diff --git a/src/Services/Ordering/Ordering.API/Application/DomainEventHandlers/BuyerAndPaymentMethodVerified/UpdateOrderWhenBuyerAndPaymentMethodVerifiedDomainEventHandler.cs b/src/Services/Ordering/Ordering.API/Application/DomainEventHandlers/BuyerAndPaymentMethodVerified/UpdateOrderWhenBuyerAndPaymentMethodVerifiedDomainEventHandler.cs
index ffcd4fb74..fe7e11a1e 100644
--- a/src/Services/Ordering/Ordering.API/Application/DomainEventHandlers/BuyerAndPaymentMethodVerified/UpdateOrderWhenBuyerAndPaymentMethodVerifiedDomainEventHandler.cs
+++ b/src/Services/Ordering/Ordering.API/Application/DomainEventHandlers/BuyerAndPaymentMethodVerified/UpdateOrderWhenBuyerAndPaymentMethodVerifiedDomainEventHandler.cs
@@ -7,7 +7,8 @@ using System.Threading.Tasks;
 
 namespace Ordering.API.Application.DomainEventHandlers.BuyerAndPaymentMethodVerified
 {
-    public class UpdateOrderWhenBuyerAndPaymentMethodVerifiedDomainEventHandler : IAsyncNotificationHandler<BuyerAndPaymentMethodVerifiedDomainEvent>
+    public class UpdateOrderWhenBuyerAndPaymentMethodVerifiedDomainEventHandler 
+                   : IAsyncNotificationHandler<BuyerAndPaymentMethodVerifiedDomainEvent>
     {
         private readonly IOrderRepository<Order> _orderRepository;
         private readonly ILoggerFactory _logger;
diff --git a/src/Services/Ordering/Ordering.API/Application/DomainEventHandlers/OrderStartedEvent/SendEmailToCustomerWhenOrderStartedDomainEventHandler.cs b/src/Services/Ordering/Ordering.API/Application/DomainEventHandlers/OrderStartedEvent/SendEmailToCustomerWhenOrderStartedDomainEventHandler.cs
index 1c6aaccd3..4da9439c2 100644
--- a/src/Services/Ordering/Ordering.API/Application/DomainEventHandlers/OrderStartedEvent/SendEmailToCustomerWhenOrderStartedDomainEventHandler.cs
+++ b/src/Services/Ordering/Ordering.API/Application/DomainEventHandlers/OrderStartedEvent/SendEmailToCustomerWhenOrderStartedDomainEventHandler.cs
@@ -3,10 +3,22 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
 
+using MediatR;
+using Ordering.Domain.Events;
+
 namespace Ordering.API.Application.DomainEventHandlers.OrderStartedEvent
 {
     public class SendEmailToCustomerWhenOrderStartedDomainEventHandler
-    {
-         //TO DO
+                   //: IAsyncNotificationHandler<OrderStartedDomainEvent>
+    { 
+        public SendEmailToCustomerWhenOrderStartedDomainEventHandler()
+        {
+        
+        }
+
+        //public async Task Handle(OrderStartedDomainEvent orderNotification)
+        //{
+        //    //TBD - Send email logic
+        //}
     }
 }
diff --git a/src/Services/Ordering/Ordering.API/Application/DomainEventHandlers/OrderStartedEvent/ValidateOrAddBuyerAggregateWhenOrderStartedDomainEventHandler.cs b/src/Services/Ordering/Ordering.API/Application/DomainEventHandlers/OrderStartedEvent/ValidateOrAddBuyerAggregateWhenOrderStartedDomainEventHandler.cs
index e59c66578..d243a82b6 100644
--- a/src/Services/Ordering/Ordering.API/Application/DomainEventHandlers/OrderStartedEvent/ValidateOrAddBuyerAggregateWhenOrderStartedDomainEventHandler.cs
+++ b/src/Services/Ordering/Ordering.API/Application/DomainEventHandlers/OrderStartedEvent/ValidateOrAddBuyerAggregateWhenOrderStartedDomainEventHandler.cs
@@ -8,7 +8,8 @@ using System.Threading.Tasks;
 
 namespace Ordering.API.Application.DomainEventHandlers.OrderStartedEvent
 {
-    public class ValidateOrAddBuyerAggregateWhenOrderStartedDomainEventHandler : IAsyncNotificationHandler<OrderStartedDomainEvent>
+    public class ValidateOrAddBuyerAggregateWhenOrderStartedDomainEventHandler 
+                        : IAsyncNotificationHandler<OrderStartedDomainEvent>
     {
         private readonly ILoggerFactory _logger;
         private readonly IBuyerRepository<Buyer> _buyerRepository;
@@ -21,33 +22,34 @@ namespace Ordering.API.Application.DomainEventHandlers.OrderStartedEvent
             _logger = logger ?? throw new ArgumentNullException(nameof(logger));
         }
 
-        public async Task Handle(OrderStartedDomainEvent orderNotification)
+        public async Task Handle(OrderStartedDomainEvent orderStartedEvent)
         {
-            var cardTypeId = orderNotification.CardTypeId != 0 ? orderNotification.CardTypeId : 1;
+            var cardTypeId = (orderStartedEvent.CardTypeId != 0) ? orderStartedEvent.CardTypeId : 1;
 
-            var buyerGuid = _identityService.GetUserIdentity();
-            var buyer = await _buyerRepository.FindAsync(buyerGuid);
+            var userGuid = _identityService.GetUserIdentity();
 
