diff --git a/data/sql/updates/pending_db_characters/rev_decouple_item_guids.sql b/data/sql/updates/pending_db_characters/rev_decouple_item_guids.sql
new file mode 100644
index 0000000000..4ddf946f42
--- /dev/null
+++ b/data/sql/updates/pending_db_characters/rev_decouple_item_guids.sql
@@ -0,0 +1,40 @@
+-- Decouple item GUIDs: widen to BIGINT UNSIGNED for persistent DB IDs
+-- Item instance primary key to BIGINT
+ALTER TABLE `item_instance`
+  MODIFY COLUMN `guid` BIGINT UNSIGNED NOT NULL,
+  DROP PRIMARY KEY,
+  ADD PRIMARY KEY (`guid`);
+
+-- Character inventory references
+ALTER TABLE `character_inventory`
+  MODIFY COLUMN `item` BIGINT UNSIGNED NOT NULL;
+
+-- Mail items references
+ALTER TABLE `mail_items`
+  MODIFY COLUMN `item_guid` BIGINT UNSIGNED NOT NULL;
+
+-- Auctionhouse references
+ALTER TABLE `auctionhouse`
+  MODIFY COLUMN `itemguid` BIGINT UNSIGNED NOT NULL,
+  DROP INDEX `item_guid`,
+  ADD UNIQUE KEY `item_guid` (`itemguid`);
+
+-- Guild bank references
+ALTER TABLE `guild_bank_item`
+  MODIFY COLUMN `item_guid` BIGINT UNSIGNED NOT NULL,
+  DROP INDEX `Idx_item_guid`,
+  ADD KEY `Idx_item_guid` (`item_guid`);
+
+-- Refund/trade/gift tables referencing items by guid
+ALTER TABLE `item_refund_instance`
+  MODIFY COLUMN `item_guid` BIGINT UNSIGNED NOT NULL;
+
+ALTER TABLE `item_soulbound_trade_data`
+  MODIFY COLUMN `itemGuid` BIGINT UNSIGNED NOT NULL,
+  DROP PRIMARY KEY,
+  ADD PRIMARY KEY (`itemGuid`);
+
+ALTER TABLE `character_gifts`
+  MODIFY COLUMN `item_guid` BIGINT UNSIGNED NOT NULL,
+  DROP PRIMARY KEY,
+  ADD PRIMARY KEY (`item_guid`);
diff --git a/src/server/game/AuctionHouse/AuctionHouseMgr.cpp b/src/server/game/AuctionHouse/AuctionHouseMgr.cpp
index dcc1b76621..c6534f81ee 100644
--- a/src/server/game/AuctionHouse/AuctionHouseMgr.cpp
+++ b/src/server/game/AuctionHouse/AuctionHouseMgr.cpp
@@ -29,6 +29,7 @@
 #include "UpdateTime.h"
 #include "World.h"
 #include "WorldPacket.h"
+#include "Entities/Item/ItemGuidMap.h"
 #include <vector>
 
 constexpr auto AH_MINIMUM_DEPOSIT = 100;
@@ -580,7 +581,11 @@ void AuctionEntry::SaveToDB(CharacterDatabaseTransaction trans) const
     CharacterDatabasePreparedStatement* stmt = CharacterDatabase.GetPreparedStatement(CHAR_INS_AUCTION);
     stmt->SetData(0, Id);
     stmt->SetData(1, houseId);
-    stmt->SetData(2, item_guid.GetCounter());
+    {
+        Item* it = sAuctionMgr->GetAItem(item_guid);
+        uint64 dbGuid = it ? it->GetDbGuid() : static_cast<uint64>(item_guid.GetCounter());
+        stmt->SetData(2, dbGuid);
+    }
     stmt->SetData(3, owner.GetCounter());
     stmt->SetData (4, buyout);
     stmt->SetData(5, uint32(expire_time));
@@ -595,7 +600,11 @@ bool AuctionEntry::LoadFromDB(Field* fields)
 {
     Id = fields[0].Get<uint32>();
     houseId = AuctionHouseId(fields[1].Get<uint8>());
-    item_guid = ObjectGuid::Create<HighGuid::Item>(fields[2].Get<uint32>());
+    {
+        uint64 dbGuid = fields[2].Get<uint64>();
+        uint32 low = sItemGuidMap->Acquire(dbGuid);
+        item_guid = ObjectGuid::Create<HighGuid::Item>(low);
+    }
     item_template = fields[3].Get<uint32>();
     itemCount = fields[4].Get<uint32>();
     owner = ObjectGuid::Create<HighGuid::Player>(fields[5].Get<uint32>());
diff --git a/src/server/game/Entities/Item/Item.cpp b/src/server/game/Entities/Item/Item.cpp
index 36c45e5449..961002c520 100644
--- a/src/server/game/Entities/Item/Item.cpp
+++ b/src/server/game/Entities/Item/Item.cpp
@@ -28,6 +28,7 @@
 #include "StringConvert.h"
 #include "Tokenize.h"
 #include "WorldPacket.h"
+#include "ItemGuidMap.h"
 
 void AddItemsSetItem(Player* player, Item* item)
 {
@@ -374,7 +375,12 @@ void Item::SaveToDB(CharacterDatabaseTransaction trans)
                 stmt->SetData(++index, GetUInt32Value(ITEM_FIELD_DURABILITY));
                 stmt->SetData(++index, GetUInt32Value(ITEM_FIELD_CREATE_PLAYED_TIME));
                 stmt->SetData(++index, m_text);
-                stmt->SetData(++index, guid);
+                if (m_dbGuid == 0)
+                {
+                    m_dbGuid = sItemGuidMap->AcquireDbGuid();
+                    sItemGuidMap->Bind(m_dbGuid, guid);
+                }
+                stmt->SetData(++index, static_cast<uint64>(m_dbGuid));
 
                 trans->Append(stmt);
 
