diff --git a/Api/Api.csproj b/Api/Api.csproj
index ca1d4b8..b97550a 100644
--- a/Api/Api.csproj
+++ b/Api/Api.csproj
@@ -26,4 +26,8 @@
     <ProjectReference Include="..\Infrastructure\Persistence\Persistence.csproj" />
   </ItemGroup>
 
+  <ItemGroup>
+    <Folder Include="Extensions\" />
+  </ItemGroup>
+
 </Project>
diff --git a/Api/Controllers/UserController.cs b/Api/Controllers/UserController.cs
index dac9501..d8cad93 100644
--- a/Api/Controllers/UserController.cs
+++ b/Api/Controllers/UserController.cs
@@ -45,22 +45,21 @@ public IActionResult GetAllCourses()
         [HttpPut("RateCourse")]
         public async Task<IActionResult> RateCourse(RateCourseRequest request)
         {
-            try
-            {
-                return Ok(await _userService.RateCourseAsync(request));
-            }
-            catch (Exception exception)
-            {
-                return BadRequest(exception.Message);
-            }
+            return Ok(await _userService.RateCourseAsync(request));
         }
 
         [HttpPost("MakeComment")]
         public async Task<IActionResult> MakeComment(MakeCommentRequest request)
+        {
+            return Ok(await _userService.MakeCommentAsync(request));
+        }
+
+        [HttpGet("GetMyComments")]
+        public IActionResult GetMyComments(string userId)
         {
             try
             {
-                return Ok(await _userService.MakeCommentAsync(request));
+                return Ok(_userService.GetMyComments(userId));
             }
             catch (Exception exception)
             {
@@ -68,13 +67,12 @@ public async Task<IActionResult> MakeComment(MakeCommentRequest request)
             }
         }
 
-
-        [HttpGet("GetMyComments")]
-        public IActionResult GetMyComments(string userId)
+        [HttpPut("AddCourseToFavourites")]
+        public IActionResult AddCourseToFavourites(AddCourseToFavRequest request)
         {
             try
             {
-                return Ok(_userService.GetMyComments(userId));
+                return Ok(_userService.AddCourseToFavourites(request));
             }
             catch (Exception exception)
             {
diff --git a/Api/GlobalException/GlobalExceptionHandler.cs b/Api/GlobalException/GlobalExceptionHandler.cs
new file mode 100644
index 0000000..52626f4
--- /dev/null
+++ b/Api/GlobalException/GlobalExceptionHandler.cs
@@ -0,0 +1,22 @@
+using Application.Exceptions;
+using Microsoft.AspNetCore.Diagnostics;
+
+namespace Api.GlobalException;
+
+public class GlobalExceptionHandler : IExceptionHandler
+{
+    public  async ValueTask<bool> TryHandleAsync(HttpContext httpContext, Exception exception, CancellationToken cancellationToken)
+    {
+        (int statusCode, string errorMessage) = exception switch
+        {
+            InvalidRatingException => (StatusCodes.Status406NotAcceptable, "Rating must be between 1 and 5, Please provide correct number"),
+            UserNotFoundException => (StatusCodes.Status404NotFound, "Cannot find user, check user credentials"),
+            CourseNotFoundException => (StatusCodes.Status404NotFound, "Cannot find course, check course credentials"),
+            _ => (500, "Error occured, Try again.")
+        }; ; 
+
+        httpContext.Response.StatusCode = statusCode;
+        await httpContext.Response.WriteAsJsonAsync(errorMessage);
+        return true;
+    }
+}
diff --git a/Api/Program.cs b/Api/Program.cs
index df94bba..0fa44fd 100644
--- a/Api/Program.cs
+++ b/Api/Program.cs
@@ -1,4 +1,5 @@
 using Api.Extensions;
+using Api.GlobalException;
 using Application.Models.Configurations;
 using Microsoft.EntityFrameworkCore;
 using Persistence.Context;
@@ -15,6 +16,7 @@
 builder.Services.AddRepositories();
 builder.Services.AddAuthenticationAndAuthorization(builder.Configuration);
 builder.Services.AddSwagger();
+builder.Services.AddExceptionHandler<GlobalExceptionHandler>();
 var cosmos = new CosmosConfiguration();
 builder.Configuration.GetSection("Cosmos").Bind(cosmos);
 builder.Services.Configure<BlobStorageConfiguration>(builder.Configuration.GetSection("BlobStorage"));
@@ -31,6 +33,8 @@
 
 app.UseHttpsRedirection();
 
+app.UseExceptionHandler("/err");
+
 app.UseAuthorization();
 
 app.MapControllers();
diff --git a/Core/Application/Application.csproj b/Core/Application/Application.csproj
index 34ff80f..34320df 100644
--- a/Core/Application/Application.csproj
+++ b/Core/Application/Application.csproj
@@ -8,6 +8,8 @@
 
   <ItemGroup>
     <PackageReference Include="Azure.Storage.Blobs" Version="12.20.0" />
+    <PackageReference Include="Microsoft.AspNetCore" Version="2.2.0" />
+    <PackageReference Include="Microsoft.AspNetCore.Diagnostics" Version="2.2.0" />
     <PackageReference Include="Microsoft.AspNetCore.Http" Version="2.2.2" />
     <PackageReference Include="Microsoft.EntityFrameworkCore" Version="8.0.4" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Cosmos" Version="8.0.4" />
diff --git a/Core/Application/Exceptions/CourseNotFoundException.cs b/Core/Application/Exceptions/CourseNotFoundException.cs
new file mode 100644
index 0000000..9e9dbce
--- /dev/null
+++ b/Core/Application/Exceptions/CourseNotFoundException.cs
@@ -0,0 +1,9 @@
+namespace Application.Exceptions;
+
+public class CourseNotFoundException : Exception
+{
+    public CourseNotFoundException():base()
+    {
+        
+    }
+}
diff --git a/Core/Application/Exceptions/InvalidRatingException.cs b/Core/Application/Exceptions/InvalidRatingException.cs
index f878df7..46b5140 100644
--- a/Core/Application/Exceptions/InvalidRatingException.cs
+++ b/Core/Application/Exceptions/InvalidRatingException.cs
@@ -2,11 +2,8 @@
 
