diff --git a/CHANGELOG.md b/CHANGELOG.md
index 72df7985..cda3feb8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,8 @@
 # Change Log
+## [5.49.0](https://github.com/plivo/plivo-dotnet/tree/v5.49.0) (2024-09-30)
+**Feature - Adding new param support for Number Masking session with single party **
+- Added `create_session_with_single_party`, `virtual_number_cooloff_period` and `force_pin_authentication` attributes in Masking Session
+
 ## [5.48.1](https://github.com/plivo/plivo-dotnet/tree/v5.48.1) (2024-09-06)
 **Feature - Adding more attribute on mdr object**
 - Added `message_sent_time`, `message_updated_time` and `error-message` on get and list Message API
diff --git a/README.md b/README.md
index a7be5855..c2a4b584 100644
--- a/README.md
+++ b/README.md
@@ -12,13 +12,13 @@ You can install this SDK either by referencing the .dll file or using NuGet.
 Use the following line to install the latest SDK using the NuGet CLI.
 
 ```
-PM> Install-Package Plivo -Version 5.48.1
+PM> Install-Package Plivo -Version 5.49.0
 ```
 
 You can also use the .NET CLI to install this package as follows
 
 ```
-> dotnet add package Plivo --version 5.48.1
+> dotnet add package Plivo --version 5.49.0
 ```
 
 ## Getting started
diff --git a/src/Plivo/Plivo.csproj b/src/Plivo/Plivo.csproj
index 9b9fce3c..b3f099cc 100644
--- a/src/Plivo/Plivo.csproj
+++ b/src/Plivo/Plivo.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <TargetFrameworks>netstandard2.0;netstandard1.3</TargetFrameworks>
-    <ReleaseVersion>5.48.1</ReleaseVersion>
+    <ReleaseVersion>5.49.0</ReleaseVersion>
     <Version />
     <Authors>Plivo SDKs Team</Authors>
     <Owners>Plivo Inc.</Owners>
diff --git a/src/Plivo/Plivo.nuspec b/src/Plivo/Plivo.nuspec
index adc59aee..57815b2f 100644
--- a/src/Plivo/Plivo.nuspec
+++ b/src/Plivo/Plivo.nuspec
@@ -4,7 +4,7 @@
     <summary>A .NET SDK to make voice calls and send SMS using Plivo and to generate Plivo XML</summary>
     <description>A .NET SDK to make voice calls and send SMS using Plivo and to generate Plivo XML</description>
     <id>Plivo</id>
-    <version>5.48.1</version>
+    <version>5.49.0</version>
     <title>Plivo</title>
     <authors>Plivo SDKs Team</authors>
     <owners>Plivo, Inc.</owners>
diff --git a/src/Plivo/Resource/MaskingSession/MaskingSession.cs b/src/Plivo/Resource/MaskingSession/MaskingSession.cs
index 9c121798..924fc65f 100644
--- a/src/Plivo/Resource/MaskingSession/MaskingSession.cs
+++ b/src/Plivo/Resource/MaskingSession/MaskingSession.cs
@@ -29,7 +29,7 @@ public async Task<AsyncResponse> DeleteAsync(string Id)
 
 
         #region Update
-        public MaskingSessionUpdateResponse<MaskingSession> Update(string sessionUuid, uint? session_expiry = null, uint? call_time_limit = null, 
+        public MaskingSessionUpdateResponse<MaskingSession> Update(string sessionUuid, string first_party = null, string second_party = null, uint? session_expiry = null, uint? call_time_limit = null, 
         bool? record = null, string record_file_format = null, string recording_callback_url = null, string callback_url = null, 
         string callback_method = null, uint? ring_timeout = null, string first_party_play_url = null, string second_party_play_url = null, 
         string recording_callback_method = null, string subaccount = null, bool? geomatch = null
@@ -37,13 +37,13 @@ public MaskingSessionUpdateResponse<MaskingSession> Update(string sessionUuid, u
         {
             var updateResponse =
                 ((MaskingSessionInterface) Interface)
-                .Update(Id, session_expiry, call_time_limit, record, record_file_format, recording_callback_url, callback_url, 
+                .Update(Id, first_party, second_party, session_expiry, call_time_limit, record, record_file_format, recording_callback_url, callback_url, 
                 callback_method, ring_timeout, first_party_play_url, second_party_play_url, recording_callback_method, 
                 subaccount, geomatch);
             return updateResponse;
         }
 