@@ -382,7 +388,7 @@ void Item::SaveToDB(CharacterDatabaseTransaction trans)
                 {
                     stmt = CharacterDatabase.GetPreparedStatement(CHAR_UPD_GIFT_OWNER);
                     stmt->SetData(0, GetOwnerGUID().GetCounter());
-                    stmt->SetData(1, guid);
+                    stmt->SetData(1, static_cast<uint64>(m_dbGuid));
                     trans->Append(stmt);
                 }
                 break;
@@ -390,19 +396,21 @@ void Item::SaveToDB(CharacterDatabaseTransaction trans)
         case ITEM_REMOVED:
             {
                 CharacterDatabasePreparedStatement* stmt = CharacterDatabase.GetPreparedStatement(CHAR_DEL_ITEM_INSTANCE);
-                stmt->SetData(0, guid);
+                stmt->SetData(0, static_cast<uint64>(m_dbGuid));
                 trans->Append(stmt);
 
                 if (IsWrapped())
                 {
                     stmt = CharacterDatabase.GetPreparedStatement(CHAR_DEL_GIFT);
-                    stmt->SetData(0, guid);
+                    stmt->SetData(0, static_cast<uint64>(m_dbGuid));
                     trans->Append(stmt);
                 }
 
                 if (!isInTransaction)
                     CharacterDatabase.CommitTransaction(trans);
 
+                if (m_dbGuid)
+                    sItemGuidMap->Release(m_dbGuid);
                 delete this;
                 return;
             }
@@ -514,12 +522,105 @@ bool Item::LoadFromDB(ObjectGuid::LowType guid, ObjectGuid owner_guid, Field* fi
     return true;
 }
 
+bool Item::LoadFromDB64(uint64 dbGuid, ObjectGuid owner_guid, Field* fields, uint32 entry)
+{
+    uint32 low = sItemGuidMap->Acquire(dbGuid);
+    Object::_Create(low, 0, HighGuid::Item);
+    m_dbGuid = dbGuid;
+
+    SetEntry(entry);
+    SetObjectScale(1.0f);
+
+    ItemTemplate const* proto = GetTemplate();
+    if (!proto)
+    {
+        LOG_ERROR("entities.item", "Invalid entry {} for item {}. Refusing to load.", GetEntry(), GetGUID().ToString());
+        return false;
+    }
+
+    if (owner_guid)
+        SetOwnerGUID(owner_guid);
+
+    bool need_save = false;
+    SetGuidValue(ITEM_FIELD_CREATOR,      ObjectGuid::Create<HighGuid::Player>(fields[0].Get<uint32>()));
+    SetGuidValue(ITEM_FIELD_GIFTCREATOR,  ObjectGuid::Create<HighGuid::Player>(fields[1].Get<uint32>()));
+    SetCount(                            fields[2].Get<uint32>());
+
+    // Duration
+    uint32 duration = fields[3].Get<uint32>();
+    SetUInt32Value(ITEM_FIELD_DURATION, duration);
+    if ((proto->Duration == 0) != (duration == 0))
+    {
+        SetUInt32Value(ITEM_FIELD_DURATION, proto->Duration);
+        need_save = true;
+    }
+
+    // Charges
+    {
+        std::vector<std::string_view> tokens = Acore::Tokenize(fields[4].Get<std::string_view>(), ' ', false);
+        if (tokens.size() == MAX_ITEM_PROTO_SPELLS)
+        {
+            for (uint8 i = 0; i < MAX_ITEM_PROTO_SPELLS; ++i)
+            {
+                if (Optional<int32> charges = Acore::StringTo<int32>(tokens[i]))
+                    SetSpellCharges(i, *charges);
+                else
+                    LOG_ERROR("entities.item", "Invalid charge info '{}' for item {}, charge data not loaded.", tokens.at(i), GetGUID().ToString());
+            }
+        }
+    }
+
+    // Flags
+    SetUInt32Value(ITEM_FIELD_FLAGS, fields[5].Get<uint32>());
+    if (IsSoulBound() && proto->Bonding == NO_BIND && sScriptMgr->CanApplySoulboundFlag(this, proto))
+    {
+        ApplyModFlag(ITEM_FIELD_FLAGS, ITEM_FIELD_FLAG_SOULBOUND, false);
+        need_save = true;
+    }
+
+    // Enchantments
+    if (!_LoadIntoDataField(fields[6].Get<std::string>(), ITEM_FIELD_ENCHANTMENT_1_1, MAX_ENCHANTMENT_SLOT * MAX_ENCHANTMENT_OFFSET))
+    {
+        LOG_WARN("entities.item", "Invalid enchantment data '{}' for item {}. Forcing partial load.", fields[6].Get<std::string>(), GetGUID().ToString());
+    }
+
+    // Random properties
+    SetInt32Value(ITEM_FIELD_RANDOM_PROPERTIES_ID, fields[7].Get<int16>());
+    if (GetItemRandomPropertyId() < 0)
+        UpdateItemSuffixFactor();
+
+    // Durability
+    uint32 durability = fields[8].Get<uint16>();
+    SetUInt32Value(ITEM_FIELD_DURABILITY, durability);
+    SetUInt32Value(ITEM_FIELD_MAXDURABILITY, proto->MaxDurability);
+    if (durability > proto->MaxDurability && !IsWrapped())
+    {
+        SetUInt32Value(ITEM_FIELD_DURABILITY, proto->MaxDurability);
+        need_save = true;
+    }
+
+    SetUInt32Value(ITEM_FIELD_CREATE_PLAYED_TIME, fields[9].Get<uint32>());
+    SetText(fields[10].Get<std::string>());
+
+    if (need_save)
+    {
+        CharacterDatabasePreparedStatement* stmt = CharacterDatabase.GetPreparedStatement(CHAR_UPD_ITEM_INSTANCE_ON_LOAD);
+        stmt->SetData(0, GetUInt32Value(ITEM_FIELD_DURATION));
+        stmt->SetData(1, GetUInt32Value(ITEM_FIELD_FLAGS));
+        stmt->SetData(2, GetUInt32Value(ITEM_FIELD_DURABILITY));
+        stmt->SetData(3, static_cast<uint64>(m_dbGuid));
+        CharacterDatabase.Execute(stmt);
+    }
+
+    return true;
+}
+
 /*static*/
 void Item::DeleteFromDB(CharacterDatabaseTransaction trans, ObjectGuid::LowType itemGuid)
 {
     sScriptMgr->OnGlobalItemDelFromDB(trans, itemGuid);
     CharacterDatabasePreparedStatement* stmt = CharacterDatabase.GetPreparedStatement(CHAR_DEL_ITEM_INSTANCE);
-    stmt->SetData(0, itemGuid);
+    stmt->SetData(0, static_cast<uint64>(itemGuid));
     trans->Append(stmt);
 }
 