 public class InvalidRatingException : Exception
 {
-    public InvalidRatingException(string? message) : base(message)
-    {
-    }
-
-    public InvalidRatingException(string? message, Exception? innerException) : base(message, innerException)
+    public InvalidRatingException()
     {
+        
     }
 }
diff --git a/Core/Application/Exceptions/UserNotFoundException.cs b/Core/Application/Exceptions/UserNotFoundException.cs
new file mode 100644
index 0000000..60e88c3
--- /dev/null
+++ b/Core/Application/Exceptions/UserNotFoundException.cs
@@ -0,0 +1,12 @@
+namespace Application.Exceptions;
+
+public class UserNotFoundException : Exception
+{
+    public UserNotFoundException(string? message) : base(message)
+    {
+    }
+
+    public UserNotFoundException(string? message, Exception? innerException) : base(message, innerException)
+    {
+    }
+}
diff --git a/Core/Application/Models/Requests/AddCourseToFavRequest.cs b/Core/Application/Models/Requests/AddCourseToFavRequest.cs
new file mode 100644
index 0000000..f78bcc4
--- /dev/null
+++ b/Core/Application/Models/Requests/AddCourseToFavRequest.cs
@@ -0,0 +1,8 @@
+namespace Application.Models.Requests;
+
+public class AddCourseToFavRequest
+{
+    public string CourseId { get; set; }
+    public string UserId { get; set; }
+
+}
diff --git a/Core/Application/Services/IHostService.cs b/Core/Application/Services/IHostService.cs
index 4818c3a..49e3f99 100644
--- a/Core/Application/Services/IHostService.cs
+++ b/Core/Application/Services/IHostService.cs
@@ -11,6 +11,5 @@ public interface IHostService
     Task<bool> RemoveCourseAsync(string courseId);
 
     Task<bool> BanUser(string userId);
-
     Task<bool> ConfirmAndRemoveAccount(RemoveMyAccountRequest request);
 }
diff --git a/Core/Application/Services/IUserService.cs b/Core/Application/Services/IUserService.cs
index 4300ab0..b796c01 100644
--- a/Core/Application/Services/IUserService.cs
+++ b/Core/Application/Services/IUserService.cs
@@ -10,4 +10,5 @@ public interface IUserService
     IEnumerable<BookInfo> GetAllBooks();
     Task<bool> RateCourseAsync(RateCourseRequest request);
     Task<bool> MakeCommentAsync(MakeCommentRequest request);
+    Task<bool> AddCourseToFavourites(AddCourseToFavRequest request);
 }
diff --git a/Infrastructure/Infrastructure/Services/UserService.cs b/Infrastructure/Infrastructure/Services/UserService.cs
index 1284755..cbc9e62 100644
--- a/Infrastructure/Infrastructure/Services/UserService.cs
+++ b/Infrastructure/Infrastructure/Services/UserService.cs
@@ -89,7 +89,7 @@ public async Task<bool> MakeCommentAsync(MakeCommentRequest request)
         var course = await _unitOfWork.ReadCourseRepository.GetAsync(request.CourseId);
 
         if (user == null || course == null)
-            return false;
+            throw new UserNotFoundException("Cannot find user");
 
         var newComment = CreateNewComment(request);
 
@@ -111,16 +111,10 @@ private async Task<bool> AddNewComment(Comment newComment)
     public async Task<bool> RateCourseAsync(RateCourseRequest request)
     {
         if (request.Rate > 5 || request.Rate < 1) 
-        {
-            throw new InvalidRatingException("The rating value must be between 1 and 5. Please provide a valid rating.");
-        }
-
-        var course = await _unitOfWork.ReadCourseRepository.GetAsync(request.CourseId);
+            throw new InvalidRatingException();
 
-        if (course is null)
-        {
-            throw new ArgumentNullException(nameof(course));
-        }
+        var course = await _unitOfWork.ReadCourseRepository.GetAsync(request.CourseId)??
+            throw new CourseNotFoundException();
 
         course.Rating = course.RatingsCount == 0 ? request.Rate : (course.Rating + request.Rate) / course.RatingsCount++;
         var result = _unitOfWork.WriteCourseRepository.Update(course);
@@ -128,6 +122,23 @@ public async Task<bool> RateCourseAsync(RateCourseRequest request)
         return result;
     }
 
+    public async Task<bool> AddCourseToFavourites(AddCourseToFavRequest request)
+    {
+        var course = await _unitOfWork.ReadCourseRepository.GetAsync(request.CourseId) ?? throw new NullReferenceException();
+        course.FavCount++;
+
+        var user = await _unitOfWork.ReadUserRepository.GetAsync(request.UserId);
+        user.FavouritesIds.Add(course.Id);
+
+        await _unitOfWork.WriteUserRepository.UpdateAsync(user.Id);
+        await _unitOfWork.WriteCourseRepository.UpdateAsync(course.Id);
+
+        await _unitOfWork.WriteUserRepository.SaveChangesAsync();
+
+        return true;
+    }
+
+
     // Helper Methods
 
     private Comment CreateNewComment(MakeCommentRequest request)
@@ -147,5 +158,4 @@ private void UpdateUserAndCourseComments(User user, Course course, Comment newCo
         user.CommentIds.Add(newComment.Id);
         course.CommentIds.Add(newComment.Id);
     }
-
 }