-            if (buyer == null)
-            {
-                buyer = new Buyer(buyerGuid);
+            var buyer = await _buyerRepository.FindAsync(userGuid);
+            bool buyerOriginallyExisted = (buyer == null) ? false : true;
+
+            if (!buyerOriginallyExisted)
+            {                
+                buyer = new Buyer(userGuid);
             }
 
-            var paymentMethod = buyer.VerifyOrAddPaymentMethod(cardTypeId,
-                $"Payment Method on {DateTime.UtcNow}",
-                orderNotification.CardNumber,
-                orderNotification.CardSecurityNumber,
-                orderNotification.CardHolderName,
-                orderNotification.CardExpiration,
-                orderNotification.Order.Id);
+            buyer.VerifyOrAddPaymentMethod(cardTypeId,
+                                           $"Payment Method on {DateTime.UtcNow}",
+                                           orderStartedEvent.CardNumber,
+                                           orderStartedEvent.CardSecurityNumber,
+                                           orderStartedEvent.CardHolderName,
+                                           orderStartedEvent.CardExpiration,
+                                           orderStartedEvent.Order.Id);
 
-            _buyerRepository.Add(buyer);
+            var buyerUpdated = buyerOriginallyExisted ? _buyerRepository.Update(buyer) : _buyerRepository.Add(buyer);
 
             await _buyerRepository.UnitOfWork
                 .SaveEntitiesAsync();
 
-            _logger.CreateLogger(nameof(ValidateOrAddBuyerAggregateWhenOrderStartedDomainEventHandler)).LogTrace($"A new payment method has been successfully added for orderId: {orderNotification.Order.Id}.");
-
+            _logger.CreateLogger(nameof(ValidateOrAddBuyerAggregateWhenOrderStartedDomainEventHandler)).LogTrace($"Buyer {buyerUpdated.Id} and related payment method were validated or updated for orderId: {orderStartedEvent.Order.Id}.");
         }
     }
 }
diff --git a/src/Services/Ordering/Ordering.API/Infrastructure/AutofacModules/MediatorModule.cs b/src/Services/Ordering/Ordering.API/Infrastructure/AutofacModules/MediatorModule.cs
index 353733df3..a6864e0ef 100644
--- a/src/Services/Ordering/Ordering.API/Infrastructure/AutofacModules/MediatorModule.cs
+++ b/src/Services/Ordering/Ordering.API/Infrastructure/AutofacModules/MediatorModule.cs
@@ -16,13 +16,15 @@ namespace Microsoft.eShopOnContainers.Services.Ordering.API.Infrastructure.Autof
         protected override void Load(ContainerBuilder builder)
         {
             builder.RegisterAssemblyTypes(typeof(IMediator).GetTypeInfo().Assembly)
-                .AsImplementedInterfaces();            
+                .AsImplementedInterfaces();
 
+            // Register all the Command classes (they implement IAsyncRequestHandler) in assembly holding the Commands
             builder.RegisterAssemblyTypes(typeof(CreateOrderCommand).GetTypeInfo().Assembly)
                 .As(o => o.GetInterfaces()
                     .Where(i => i.IsClosedTypeOf(typeof(IAsyncRequestHandler<,>)))
                     .Select(i => new KeyedService("IAsyncRequestHandler", i)));
-            
+
+            // Register all the Domain Event Handler classes (they implement IAsyncNotificationHandler<>) in assembly holding the Domain Events
             builder
                 .RegisterAssemblyTypes(typeof(ValidateOrAddBuyerAggregateWhenOrderStartedDomainEventHandler).GetTypeInfo().Assembly)
                 .Where(t => t.IsClosedTypeOf(typeof(IAsyncNotificationHandler<>)))
diff --git a/src/Services/Ordering/Ordering.Domain/AggregatesModel/BuyerAggregate/IBuyerRepository.cs b/src/Services/Ordering/Ordering.Domain/AggregatesModel/BuyerAggregate/IBuyerRepository.cs
index 2fdaaf29f..9ab3fe1a5 100644
--- a/src/Services/Ordering/Ordering.Domain/AggregatesModel/BuyerAggregate/IBuyerRepository.cs
+++ b/src/Services/Ordering/Ordering.Domain/AggregatesModel/BuyerAggregate/IBuyerRepository.cs
@@ -9,7 +9,7 @@ namespace Microsoft.eShopOnContainers.Services.Ordering.Domain.AggregatesModel.B
     public interface IBuyerRepository<T> : IRepository<T> where T : IAggregateRoot
     {
         Buyer Add(Buyer buyer);
-
+        Buyer Update(Buyer buyer);
         Task<Buyer> FindAsync(string BuyerIdentityGuid);
     }
 }
diff --git a/src/Services/Ordering/Ordering.Infrastructure/Repositories/BuyerRepository.cs b/src/Services/Ordering/Ordering.Infrastructure/Repositories/BuyerRepository.cs
index 693717dac..317581013 100644
--- a/src/Services/Ordering/Ordering.Infrastructure/Repositories/BuyerRepository.cs
+++ b/src/Services/Ordering/Ordering.Infrastructure/Repositories/BuyerRepository.cs
@@ -40,6 +40,13 @@ namespace Microsoft.eShopOnContainers.Services.Ordering.Infrastructure.Repositor
             
         }
 
+        public Buyer Update(Buyer buyer)
+        {
+            return _context.Buyers
+                    .Update(buyer)
+                    .Entity;
+        }
+
         public async Task<Buyer> FindAsync(string identity)
         {
             var buyer = await _context.Buyers