@@ -532,7 +633,7 @@ void Item::DeleteFromDB(CharacterDatabaseTransaction trans)
 void Item::DeleteFromInventoryDB(CharacterDatabaseTransaction trans, ObjectGuid::LowType itemGuid)
 {
     CharacterDatabasePreparedStatement* stmt = CharacterDatabase.GetPreparedStatement(CHAR_DEL_CHAR_INVENTORY_BY_ITEM);
-    stmt->SetData(0, itemGuid);
+    stmt->SetData(0, static_cast<uint64>(itemGuid));
     trans->Append(stmt);
 }
 
@@ -1098,8 +1199,9 @@ Item* Item::CreateItem(uint32 item, uint32 count, Player const* player, bool clo
         ASSERT_NODEBUGINFO(count != 0 && "pProto->Stackable == 0 but checked at loading already");
 
         Item* pItem = NewItemOrBag(pProto);
-        if (pItem->Create(sObjectMgr->GetGenerator<HighGuid::Item>().Generate(), item, player))
-        {
+        uint32 newLow = sItemGuidMap->AcquireForNew();
+        if (pItem->Create(newLow, item, player))
+            {
             pItem->SetCount(count);
             if (!clone)
                 pItem->SetItemRandomProperties(randomPropertyId ? randomPropertyId : Item::GenerateItemRandomPropertyId(item));
@@ -1174,11 +1276,11 @@ void Item::SaveRefundDataToDB()
     CharacterDatabaseTransaction trans = CharacterDatabase.BeginTransaction();
 
     CharacterDatabasePreparedStatement* stmt = CharacterDatabase.GetPreparedStatement(CHAR_DEL_ITEM_REFUND_INSTANCE);
-    stmt->SetData(0, GetGUID().GetCounter());
+    stmt->SetData(0, static_cast<uint64>(GetDbGuid()));
     trans->Append(stmt);
 
     stmt = CharacterDatabase.GetPreparedStatement(CHAR_INS_ITEM_REFUND_INSTANCE);
-    stmt->SetData(0, GetGUID().GetCounter());
+    stmt->SetData(0, static_cast<uint64>(GetDbGuid()));
     stmt->SetData(1, GetRefundRecipient());
     stmt->SetData(2, GetPaidMoney());
     stmt->SetData(3, uint16(GetPaidExtendedCost()));
@@ -1192,7 +1294,7 @@ void Item::DeleteRefundDataFromDB(CharacterDatabaseTransaction* trans)
     if (trans)
     {
         CharacterDatabasePreparedStatement* stmt = CharacterDatabase.GetPreparedStatement(CHAR_DEL_ITEM_REFUND_INSTANCE);
-        stmt->SetData(0, GetGUID().GetCounter());
+        stmt->SetData(0, static_cast<uint64>(GetDbGuid()));
         (*trans)->Append(stmt);
     }
 }
@@ -1270,7 +1372,7 @@ void Item::ClearSoulboundTradeable(Player* currentOwner)
     allowedGUIDs.clear();
     SetState(ITEM_CHANGED, currentOwner);
     CharacterDatabasePreparedStatement* stmt = CharacterDatabase.GetPreparedStatement(CHAR_DEL_ITEM_BOP_TRADE);
-    stmt->SetData(0, GetGUID().GetCounter());
+    stmt->SetData(0, static_cast<uint64>(GetDbGuid()));
     CharacterDatabase.Execute(stmt);
 }
 
diff --git a/src/server/game/Entities/Item/Item.h b/src/server/game/Entities/Item/Item.h
index a4ce99fdd0..a4ffdefe08 100644
--- a/src/server/game/Entities/Item/Item.h
+++ b/src/server/game/Entities/Item/Item.h
@@ -239,11 +239,18 @@ public:
     [[nodiscard]] bool IsBoundByEnchant() const;
     [[nodiscard]] bool IsBoundByTempEnchant() const;
     virtual void SaveToDB(CharacterDatabaseTransaction trans);
+    // Legacy: Load by low-guid (pre-decoupling)
     virtual bool LoadFromDB(ObjectGuid::LowType guid, ObjectGuid owner_guid, Field* fields, uint32 entry);
+    // Decoupled: Load by persistent db-guid (64-bit), will map to a transient low-guid
+    virtual bool LoadFromDB64(uint64 dbGuid, ObjectGuid owner_guid, Field* fields, uint32 entry);
     static void DeleteFromDB(CharacterDatabaseTransaction trans, ObjectGuid::LowType itemGuid);
     virtual void DeleteFromDB(CharacterDatabaseTransaction trans);
     static void DeleteFromInventoryDB(CharacterDatabaseTransaction trans, ObjectGuid::LowType itemGuid);
     void DeleteFromInventoryDB(CharacterDatabaseTransaction trans);
+
+    // Decoupled: DB GUID accessors
+    uint64 GetDbGuid() const { return m_dbGuid; }
+    void SetDbGuid(uint64 v) { m_dbGuid = v; }
     void SaveRefundDataToDB();
     void DeleteRefundDataFromDB(CharacterDatabaseTransaction* trans);
 
