diff --git a/FileProcessor.BusinessLogic/Services/FileProcessorDomainService.cs b/FileProcessor.BusinessLogic/Services/FileProcessorDomainService.cs
index 0d0dbef..1a042d4 100644
--- a/FileProcessor.BusinessLogic/Services/FileProcessorDomainService.cs
+++ b/FileProcessor.BusinessLogic/Services/FileProcessorDomainService.cs
@@ -145,7 +145,10 @@ public async Task<Result<Guid>> UploadFile(FileCommands.UploadFileCommand comman
             if (fileImportLogAggregate.IsCreated == false)
             {
                 // First file of the day so create
-                fileImportLogAggregate.CreateImportLog(command.EstateId, importLogDateTime);
+                Result result = fileImportLogAggregate.CreateImportLog(command.EstateId, importLogDateTime);
+                if (result.IsFailed) {
+                    return result;
+                }
             }
 
             // Move the file
@@ -192,7 +195,9 @@ public async Task<Result<Guid>> UploadFile(FileCommands.UploadFileCommand comman
             file.MoveTo(fileDestination, overwrite: true);
 
             // Update Import log aggregate
-            fileImportLogAggregate.AddImportedFile(fileId, command.MerchantId, command.UserId, command.FileProfileId, originalName, fileDestination, command.FileUploadedDateTime);
+            var stateResult= fileImportLogAggregate.AddImportedFile(fileId, command.MerchantId, command.UserId, command.FileProfileId, originalName, fileDestination, command.FileUploadedDateTime);
+            if (stateResult.IsFailed)
+                return stateResult;
             
             return Result.Success(fileId);
         }, importLogId, cancellationToken, false);
diff --git a/FileProcessor.FileImportLogAggregate.Tests/FileImportLogAggregateTests.cs b/FileProcessor.FileImportLogAggregate.Tests/FileImportLogAggregateTests.cs
index 8b6c762..1828e8c 100644
--- a/FileProcessor.FileImportLogAggregate.Tests/FileImportLogAggregateTests.cs
+++ b/FileProcessor.FileImportLogAggregate.Tests/FileImportLogAggregateTests.cs
@@ -1,4 +1,5 @@
 using System;
+using SimpleResults;
 using Xunit;
 
 namespace FileProcessor.FileImportLogAggregate.Tests
@@ -25,7 +26,8 @@ public void FileImportLogAggregate_CanBeCreated_IsCreated()
         public void FileImportLogAggregate_CreateImportLog_IsCreated()
         {
             FileImportLogAggregate fileImportLogAggregate = FileImportLogAggregate.Create(TestData.FileImportLogId);
-            fileImportLogAggregate.CreateImportLog(TestData.EstateId, TestData.ImportLogDateTime);
+            Result result = fileImportLogAggregate.CreateImportLog(TestData.EstateId, TestData.ImportLogDateTime);
+            result.IsSuccess.ShouldBeTrue();
 
             FileImportLog fileImportLog = fileImportLogAggregate.GetFileImportLog();
             fileImportLog.ShouldNotBeNull();
@@ -48,10 +50,8 @@ public void FileImportLogAggregate_CreateImportLog_AlreadyCreated_SilentlyHandle
             fileImportLog.EstateId.ShouldBe(TestData.EstateId);
             fileImportLog.FileImportLogDateTime.ShouldBe(TestData.ImportLogDateTime);
 
-            Should.NotThrow(() =>
-                            {
-                                fileImportLogAggregate.CreateImportLog(TestData.EstateId, TestData.ImportLogDateTime);
-                            });
+            var result = fileImportLogAggregate.CreateImportLog(TestData.EstateId, TestData.ImportLogDateTime);
+            result.IsSuccess.ShouldBeTrue();
         }
 
         [Fact]
@@ -70,14 +70,12 @@ public void FileImportLogAggregate_AddImportedFile_FileAdded()
         }
 
         [Fact]
-        public void FileImportLogAggregate_AddImportedFile_ImportLogNotCreated_ErrorThrown()
-        {
+        public void FileImportLogAggregate_AddImportedFile_ImportLogNotCreated_ErrorThrown() {
             FileImportLogAggregate fileImportLogAggregate = FileImportLogAggregate.Create(TestData.FileImportLogId);
 
