[7169];
         } join_event;
         struct {
-            s32 user_id;
+            Libraries::UserService::OrbisUserServiceUserId userId;
             u32 np_service_label;
             u8 reserved[8184];
         } service_entitlement_update;
         struct {
-            s32 user_id;
+            Libraries::UserService::OrbisUserServiceUserId userId;
             u32 np_service_label;
             u8 reserved[8184];
         } unified_entitlement_update;
diff --git a/src/core/libraries/videoout/video_out.cpp b/src/core/libraries/videoout/video_out.cpp
index ece2640c9..e9176afdc 100644
--- a/src/core/libraries/videoout/video_out.cpp
+++ b/src/core/libraries/videoout/video_out.cpp
@@ -291,8 +291,8 @@ s32 PS4_SYSV_ABI sceVideoOutGetResolutionStatus(s32 handle, SceVideoOutResolutio
     return ORBIS_OK;
 }
 
-s32 PS4_SYSV_ABI sceVideoOutOpen(SceUserServiceUserId userId, s32 busType, s32 index,
-                                 const void* param) {
+s32 PS4_SYSV_ABI sceVideoOutOpen(Libraries::UserService::OrbisUserServiceUserId userId, s32 busType,
+                                 s32 index, const void* param) {
     LOG_INFO(Lib_VideoOut, "called");
     ASSERT(busType == SCE_VIDEO_OUT_BUS_TYPE_MAIN);
 
diff --git a/src/core/libraries/videoout/video_out.h b/src/core/libraries/videoout/video_out.h
index 7db09530b..ba2732ff7 100644
--- a/src/core/libraries/videoout/video_out.h
+++ b/src/core/libraries/videoout/video_out.h
@@ -1,8 +1,9 @@
-// SPDX-FileCopyrightText: Copyright 2024 shadPS4 Emulator Project
+// SPDX-FileCopyrightText: Copyright 2024-2026 shadPS4 Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #pragma once
 
+#include <core/libraries/system/userservice.h>
 #include "core/libraries/kernel/equeue.h"
 #include "core/libraries/videoout/buffer.h"
 
@@ -12,8 +13,6 @@ class SymbolsResolver;
 
 namespace Libraries::VideoOut {
 
-using SceUserServiceUserId = s32; // TODO move it to proper place
-
 // SceVideoOutBusType
 constexpr int SCE_VIDEO_OUT_BUS_TYPE_MAIN = 0;                    // Main output
 constexpr int SCE_VIDEO_OUT_BUS_TYPE_AUX_SOCIAL_SCREEN = 5;       // Aux output for social
@@ -131,8 +130,8 @@ s32 PS4_SYSV_ABI sceVideoOutWaitVblank(s32 handle);
 s32 PS4_SYSV_ABI sceVideoOutSubmitFlip(s32 handle, s32 bufferIndex, s32 flipMode, s64 flipArg);
 s32 PS4_SYSV_ABI sceVideoOutGetFlipStatus(s32 handle, FlipStatus* status);
 s32 PS4_SYSV_ABI sceVideoOutGetResolutionStatus(s32 handle, SceVideoOutResolutionStatus* status);
-s32 PS4_SYSV_ABI sceVideoOutOpen(SceUserServiceUserId userId, s32 busType, s32 index,
-                                 const void* param);
+s32 PS4_SYSV_ABI sceVideoOutOpen(Libraries::UserService::OrbisUserServiceUserId userId, s32 busType,
+                                 s32 index, const void* param);
 s32 PS4_SYSV_ABI sceVideoOutClose(s32 handle);
 s32 PS4_SYSV_ABI sceVideoOutGetEventId(const Kernel::SceKernelEvent* ev);
 s32 PS4_SYSV_ABI sceVideoOutGetEventData(const Kernel::SceKernelEvent* ev, s64* data);