diff --git a/src/CMSMicroservice.Application/OrderManagementCQ/Commands/CancelOrderByAdmin/CancelOrderByAdminCommandHandler.cs b/src/CMSMicroservice.Application/OrderManagementCQ/Commands/CancelOrderByAdmin/CancelOrderByAdminCommandHandler.cs
index c53ea04..2a72c7b 100644
--- a/src/CMSMicroservice.Application/OrderManagementCQ/Commands/CancelOrderByAdmin/CancelOrderByAdminCommandHandler.cs
+++ b/src/CMSMicroservice.Application/OrderManagementCQ/Commands/CancelOrderByAdmin/CancelOrderByAdminCommandHandler.cs
@@ -10,15 +10,18 @@ public class CancelOrderByAdminCommandHandler : IRequestHandler<CancelOrderByAdm
 {
     private readonly IApplicationDbContext _context;
     private readonly ICurrentUserService _currentUser;
+    private readonly IInventoryService _inventoryService;
     private readonly ILogger<CancelOrderByAdminCommandHandler> _logger;
 
     public CancelOrderByAdminCommandHandler(
         IApplicationDbContext context,
         ICurrentUserService currentUser,
+        IInventoryService inventoryService,
         ILogger<CancelOrderByAdminCommandHandler> logger)
     {
         _context = context;
         _currentUser = currentUser;
+        _inventoryService = inventoryService;
         _logger = logger;
     }
 
@@ -33,6 +36,7 @@ public class CancelOrderByAdminCommandHandler : IRequestHandler<CancelOrderByAdm
         var order = await _context.UserOrders
             .Include(x => x.User)
             .ThenInclude(x => x.UserWallets)
+            .Include(x => x.FactorDetails)
             .FirstOrDefaultAsync(x => x.Id == request.OrderId && !x.IsDeleted, cancellationToken);
 
         if (order == null)
@@ -87,6 +91,26 @@ public class CancelOrderByAdminCommandHandler : IRequestHandler<CancelOrderByAdm
 
         await _context.SaveChangesAsync(cancellationToken);
 
+        // Restore inventory for each item (only if order was not yet delivered)
+        if (order.FactorDetails != null && order.FactorDetails.Any())
+        {
+            foreach (var item in order.FactorDetails)
+            {
+                var restored = await _inventoryService.ProcessReturnAsync(
+                    item.ProductId, ProductType.RegularProduct,
+                    item.Count, order.Id,
+                    note: $"برگشت موجودی — لغو سفارش #{order.Id} توسط Admin",
+                    cancellationToken: cancellationToken);
+
+                if (!restored)
+                {
+                    _logger.LogWarning(
+                        "Failed to restore inventory for ProductId={ProductId} on cancel OrderId={OrderId}",
+                        item.ProductId, order.Id);
+                }
+            }
+        }
+
         _logger.LogInformation(
             "Order cancelled by admin. OrderId: {OrderId}, Reason: {Reason}, Refunded: {Refunded}, Admin: {AdminId}",
             order.Id,
diff --git a/src/CMSMicroservice.WebApi/Services/UserOrderService.cs b/src/CMSMicroservice.WebApi/Services/UserOrderService.cs
index c9dea29..fea1e6a 100644
--- a/src/CMSMicroservice.WebApi/Services/UserOrderService.cs
+++ b/src/CMSMicroservice.WebApi/Services/UserOrderService.cs
@@ -29,12 +29,14 @@ public class UserOrderService : UserOrderContract.UserOrderContractBase
     private readonly ISender _sender;
     private readonly IApplicationDbContext _context;
     private readonly ICurrentUserService _currentUserService;
+    private readonly IInventoryService _inventoryService;
 
-    public UserOrderService(ISender sender, IApplicationDbContext context, ICurrentUserService currentUserService)
+    public UserOrderService(ISender sender, IApplicationDbContext context, ICurrentUserService currentUserService, IInventoryService inventoryService)
     {
         _sender = sender;
         _context = context;
         _currentUserService = currentUserService;
+        _inventoryService = inventoryService;
     }
     [RequiresPermission(PermissionNames.OrdersCreate)]
     public override async Task<CreateNewUserOrderResponse> CreateNewUserOrder(CreateNewUserOrderRequest request, ServerCallContext context)
@@ -285,6 +287,18 @@ public class UserOrderService : UserOrderContract.UserOrderContractBase
             throw new RpcException(new Status(StatusCode.InvalidArgument, 
                 $"مبلغ نامعتبر است. محاسبه شده: {totalAmount}, دریافتی: {request.TotalAmount}"));
         }
+
+        // Validate stock availability for all cart items before any financial operation
+        foreach (var cartItem in cartItems)
+        {
+            var available = await _inventoryService.GetAvailableQuantityAsync(
+                cartItem.ProductId, ProductType.RegularProduct, ct: context.CancellationToken);
+            if (available < cartItem.Count)
+            {
+                throw new RpcException(new Status(StatusCode.FailedPrecondition,
+                    $"موجودی «{cartItem.Product.Title}» کافی نیست. موجود: {available}، درخواستی: {cartItem.Count}"));
+            }
+        }
         
         // Get user's wallet
         var wallet = await _context.UserWallets
@@ -461,6 +475,18 @@ public class UserOrderService : UserOrderContract.UserOrderContractBase
             cartItem.IsDeleted = true;
         }
         
+        await _context.SaveChangesAsync(context.CancellationToken);
+
+        // Deduct inventory and update SaleCount for each purchased item
+        foreach (var cartItem in cartItems)
+        {
+            await _inventoryService.ConfirmSaleAsync(
+                cartItem.ProductId, ProductType.RegularProduct,
+                cartItem.Count, order.Id, context.CancellationToken);
+
+            cartItem.Product.SaleCount += cartItem.Count;
+        }
+
         await _context.SaveChangesAsync(context.CancellationToken);
         
         return new SubmitShopBuyOrderResponse