diff --git a/docs/Exception-Handling.md b/docs/Exception-Handling.md
index 344447932a..32680c38f3 100644
--- a/docs/Exception-Handling.md
+++ b/docs/Exception-Handling.md
@@ -120,8 +120,11 @@ public class MyException : Exception, IExceptionWithSelfLogging
 
 There are some **conventional** exception classes you can **directly throw** or **derive** your own exception types when needed.
 
-* `BusinessException`: Indicates a business exception (rather than infrastructure exceptions). You can instead implement the `IBusinessException` interface.
-* `UserFriendlyException`: Indicates an exception that can be **directly shown to the user** (without hiding or localizing). You can instead implement the `IUserFriendlyException` interface.
+#### Business Exception
+
+Most of your own exceptions will be business exceptions. The `IBusinessException` interface is used to mark an exception as a business exception.
+
+`BusinessException` implements the `IBusinessException` interface in addition to the `IHasErrorCode`, `IHasErrorDetails` and `IHasLogLevel` interfaces. Default log level is `Warning`.
 
 ### Built-In Exceptions
 
@@ -135,4 +138,8 @@ You can also throw these type of exceptions in your code (while it's rarely need
 
 ### Exception Localization
 
-### HTTP Status Code Mapping
\ No newline at end of file
+TODO
+
+### HTTP Status Code Mapping
+
+TODO
\ No newline at end of file
diff --git a/src/Volo.Abp.UI/Volo/Abp/Ui/IUserFriendlyException.cs b/src/Volo.Abp.UI/Volo/Abp/Ui/IUserFriendlyException.cs
index 8b6b1fdc8d..25f14fb346 100644
--- a/src/Volo.Abp.UI/Volo/Abp/Ui/IUserFriendlyException.cs
+++ b/src/Volo.Abp.UI/Volo/Abp/Ui/IUserFriendlyException.cs
@@ -1,5 +1,10 @@
+using System;
+
 namespace Volo.Abp.UI
 {
+    //TODO: Remove IUserFriendlyException. Instead use IBusinessException.
+
+    [Obsolete("Use IBusinessException")]
     public interface IUserFriendlyException
     {
 
diff --git a/src/Volo.Abp.UI/Volo/Abp/Ui/UserFriendlyException.cs b/src/Volo.Abp.UI/Volo/Abp/Ui/UserFriendlyException.cs
index 058f5cd441..96dcdd3fc0 100644
--- a/src/Volo.Abp.UI/Volo/Abp/Ui/UserFriendlyException.cs
+++ b/src/Volo.Abp.UI/Volo/Abp/Ui/UserFriendlyException.cs
@@ -6,10 +6,13 @@ using Volo.Abp.Logging;
 
 namespace Volo.Abp.UI
 {
+    //TODO: Remove UserFriendlyException. Instead use BusinessException.
+
     /// <summary>
     /// This exception type is directly shown to the user.
     /// </summary>
     [Serializable]
+    [Obsolete("Use BusinessException")]
     public class UserFriendlyException : ApplicationException, 
         IUserFriendlyException, 
         IHasLogLevel, 
@@ -30,14 +33,13 @@ namespace Volo.Abp.UI
         /// Severity of the exception.
         /// Default: Warn.
         /// </summary>
-        public LogLevel LogLevel { get; set; }
+        public LogLevel LogLevel { get; set; } = LogLevel.Warning;
 
         /// <summary>
         /// Constructor.
         /// </summary>
         public UserFriendlyException()
         {
-            LogLevel = LogLevel.Warning;
         }
 
         /// <summary>
@@ -56,7 +58,6 @@ namespace Volo.Abp.UI
         public UserFriendlyException(string message)
             : base(message)
         {
-            LogLevel = LogLevel.Warning;
         }
 
         /// <summary>
@@ -89,7 +90,6 @@ namespace Volo.Abp.UI
         public UserFriendlyException(string message, Exception innerException)
             : base(message, innerException)
         {
-            LogLevel = LogLevel.Warning;
         }
 
         /// <summary>