@@ -376,5 +383,6 @@ private:
     uint32 m_paidMoney;
     uint32 m_paidExtendedCost;
     AllowedLooterSet allowedGUIDs;
+    uint64 m_dbGuid = 0;                                // Persistent DB identifier (64-bit)
 };
 #endif
diff --git a/src/server/game/Entities/Item/ItemGuidMap.cpp b/src/server/game/Entities/Item/ItemGuidMap.cpp
new file mode 100644
index 0000000000..2230e50198
--- /dev/null
+++ b/src/server/game/Entities/Item/ItemGuidMap.cpp
@@ -0,0 +1,59 @@
+/*
+ * Lightweight runtime mapper for Items: DB GUID (uint64) <-> transient Low GUID (uint32)
+ */
+
+#include "ItemGuidMap.h"
+
+ItemGuidMap* ItemGuidMap::instance()
+{
+    // Function-local static to respect the private constructor
+    static ItemGuidMap s_Instance;
+    return &s_Instance;
+}
+
+uint32_t ItemGuidMap::NextLow()
+{
+    // Simple monotonically increasing counter with free-list reuse
+    if (!_free.empty())
+    {
+        uint32_t id = _free.front();
+        _free.pop();
+        return id;
+    }
+    // wrap-around protection is not handled here; upper layers should ensure recyclable usage
+    return _next++;
+}
+
+uint32_t ItemGuidMap::Acquire(uint64_t dbGuid)
+{
+    std::lock_guard<std::mutex> g(_mtx);
+    auto it = _dbToLow.find(dbGuid);
+    if (it != _dbToLow.end())
+        return it->second;
+    uint32_t low = NextLow();
+    _dbToLow.emplace(dbGuid, low);
+    return low;
+}
+
+uint32_t ItemGuidMap::AcquireForNew()
+{
+    std::lock_guard<std::mutex> g(_mtx);
+    return NextLow();
+}
+
+void ItemGuidMap::Bind(uint64_t dbGuid, uint32_t lowGuid)
+{
+    std::lock_guard<std::mutex> g(_mtx);
+    _dbToLow[dbGuid] = lowGuid;
+}
+
+void ItemGuidMap::Release(uint64_t dbGuid)
+{
+    std::lock_guard<std::mutex> g(_mtx);
+    auto it = _dbToLow.find(dbGuid);
+    if (it != _dbToLow.end())
+    {
+        _free.push(it->second);
+        _dbToLow.erase(it);
+    }
+}
diff --git a/src/server/game/Entities/Item/ItemGuidMap.h b/src/server/game/Entities/Item/ItemGuidMap.h
new file mode 100644
index 0000000000..1929c74519
--- /dev/null
+++ b/src/server/game/Entities/Item/ItemGuidMap.h
@@ -0,0 +1,56 @@
+/*
+ * Lightweight runtime mapper for Items: DB GUID (uint64) <-> transient Low GUID (uint32)
+ */
+
+#pragma once
+
+#include <cstdint>
+#include <unordered_map>
+#include <queue>
+#include <mutex>
+#include <atomic>
+
+class ItemGuidMap
+{
+public:
+    static ItemGuidMap* instance();
+
+    // Acquire or create a low-guid for a persistent db-guid
+    uint32_t Acquire(uint64_t dbGuid);
+
+    // Reserve a new low-guid for a brand new, unsaved item (dbGuid not known yet)
+    uint32_t AcquireForNew();
+
+    // Bind a db-guid to an already reserved low-guid (used after first save assigns dbGuid)
+    void Bind(uint64_t dbGuid, uint32_t lowGuid);
+
+    // Release mapping and recycle low-guid
+    void Release(uint64_t dbGuid);
+
+    // Initialize the starting value for persistent DB GUID generator
+    void InitDbGuidSeed(uint64_t start)
+    {
+        std::lock_guard<std::mutex> g(_mtx);
+        if (_nextDbGuid.load() == 0 || start > _nextDbGuid.load())
+            _nextDbGuid.store(start);
+    }
+
+    // Get next persistent DB GUID
+    uint64_t AcquireDbGuid()
+    {
+        return _nextDbGuid.fetch_add(1, std::memory_order_relaxed);
+    }
+
+private:
+    ItemGuidMap() = default;
+
+    uint32_t NextLow();
+
+    std::unordered_map<uint64_t, uint32_t> _dbToLow;
+    std::queue<uint32_t> _free;
+    uint32_t _next{1};
+    std::mutex _mtx;
+    std::atomic<uint64_t> _nextDbGuid{0};
+};
+
+#define sItemGuidMap ItemGuidMap::instance()
diff --git a/src/server/game/Entities/Player/PlayerStorage.cpp b/src/server/game/Entities/Player/PlayerStorage.cpp
index 80f6a068e4..d12a238708 100644
--- a/src/server/game/Entities/Player/PlayerStorage.cpp
+++ b/src/server/game/Entities/Player/PlayerStorage.cpp
@@ -64,6 +64,7 @@
 #include "Util.h"
 #include "World.h"
 #include "WorldPacket.h"
+#include "Entities/Item/ItemGuidMap.h"
 
 /// @todo: this import is not necessary for compilation and marked as unused by the IDE
 //  however, for some reasons removing it would cause a damn linking issue
@@ -2567,7 +2568,7 @@ Item* Player::StoreNewItem(ItemPosCountVec const& dest, uint32 item, bool update
                 ss << ' ' << (*itr).GetCounter();
 