-        public async Task<AsyncResponse> UpdateAsync(string sessionUuid, uint? session_expiry = null, uint? call_time_limit = null, 
+        public async Task<AsyncResponse> UpdateAsync(string sessionUuid, string first_party = null, string second_party = null,  uint? session_expiry = null, uint? call_time_limit = null, 
         bool? record = null, string record_file_format = null, string recording_callback_url = null, string callback_url = null, 
         string callback_method = null, uint? ring_timeout = null, string first_party_play_url = null, string second_party_play_url = null, 
         string recording_callback_method = null, string subaccount = null, bool? geomatch = null
@@ -51,7 +51,7 @@ public async Task<AsyncResponse> UpdateAsync(string sessionUuid, uint? session_e
         {
             var updateResponse = await
                 ((MaskingSessionInterface)Interface)
-                .UpdateAsync(Id, session_expiry, call_time_limit, record, record_file_format, recording_callback_url, callback_url, 
+                .UpdateAsync(Id, first_party, second_party, session_expiry, call_time_limit, record, record_file_format, recording_callback_url, callback_url, 
                 callback_method, ring_timeout, first_party_play_url, second_party_play_url, recording_callback_method, 
                 subaccount, geomatch);
 
diff --git a/src/Plivo/Resource/MaskingSession/MaskingSessionInterface.cs b/src/Plivo/Resource/MaskingSession/MaskingSessionInterface.cs
index 0eead7f5..2be28f31 100644
--- a/src/Plivo/Resource/MaskingSession/MaskingSessionInterface.cs
+++ b/src/Plivo/Resource/MaskingSession/MaskingSessionInterface.cs
@@ -15,16 +15,17 @@ public MaskingSessionInterface(HttpClient client) : base(client)
 
         #region Create
         public MaskingSessionCreateResponse Create(
-            string firstParty, string secondParty, uint? sessionExpiry = null, uint? callTimeLimit = null,
+            string firstParty = null, string secondParty = null, uint? sessionExpiry = null, uint? callTimeLimit = null,
             bool? record = null, string recordFileFormat = null, string recordingCallbackUrl = null, bool? initiateCallToFirstParty = null,
             string callbackUrl = null, string callbackMethod = null, uint? ringTimeout = null, string firstPartyPlayUrl = null, 
             string secondPartyPlayUrl = null, string recordingCallbackMethod = null, bool? isPinAuthenticationRequired = null, 
             bool? generatePin = null, uint? generatePinLength = null, string firstPartyPin = null, string secondPartyPin = null, 
             string pinPromptPlay = null, uint? pinRetry = null, uint? pinRetryWait = null, string incorrectPinPlay = null, 
-            string unknownCallerPlay = null, string subaccount = null, bool? geomatch = null
+            string unknownCallerPlay = null, string subaccount = null, bool? geomatch = null, bool? forcePinAuthentication = null,
+            bool? createSessionWithSingleParty= null, uint? virtualNumberCooloffPeriod = 0
             )
         {
-            var mandatoryParams = new List<string> { "firstParty", "secondParty" };
+            var mandatoryParams = new List<string> {  };
             bool isVoiceRequest = true;
             var data = CreateData(
                 mandatoryParams,
@@ -56,7 +57,10 @@ public MaskingSessionCreateResponse Create(
                     unknownCallerPlay,
                     subaccount,
                     geomatch,
-                    isVoiceRequest
+                    isVoiceRequest,
+                    forcePinAuthentication,
+                    createSessionWithSingleParty,
+                    virtualNumberCooloffPeriod
                 });
 
             return ExecuteWithExceptionUnwrap(() =>
@@ -68,16 +72,17 @@ public MaskingSessionCreateResponse Create(
         }
 
