diff --git a/CallbackHandler.BusinessLogic/Services/CallbackDomainService.cs b/CallbackHandler.BusinessLogic/Services/CallbackDomainService.cs
index e11ed04..41b3d1c 100644
--- a/CallbackHandler.BusinessLogic/Services/CallbackDomainService.cs
+++ b/CallbackHandler.BusinessLogic/Services/CallbackDomainService.cs
@@ -17,6 +17,7 @@ namespace CallbackHandler.BusinessLogic.Services;
 using System;
 using System.Threading;
 using System.Threading.Tasks;
+using static Microsoft.EntityFrameworkCore.DbLoggerCategory.Database;
 
 public interface ICallbackDomainService
 {
@@ -41,16 +42,34 @@ public CallbackDomainService(IAggregateRepository<CallbackMessageAggregate, Doma
     public async Task<Result> RecordCallback(CallbackCommands.RecordCallbackCommand command,
                                              CancellationToken cancellationToken) {
 
-        // split the reference string into an array of strings
-        String[] referenceData = command.Reference?.Split(['-'], StringSplitOptions.RemoveEmptyEntries) ?? [];
+        // validate the reference
+        Result<(Guid estateId, Guid merchantId)> validateResult = await ValidateReference(command.Reference, cancellationToken);
+        if (validateResult.IsFailed)
+            return ResultHelpers.CreateFailure(validateResult);
 
-        if (referenceData.Length == 0) {
-            return Result.Invalid("Reference cannot be empty.");
-        }
+        Result<CallbackMessageAggregate> getResult = await this.AggregateRepository.GetLatestVersion(command.CallbackId, cancellationToken);
+        Result<CallbackMessageAggregate> callbackMessageAggregateResult =
+            DomainServiceHelper.HandleGetAggregateResult(getResult, command.CallbackId, false);
 
-        if (referenceData.Length != 2) {
-            return Result.Invalid("Reference must contain estate and merchant references separated by a hyphen.");
-        }
+        CallbackMessageAggregate aggregate = callbackMessageAggregateResult.Data;
+        Result stateResult = aggregate.RecordCallback(command.CallbackId, command.TypeString, command.MessageFormat, command.CallbackMessage, command.Destinations,
+            (command.Reference,validateResult.Data.estateId, validateResult.Data.merchantId));
+        if (stateResult.IsFailed)
+            return stateResult;
+        return await this.AggregateRepository.SaveChanges(aggregate, cancellationToken);
+    }
+
+    private async Task<Result<(Guid estateId, Guid merchantId)>> ValidateReference(String reference, CancellationToken cancellationToken) {
+        String[] referenceData = reference?.Split(['-'], StringSplitOptions.RemoveEmptyEntries) ?? [];
+
+
+        var result = referenceData.Length switch {
+            0 => Result.Invalid("Reference cannot be empty."),
+            _ when referenceData.Length != 2 => Result.Invalid("Reference must contain estate and merchant references separated by a hyphen."),
+            _ => Result.Success()
+        };
+        if (result.IsFailed)
+            return ResultHelpers.CreateFailure(result);
 
         // Element 0 is estate reference, Element 1 is merchant reference
         String estateReference = referenceData[0];
@@ -58,7 +77,8 @@ public async Task<Result> RecordCallback(CallbackCommands.RecordCallbackCommand
 
         // Validate the reference data
         // Validate the estate and merchant references are valid GUIDs
-        if (!Guid.TryParse(estateReference, out Guid estateId) || !Guid.TryParse(merchantReference, out Guid merchantId)) {
+        if (!Guid.TryParse(estateReference, out Guid estateId) || !Guid.TryParse(merchantReference, out Guid merchantId))
+        {
             return Result.Invalid("Estate or Merchant reference is not a valid GUID.");
         }
 
@@ -67,20 +87,11 @@ public async Task<Result> RecordCallback(CallbackCommands.RecordCallbackCommand
             return ResultHelpers.CreateFailure(getTokenResult);
         this.TokenResponse = getTokenResult.Data;
 
-        Result<MerchantResponse> result = await this.TransactionProcessorClient.GetMerchant(this.TokenResponse.AccessToken, estateId, merchantId, cancellationToken);
-        if (result.IsFailed)
-            return ResultHelpers.CreateFailure(result);
-
-        Result<CallbackMessageAggregate> getResult = await this.AggregateRepository.GetLatestVersion(command.CallbackId, cancellationToken);
-        Result<CallbackMessageAggregate> callbackMessageAggregateResult =
-            DomainServiceHelper.HandleGetAggregateResult(getResult, command.CallbackId, false);
+        Result<MerchantResponse> getMerchantResult = await this.TransactionProcessorClient.GetMerchant(this.TokenResponse.AccessToken, estateId, merchantId, cancellationToken);
+        if (getMerchantResult.IsFailed)
+            return ResultHelpers.CreateFailure(getMerchantResult);
 
-        CallbackMessageAggregate aggregate = callbackMessageAggregateResult.Data;
-        Result stateResult = aggregate.RecordCallback(command.CallbackId, command.TypeString, command.MessageFormat, command.CallbackMessage, command.Destinations,
-            (command.Reference, Guid.Parse(estateReference), Guid.Parse(merchantReference)));
-        if (stateResult.IsFailed)
-            return stateResult;
-        return await this.AggregateRepository.SaveChanges(aggregate, cancellationToken);
+        return Result.Success((estateId,merchantId));
     }
 
     private TokenResponse TokenResponse;