diff --git a/TransactionProcessor.BusinessLogic/EventHandling/VoucherDomainEventHandler.cs b/TransactionProcessor.BusinessLogic/EventHandling/VoucherDomainEventHandler.cs
index 188b6abc..f724ad9a 100644
--- a/TransactionProcessor.BusinessLogic/EventHandling/VoucherDomainEventHandler.cs
+++ b/TransactionProcessor.BusinessLogic/EventHandling/VoucherDomainEventHandler.cs
@@ -141,6 +141,11 @@ private async Task<String> GetVoucherOperator(Models.Voucher voucherModel,
         EstateManagementGenericContext context = await this.DbContextFactory.GetContext(voucherModel.EstateId, ConnectionStringIdentifier, cancellationToken);
 
         Database.Entities.Transaction transaction = await context.Transactions.SingleOrDefaultAsync(t => t.TransactionId == voucherModel.TransactionId, cancellationToken);
+        if (transaction == null)
+        {
+            throw new Exception($"Transaction not found Transaction Id {voucherModel.TransactionId}");
+        }
+
         Contract contract = await context.Contracts.SingleOrDefaultAsync(c => c.ContractId == transaction.ContractId, cancellationToken);
 
         return contract.Description;
diff --git a/TransactionProcessor.Repository/ITransactionProcessorReadModelRepository.cs b/TransactionProcessor.Repository/ITransactionProcessorReadModelRepository.cs
index 976074e9..10eac1b1 100644
--- a/TransactionProcessor.Repository/ITransactionProcessorReadModelRepository.cs
+++ b/TransactionProcessor.Repository/ITransactionProcessorReadModelRepository.cs
@@ -1272,7 +1272,7 @@ public async Task<Result> RecordTransactionAdditionalRequestData(TransactionDoma
 
             await context.TransactionsAdditionalRequestData.AddAsync(additionalRequestData, cancellationToken);
 
-            return await context.SaveChangesAsync(cancellationToken);
+            return await context.SaveChangesWithDuplicateHandling(cancellationToken);
         }
 
         public async Task<Result> RecordTransactionAdditionalResponseData(TransactionDomainEvents.AdditionalResponseDataRecordedEvent domainEvent,
@@ -1301,7 +1301,7 @@ public async Task<Result> RecordTransactionAdditionalResponseData(TransactionDom
 
             await context.TransactionsAdditionalResponseData.AddAsync(additionalResponseData, cancellationToken);
 
-            return await context.SaveChangesAsync(cancellationToken);
+            return await context.SaveChangesWithDuplicateHandling(cancellationToken);
         }
 
         public async Task<Result> SetTransactionAmount(TransactionDomainEvents.AdditionalRequestDataRecordedEvent domainEvent,
@@ -1374,7 +1374,7 @@ public async Task<Result> StartTransaction(TransactionDomainEvents.TransactionHa
             await context.AddAsync(t, cancellationToken);
 
             Logger.LogDebug($"Transaction Loaded with Id [{domainEvent.TransactionId}]");
-            return await context.SaveChangesAsync(cancellationToken);
+            return await context.SaveChangesWithDuplicateHandling(cancellationToken);
         }
 
         public async Task<Result> UpdateEstate(EstateDomainEvents.EstateReferenceAllocatedEvent domainEvent,
diff --git a/TransactionProcessor/appsettings.json b/TransactionProcessor/appsettings.json
index 39b6fbad..bea2041d 100644
--- a/TransactionProcessor/appsettings.json
+++ b/TransactionProcessor/appsettings.json
@@ -191,10 +191,11 @@
         "TransactionProcessor.BusinessLogic.EventHandling.ReadModelDomainEventHandler,TransactionProcessor.BusinessLogic"
       ],
       "VoucherIssuedEvent": [
+        "TransactionProcessor.BusinessLogic.EventHandling.ReadModelDomainEventHandler,TransactionProcessor.BusinessLogic",
         "TransactionProcessor.BusinessLogic.EventHandling.VoucherDomainEventHandler, TransactionProcessor.BusinessLogic",
-        "TransactionProcessor.BusinessLogic.EventHandling.TransactionDomainEventHandler, TransactionProcessor.BusinessLogic"
       ],
       "VoucherFullyRedeemedEvent": [
+        "TransactionProcessor.BusinessLogic.EventHandling.ReadModelDomainEventHandler,TransactionProcessor.BusinessLogic",
         "TransactionProcessor.BusinessLogic.EventHandling.ReadModelDomainEventHandler,TransactionProcessor.BusinessLogic"
       ],
       // Operator Domain Event Handler