             CharacterDatabasePreparedStatement* stmt = CharacterDatabase.GetPreparedStatement(CHAR_INS_ITEM_BOP_TRADE);
-            stmt->SetData(0, pItem->GetGUID().GetCounter());
+            stmt->SetData(0, static_cast<uint64>(pItem->GetDbGuid()));
             stmt->SetData(1, ss.str());
             CharacterDatabase.Execute(stmt);
         }
@@ -3036,7 +3037,7 @@ void Player::DestroyItem(uint8 bag, uint8 slot, bool update)
         if (pItem->IsWrapped())
         {
             CharacterDatabasePreparedStatement* stmt = CharacterDatabase.GetPreparedStatement(CHAR_DEL_GIFT);
-            stmt->SetData(0, pItem->GetGUID().GetCounter());
+            stmt->SetData(0, static_cast<uint64>(pItem->GetDbGuid()));
             CharacterDatabase.Execute(stmt);
         }
 
@@ -5973,20 +5974,21 @@ void Player::_LoadInventory(PreparedQueryResult result, uint32 timeDiff)
 Item* Player::_LoadItem(CharacterDatabaseTransaction trans, uint32 zoneId, uint32 timeDiff, Field* fields)
 {
     Item* item = nullptr;
-    ObjectGuid::LowType itemGuid  = fields[13].Get<uint32>();
+    uint64 itemGuidDb  = fields[13].Get<uint64>();
     uint32 itemEntry = fields[14].Get<uint32>();
     if (ItemTemplate const* proto = sObjectMgr->GetItemTemplate(itemEntry))
     {
         bool remove = false;
         item = NewItemOrBag(proto);
-        if (item->LoadFromDB(itemGuid, GetGUID(), fields, itemEntry))
+        bool ok = item->LoadFromDB64(itemGuidDb, GetGUID(), fields, itemEntry);
+        if (ok)
         {
             CharacterDatabasePreparedStatement* stmt = nullptr;
 
             // Do not allow to have item limited to another map/zone in alive state
             if (IsAlive() && item->IsLimitedToAnotherMapOrZone(GetMapId(), zoneId))
             {
-                LOG_DEBUG("entities.player.loading", "Player::_LoadInventory: player ({}, name: '{}', map: {}) has item ({}, entry: {}) limited to another map ({}). Deleting item.",
+                        LOG_DEBUG("entities.player.loading", "Player::_LoadInventory: player ({}, name: '{}', map: {}) has item ({}, entry: {}) limited to another map ({}). Deleting item.",
                           GetGUID().ToString(), GetName(), GetMapId(), item->GetGUID().ToString(), item->GetEntry(), zoneId);
                 remove = true;
             }
@@ -6004,7 +6006,7 @@ Item* Player::_LoadItem(CharacterDatabaseTransaction trans, uint32 zoneId, uint3
                     LOG_DEBUG("entities.player.loading", "Player::_LoadInventory: player ({}, name: '{}') has item ({}, entry: {}) with expired refund time ({}). Deleting refund data and removing refundable flag.",
                               GetGUID().ToString(), GetName(), item->GetGUID().ToString(), item->GetEntry(), item->GetPlayedTime());
                     stmt = CharacterDatabase.GetPreparedStatement(CHAR_DEL_ITEM_REFUND_INSTANCE);
-                    stmt->SetData(0, item->GetGUID().GetCounter());
+                    stmt->SetData(0, static_cast<uint64>(item->GetDbGuid()));
                     trans->Append(stmt);
 
                     item->RemoveFlag(ITEM_FIELD_FLAGS, ITEM_FIELD_FLAG_REFUNDABLE);
@@ -6013,7 +6015,7 @@ Item* Player::_LoadItem(CharacterDatabaseTransaction trans, uint32 zoneId, uint3
                 {
                     // xinef: sync query
                     stmt = CharacterDatabase.GetPreparedStatement(CHAR_SEL_ITEM_REFUNDS);
-                    stmt->SetData(0, item->GetGUID().GetCounter());
+                    stmt->SetData(0, static_cast<uint64>(item->GetDbGuid()));
                     stmt->SetData(1, GetGUID().GetCounter());
                     if (PreparedQueryResult result = CharacterDatabase.Query(stmt))
                     {
@@ -6033,7 +6035,7 @@ Item* Player::_LoadItem(CharacterDatabaseTransaction trans, uint32 zoneId, uint3
             else if (item->IsBOPTradable())
             {
                 stmt = CharacterDatabase.GetPreparedStatement(CHAR_SEL_ITEM_BOP_TRADE);
-                stmt->SetData(0, item->GetGUID().GetCounter());
+                stmt->SetData(0, static_cast<uint64>(item->GetDbGuid()));
 