-            Should.Throw<InvalidOperationException>(() =>
-                                                    {
-                                                        fileImportLogAggregate.AddImportedFile(TestData.FileId, TestData.MerchantId, TestData.UserId, TestData.FileProfileId, TestData.OriginalFileName, TestData.FilePath, TestData.FileUploadedDateTime);
-                                                    });
+            var result = fileImportLogAggregate.AddImportedFile(TestData.FileId, TestData.MerchantId, TestData.UserId, TestData.FileProfileId, TestData.OriginalFileName, TestData.FilePath, TestData.FileUploadedDateTime);
+            result.IsFailed.ShouldBeTrue();
+            result.Status.ShouldBe(ResultStatus.Invalid);
         }
 
         [Fact]
@@ -86,10 +84,9 @@ public void FileImportLogAggregate_AddImportedFile_DuplicateFileId_ErrorThrown()
             FileImportLogAggregate fileImportLogAggregate = FileImportLogAggregate.Create(TestData.FileImportLogId);
             fileImportLogAggregate.CreateImportLog(TestData.EstateId, TestData.ImportLogDateTime);
             fileImportLogAggregate.AddImportedFile(TestData.FileId, TestData.MerchantId, TestData.UserId, TestData.FileProfileId, TestData.OriginalFileName, TestData.FilePath, TestData.FileUploadedDateTime);
-            Should.Throw<InvalidOperationException>(() =>
-                                                    {
-                                                        fileImportLogAggregate.AddImportedFile(TestData.FileId, TestData.MerchantId, TestData.UserId, TestData.FileProfileId, TestData.OriginalFileName, TestData.FilePath, TestData.FileUploadedDateTime);
-                                                    });
+            Result result = fileImportLogAggregate.AddImportedFile(TestData.FileId, TestData.MerchantId, TestData.UserId, TestData.FileProfileId, TestData.OriginalFileName, TestData.FilePath, TestData.FileUploadedDateTime);
+            result.IsFailed.ShouldBeTrue();
+            result.Status.ShouldBe(ResultStatus.Invalid);
         }
     }
 }
diff --git a/FileProcessor.FileImportLogAggregate/FileImportLogAggregate.cs b/FileProcessor.FileImportLogAggregate/FileImportLogAggregate.cs
index 3414d97..c209446 100644
--- a/FileProcessor.FileImportLogAggregate/FileImportLogAggregate.cs
+++ b/FileProcessor.FileImportLogAggregate/FileImportLogAggregate.cs
@@ -1,5 +1,6 @@
 using System;
 using FileProcessor.Models;
+using SimpleResults;
 
 namespace FileProcessor.FileImportLogAggregate
 {
@@ -14,33 +15,36 @@ namespace FileProcessor.FileImportLogAggregate
     using Shared.General;
 
     public static class FileImportLogAggregateExtensions{
-        public static void CreateImportLog(this FileImportLogAggregate aggregate, Guid estateId, DateTime importLogDateTime)
+        public static Result CreateImportLog(this FileImportLogAggregate aggregate, Guid estateId, DateTime importLogDateTime)
         {
             // Silently handle a duplicate create
             if (aggregate.IsCreated)
-                return;
+                return Result.Success();
 
             ImportLogCreatedEvent importLogCreatedEvent = new ImportLogCreatedEvent(aggregate.AggregateId, estateId, importLogDateTime);
 
             aggregate.ApplyAndAppend(importLogCreatedEvent);
+            return Result.Success();
         }
         
-        public static void AddImportedFile(this FileImportLogAggregate aggregate, Guid fileId, Guid merchantId, Guid userId, Guid fileProfileId, String originalFileName, String filePath, DateTime fileUploadedDateTime)
+        public static Result AddImportedFile(this FileImportLogAggregate aggregate, Guid fileId, Guid merchantId, Guid userId, Guid fileProfileId, String originalFileName, String filePath, DateTime fileUploadedDateTime)
         {
             if (aggregate.IsCreated == false)
             {
-                throw new InvalidOperationException("Import log has not been created");
+                return Result.Invalid("Import log has not been created");
             }
 
             if (aggregate.Files.Any(f => f.FileId == fileId))
             {
-                throw new InvalidOperationException($"Duplicate file {originalFileName} detected File Id [{fileId}]");
+                return Result.Invalid($"Duplicate file {originalFileName} detected File Id [{fileId}]");
             }
 
             FileAddedToImportLogEvent fileAddedToImportLogEvent =
                 new FileAddedToImportLogEvent(aggregate.AggregateId, fileId, aggregate.EstateId, merchantId, userId, fileProfileId, originalFileName, filePath, fileUploadedDateTime);
 
             aggregate.ApplyAndAppend(fileAddedToImportLogEvent);
+
+            return Result.Success();
         }
 
         public static void PlayEvent(this FileImportLogAggregate aggregate, ImportLogCreatedEvent domainEvent)