                 if (PreparedQueryResult result = CharacterDatabase.Query(stmt))
                 {
@@ -6083,13 +6085,15 @@ Item* Player::_LoadItem(CharacterDatabaseTransaction trans, uint32 zoneId, uint3
         else
         {
             LOG_ERROR("entities.player", "Player::_LoadInventory: player ({}, name: '{}') has broken item (GUID: {}, entry: {}) in inventory. Deleting item.",
-                      GetGUID().ToString(), GetName(), itemGuid, itemEntry);
+                      GetGUID().ToString(), GetName(), itemGuidDb, itemEntry);
             remove = true;
         }
         // Remove item from inventory if necessary
         if (remove)
         {
-            Item::DeleteFromInventoryDB(trans, itemGuid);
+            CharacterDatabasePreparedStatement* delStmt = CharacterDatabase.GetPreparedStatement(CHAR_DEL_CHAR_INVENTORY_BY_ITEM);
+            delStmt->SetData(0, static_cast<uint64>(item->GetDbGuid()));
+            trans->Append(delStmt);
             item->FSetState(ITEM_REMOVED);
             item->SaveToDB(trans);                           // it also deletes item object!
             item = nullptr;
@@ -6099,8 +6103,12 @@ Item* Player::_LoadItem(CharacterDatabaseTransaction trans, uint32 zoneId, uint3
     {
         LOG_ERROR("entities.player", "Player::_LoadInventory: player ({}, name: '{}') has unknown item (entry: {}) in inventory. Deleting item.",
                   GetGUID().ToString(), GetName(), itemEntry);
-        Item::DeleteFromInventoryDB(trans, itemGuid);
-        Item::DeleteFromDB(trans, itemGuid);
+        CharacterDatabasePreparedStatement* stmt = CharacterDatabase.GetPreparedStatement(CHAR_DEL_CHAR_INVENTORY_BY_ITEM);
+        stmt->SetData(0, static_cast<uint64>(itemGuidDb));
+        trans->Append(stmt);
+        stmt = CharacterDatabase.GetPreparedStatement(CHAR_DEL_ITEM_INSTANCE);
+        stmt->SetData(0, static_cast<uint64>(itemGuidDb));
+        trans->Append(stmt);
     }
     return item;
 }
@@ -6108,19 +6116,19 @@ Item* Player::_LoadItem(CharacterDatabaseTransaction trans, uint32 zoneId, uint3
 // load mailed item which should receive current player
 Item* Player::_LoadMailedItem(ObjectGuid const& playerGuid, Player* player, uint32 mailId, Mail* mail, Field* fields)
 {
-    ObjectGuid::LowType itemGuid = fields[11].Get<uint32>();
+    uint64 itemGuidDb = fields[11].Get<uint64>();
     uint32 itemEntry = fields[12].Get<uint32>();
 
     ItemTemplate const* proto = sObjectMgr->GetItemTemplate(itemEntry);
     if (!proto)
     {
         LOG_ERROR("entities.player", "Player {} ({}) has unknown item in mailed items (GUID: {}, Entry: {}) in mail ({}), deleted.",
-            player ? player->GetName() : "<unknown>", playerGuid.ToString(), itemGuid, itemEntry, mailId);
+            player ? player->GetName() : "<unknown>", playerGuid.ToString(), itemGuidDb, itemEntry, mailId);
 
         CharacterDatabaseTransaction trans = CharacterDatabase.BeginTransaction();
 
         CharacterDatabasePreparedStatement* stmt = CharacterDatabase.GetPreparedStatement(CHAR_DEL_INVALID_MAIL_ITEM);
-        stmt->SetData(0, itemGuid);
+        stmt->SetData(0, static_cast<uint64>(itemGuidDb));
         trans->Append(stmt);
 
         CharacterDatabase.CommitTransaction(trans);
@@ -6130,12 +6138,12 @@ Item* Player::_LoadMailedItem(ObjectGuid const& playerGuid, Player* player, uint
     Item* item = NewItemOrBag(proto);
 
     ObjectGuid ownerGuid = fields[13].Get<uint32>() ? ObjectGuid::Create<HighGuid::Player>(fields[13].Get<uint32>()) : ObjectGuid::Empty;
-    if (!item->LoadFromDB(itemGuid, ownerGuid, fields, itemEntry))
+    if (!item->LoadFromDB64(itemGuidDb, ownerGuid, fields, itemEntry))
     {
-        LOG_ERROR("entities.player", "Player::_LoadMailedItems: Item (GUID: {}) in mail ({}) doesn't exist, deleted from mail.", itemGuid, mailId);
+        LOG_ERROR("entities.player", "Player::_LoadMailedItems: Item (GUID: {}) in mail ({}) doesn't exist, deleted from mail.", itemGuidDb, mailId);
 
         CharacterDatabasePreparedStatement* stmt = CharacterDatabase.GetPreparedStatement(CHAR_DEL_MAIL_ITEM);
-        stmt->SetData(0, itemGuid);
+        stmt->SetData(0, static_cast<uint64>(itemGuidDb));
         CharacterDatabase.Execute(stmt);
 
         item->FSetState(ITEM_REMOVED);
@@ -6147,7 +6155,7 @@ Item* Player::_LoadMailedItem(ObjectGuid const& playerGuid, Player* player, uint
 
     if (mail)
     {
-        mail->AddItem(itemGuid, itemEntry);
+        mail->AddItem(item->GetGUID().GetCounter(), itemEntry);
     }
 
     if (player)
@@ -7271,11 +7279,11 @@ void Player::_SaveInventory(CharacterDatabaseTransaction trans)
         }
 
         stmt = CharacterDatabase.GetPreparedStatement(CHAR_DEL_CHAR_INVENTORY_BY_ITEM);
-        stmt->SetData(0, item->GetGUID().GetCounter());
+        stmt->SetData(0, static_cast<uint64>(item->GetDbGuid()));
         trans->Append(stmt);
 
         stmt = CharacterDatabase.GetPreparedStatement(CHAR_DEL_ITEM_INSTANCE);
-        stmt->SetData(0, item->GetGUID().GetCounter());
+        stmt->SetData(0, static_cast<uint64>(item->GetDbGuid()));
         trans->Append(stmt);
         m_items[i]->FSetState(ITEM_NEW);
 
@@ -7369,16 +7377,23 @@ void Player::_SaveInventory(CharacterDatabaseTransaction trans)
         {
             case ITEM_NEW:
             case ITEM_CHANGED:
+                // Ensure a DB GUID is assigned before writing character_inventory
+                if (item->GetDbGuid() == 0)
+                {
+                    uint64 newDbGuid = sItemGuidMap->AcquireDbGuid();
+                    sItemGuidMap->Bind(newDbGuid, item->GetGUID().GetCounter());
+                    item->SetDbGuid(newDbGuid);
+                }
                 stmt = CharacterDatabase.GetPreparedStatement(CHAR_REP_INVENTORY_ITEM);
                 stmt->SetData(0, lowGuid);
                 stmt->SetData(1, bag_guid);
                 stmt->SetData (2, item->GetSlot());
-                stmt->SetData(3, item->GetGUID().GetCounter());
+                stmt->SetData(3, static_cast<uint64>(item->GetDbGuid()));
                 trans->Append(stmt);
                 break;
             case ITEM_REMOVED:
                 stmt = CharacterDatabase.GetPreparedStatement(CHAR_DEL_CHAR_INVENTORY_BY_ITEM);
-                stmt->SetData(0, item->GetGUID().GetCounter());
+                stmt->SetData(0, static_cast<uint64>(item->GetDbGuid()));
                 trans->Append(stmt);
             case ITEM_UNCHANGED:
                 break;
diff --git a/src/server/game/Globals/ObjectMgr.cpp b/src/server/game/Globals/ObjectMgr.cpp
index ff904bb177..8404a9b2a0 100644
--- a/src/server/game/Globals/ObjectMgr.cpp
+++ b/src/server/game/Globals/ObjectMgr.cpp
@@ -27,6 +27,7 @@
 #include "DBCStructure.h"
 #include "DatabaseEnv.h"
 #include "DisableMgr.h"
+#include "Entities/Item/ItemGuidMap.h"
 #include "GameEventMgr.h"
 #include "GameObjectAIFactory.h"
 #include "GameTime.h"
@@ -6327,7 +6328,7 @@ void ObjectMgr::ReturnOrDeleteOldMails(bool serverUp)
         do
         {
             Field* fields = items->Fetch();
-            item.item_guid = fields[0].Get<uint32>();
+            item.item_guid = fields[0].Get<uint64>();
             item.item_template = fields[1].Get<uint32>();
             uint32 mailId = fields[2].Get<uint32>();
             itemsCache[mailId].push_back(item);
@@ -7195,14 +7196,11 @@ void ObjectMgr::SetHighestGuids()
         GetGuidSequenceGenerator<HighGuid::Player>().Set((*result)[0].Get<uint32>() + 1);
 
     result = CharacterDatabase.Query("SELECT MAX(guid) FROM item_instance");
-    if (result)
-        GetGuidSequenceGenerator<HighGuid::Item>().Set((*result)[0].Get<uint32>() + 1);
+    // Initialize persistent item DB GUID starting point (64-bit)
+    // NOTE: In decoupled mode, item low GUIDs are process-local and not persisted.
+    if (QueryResult itemMax = CharacterDatabase.Query("SELECT MAX(guid) FROM item_instance"))
+        sItemGuidMap->InitDbGuidSeed((*itemMax)[0].Get<uint64>() + 1u);
 
-    // Cleanup other tables from not existed guids ( >= _hiItemGuid)
-    CharacterDatabase.Execute("DELETE FROM character_inventory WHERE item >= '{}'", GetGuidSequenceGenerator<HighGuid::Item>().GetNextAfterMaxUsed());     // One-time query
-    CharacterDatabase.Execute("DELETE FROM mail_items WHERE item_guid >= '{}'", GetGuidSequenceGenerator<HighGuid::Item>().GetNextAfterMaxUsed());         // One-time query
-    CharacterDatabase.Execute("DELETE FROM auctionhouse WHERE itemguid >= '{}'", GetGuidSequenceGenerator<HighGuid::Item>().GetNextAfterMaxUsed());        // One-time query
-    CharacterDatabase.Execute("DELETE FROM guild_bank_item WHERE item_guid >= '{}'", GetGuidSequenceGenerator<HighGuid::Item>().GetNextAfterMaxUsed());    // One-time query
 
     result = WorldDatabase.Query("SELECT MAX(guid) FROM transports");
     if (result)
diff --git a/src/server/game/Guilds/Guild.cpp b/src/server/game/Guilds/Guild.cpp
index bd9bbafc66..77e8b9d9d8 100644
--- a/src/server/game/Guilds/Guild.cpp
+++ b/src/server/game/Guilds/Guild.cpp
@@ -387,25 +387,26 @@ void Guild::BankTab::LoadFromDB(Field* fields)
 bool Guild::BankTab::LoadItemFromDB(Field* fields)
 {
     uint8 slotId = fields[13].Get<uint8>();
-    ObjectGuid::LowType itemGuid = fields[14].Get<uint32>();
+    uint64 itemGuidDb = fields[14].Get<uint64>();
     uint32 itemEntry = fields[15].Get<uint32>();
     if (slotId >= GUILD_BANK_MAX_SLOTS)
     {
-        LOG_ERROR("guild", "Invalid slot for item (GUID: {}, id: {}) in guild bank, skipped.", itemGuid, itemEntry);
+        LOG_ERROR("guild", "Invalid slot for item (GUID: {}, id: {}) in guild bank, skipped.", itemGuidDb, itemEntry);
         return false;
     }
 
     ItemTemplate const* proto = sObjectMgr->GetItemTemplate(itemEntry);
     if (!proto)
     {
-        LOG_ERROR("guild", "Unknown item (GUID: {}, id: {}) in guild bank, skipped.", itemGuid, itemEntry);
+        LOG_ERROR("guild", "Unknown item (GUID: {}, id: {}) in guild bank, skipped.", itemGuidDb, itemEntry);
         return false;
     }
 
     Item* pItem = NewItemOrBag(proto);
-    if (!pItem->LoadFromDB(itemGuid, ObjectGuid::Empty, fields, itemEntry))
+    bool ok = pItem->LoadFromDB64(itemGuidDb, ObjectGuid::Empty, fields, itemEntry);
+    if (!ok)
     {
-        LOG_ERROR("guild", "Item (GUID {}, id: {}) not found in item_instance, deleting from guild bank!", itemGuid, itemEntry);
+        LOG_ERROR("guild", "Item (GUID {}, id: {}) not found in item_instance, deleting from guild bank!", itemGuidDb, itemEntry);
 
         CharacterDatabasePreparedStatement* stmt = CharacterDatabase.GetPreparedStatement(CHAR_DEL_NONEXISTENT_GUILD_BANK_ITEM);
         stmt->SetData(0, m_guildId);
diff --git a/src/server/game/Handlers/MailHandler.cpp b/src/server/game/Handlers/MailHandler.cpp
index 76cb7fc0d1..90a3c2a9d7 100644
--- a/src/server/game/Handlers/MailHandler.cpp
+++ b/src/server/game/Handlers/MailHandler.cpp
@@ -31,6 +31,7 @@
 #include "ScriptMgr.h"
 #include "WorldPacket.h"
 #include "WorldSession.h"
+#include "Entities/Item/ItemGuidMap.h"
 
 #define MAX_INBOX_CLIENT_CAPACITY 50
 
@@ -73,14 +74,14 @@ void WorldSession::HandleSendMail(WorldPacket& recvData)
 
     recvData >> subject;
 
+    recvData >> body;
+
     // prevent client crash
     if (subject.find("| |") != std::string::npos || body.find("| |") != std::string::npos)
     {
         return;
     }
 
-    recvData >> body;
-
     recvData >> unk1;                                      // stationery?
     recvData >> unk2;                                      // 0x00000000
 
@@ -712,7 +713,7 @@ void WorldSession::HandleGetMailList(WorldPacket& recvData)
 
         for (uint8 i = 0; i < item_count; ++i)
         {
-            Item* item = player->GetMItem(mail->items[i].item_guid);
+            Item* item = player->GetMItem(static_cast<ObjectGuid::LowType>(mail->items[i].item_guid));
             // item index (0-6?)
             data << uint8(i);
             // item guid low?
@@ -775,7 +776,7 @@ void WorldSession::HandleMailCreateTextItem(WorldPacket& recvData)
     }
 
     Item* bodyItem = new Item;                              // This is not bag and then can be used new Item.
-    if (!bodyItem->Create(sObjectMgr->GetGenerator<HighGuid::Item>().Generate(), MAIL_BODY_ITEM_TEMPLATE, player))
+    if (!bodyItem->Create(sItemGuidMap->AcquireForNew(), MAIL_BODY_ITEM_TEMPLATE, player))
     {
         delete bodyItem;
         return;
diff --git a/src/server/game/Handlers/SpellHandler.cpp b/src/server/game/Handlers/SpellHandler.cpp
index 6117637db6..aa3be2ba3c 100644
--- a/src/server/game/Handlers/SpellHandler.cpp
+++ b/src/server/game/Handlers/SpellHandler.cpp
@@ -273,7 +273,7 @@ void WorldSession::HandleOpenItemOpcode(WorldPacket& recvPacket)
         if (item->IsWrapped())// wrapped?
         {
             CharacterDatabasePreparedStatement* stmt = CharacterDatabase.GetPreparedStatement(CHAR_SEL_CHARACTER_GIFT_BY_ITEM);
-            stmt->SetData(0, item->GetGUID().GetCounter());
+            stmt->SetData(0, static_cast<uint64>(item->GetDbGuid()));
             _queryProcessor.AddCallback(CharacterDatabase.AsyncQuery(stmt)
                 .WithPreparedCallback(std::bind(&WorldSession::HandleOpenWrappedItemCallback, this, bagIndex, slot, item->GetGUID().GetCounter(), std::placeholders::_1)));
         }
@@ -318,7 +318,7 @@ void WorldSession::HandleOpenWrappedItemCallback(uint8 bagIndex, uint8 slot, Obj
     GetPlayer()->SaveInventoryAndGoldToDB(trans);
 
     CharacterDatabasePreparedStatement* stmt = CharacterDatabase.GetPreparedStatement(CHAR_DEL_GIFT);
-    stmt->SetData(0, item->GetGUID().GetCounter());
+    stmt->SetData(0, static_cast<uint64>(item->GetDbGuid()));
     trans->Append(stmt);
 
     CharacterDatabase.CommitTransaction(trans);
diff --git a/src/server/game/Mails/Mail.cpp b/src/server/game/Mails/Mail.cpp
index f8d838776f..044f0d5c53 100644
--- a/src/server/game/Mails/Mail.cpp
+++ b/src/server/game/Mails/Mail.cpp
@@ -246,7 +246,7 @@ void MailDraft::SendMailTo(CharacterDatabaseTransaction trans, MailReceiver cons
     {
         stmt = CharacterDatabase.GetPreparedStatement(CHAR_INS_MAIL_ITEM);
         stmt->SetData(0, mailId);
-        stmt->SetData(1, mailItemIter->second->GetGUID().GetCounter());
+        stmt->SetData(1, static_cast<uint64>(mailItemIter->second->GetDbGuid()));
         stmt->SetData(2, receiver.GetPlayerGUIDLow());
         trans->Append(stmt);
     }
diff --git a/src/server/game/Mails/Mail.h b/src/server/game/Mails/Mail.h
index f89a5e1271..a38bf661de 100644
--- a/src/server/game/Mails/Mail.h
+++ b/src/server/game/Mails/Mail.h
@@ -158,7 +158,7 @@ private:
 
 struct MailItemInfo
 {
-    ObjectGuid::LowType item_guid;
+    uint64 item_guid;
     uint32 item_template;
 };
 typedef std::vector<MailItemInfo> MailItemInfoVec;