         public async Task<AsyncResponse> CreateAsync(
-            string firstParty, string secondParty, uint? sessionExpiry = null, uint? callTimeLimit = null,
+            string firstParty = null, string secondParty = null, uint? sessionExpiry = null, uint? callTimeLimit = null,
             bool? record = null, string recordFileFormat = null, string recordingCallbackUrl = null, bool? initiateCallToFirstParty = null,
             string callbackUrl = null, string callbackMethod = null, uint? ringTimeout = null, string firstPartyPlayUrl = null, 
             string secondPartyPlayUrl = null, string recordingCallbackMethod = null, bool? isPinAuthenticationRequired = null, 
             bool? generatePin = null, uint? generatePinLength = null, string firstPartyPin = null, string secondPartyPin = null, 
             string pinPromptPlay = null, uint? pinRetry = null, uint? pinRetryWait = null, string incorrectPinPlay = null, 
-            string unknownCallerPlay = null, string subaccount = null, bool? geomatch = null
+            string unknownCallerPlay = null, string subaccount = null, bool? geomatch = null, bool? forcePinAuthentication = null,
+            bool? createSessionWithSingleParty= null, uint? virtualNumberCooloffPeriod = 0
             )
         {
-            var mandatoryParams = new List<string> { "firstParty", "secondParty" };
+            var mandatoryParams = new List<string> {  };
             bool isVoiceRequest = true;
             var data = CreateData(
                 mandatoryParams,
@@ -109,7 +114,10 @@ public async Task<AsyncResponse> CreateAsync(
                     unknownCallerPlay,
                     subaccount,
                     geomatch,
-                    isVoiceRequest
+                    isVoiceRequest,
+                    forcePinAuthentication,
+                    createSessionWithSingleParty,
+                    virtualNumberCooloffPeriod
                 });
 
             var result = Task.Run(async () => await Client.Update<AsyncResponse>(Uri, data).ConfigureAwait(false)).Result;
@@ -278,7 +286,7 @@ public async Task<AsyncResponse> DeleteAsync(string sessionUuid)
 
 
         #region Update
-        public MaskingSessionUpdateResponse<MaskingSession> Update(string sessionUuid, uint? sessionExpiry = null, uint? callTimeLimit = null, 
+        public MaskingSessionUpdateResponse<MaskingSession> Update(string sessionUuid,  string firstParty = null, string secondParty = null, uint? sessionExpiry = null, uint? callTimeLimit = null, 
         bool? record = null, string recordFileFormat = null, string recordingCallbackUrl = null, string callbackUrl = null, 
         string callbackMethod = null, uint? ringTimeout = null, string firstPartyPlayUrl = null, string secondPartyPlayUrl = null, 
         string recordingCallbackMethod = null, string subaccount = null, bool? geomatch = null
@@ -289,7 +297,8 @@ public MaskingSessionUpdateResponse<MaskingSession> Update(string sessionUuid, u
             var data = CreateData(
                 mandatoryParams,
                 new
-                {
+                {   firstParty, 
+                    secondParty,
                     sessionExpiry,
                     callTimeLimit,
                     record,
@@ -316,7 +325,7 @@ public MaskingSessionUpdateResponse<MaskingSession> Update(string sessionUuid, u
             });
         }
 
-        public async Task<AsyncResponse> UpdateAsync(string sessionUuid, uint? sessionExpiry = null, uint? callTimeLimit = null, 
+        public async Task<AsyncResponse> UpdateAsync(string sessionUuid,  string firstParty = null, string secondParty = null, uint? sessionExpiry = null, uint? callTimeLimit = null, 
         bool? record = null, string recordFileFormat = null, string recordingCallbackUrl = null, string callbackUrl = null, 
         string callbackMethod = null, uint? ringTimeout = null, string firstPartyPlayUrl = null, string secondPartyPlayUrl = null, 
         string recordingCallbackMethod = null, string subaccount = null, bool? geomatch = null
@@ -327,7 +336,8 @@ public async Task<AsyncResponse> UpdateAsync(string sessionUuid, uint? sessionEx
             var data = CreateData(
                 mandatoryParams,
                 new
-                {
+                {   firstParty,
+                    secondParty,
                     sessionExpiry,
                     callTimeLimit,
                     record,
diff --git a/src/Plivo/Resource/ResourceInterface.cs b/src/Plivo/Resource/ResourceInterface.cs
index c2c87ff9..417eeb39 100755
--- a/src/Plivo/Resource/ResourceInterface.cs
+++ b/src/Plivo/Resource/ResourceInterface.cs
@@ -208,9 +208,12 @@ public static Dictionary<string, object> CreateData (List<string> propertyInfos,
             var dict = new Dictionary<string, object> ();
             foreach (PropertyInfo pi in data.GetType ().GetProperties ()) {
                 if (propertyInfos.Contains (pi.Name)) {
-                    if (string.IsNullOrEmpty (pi.GetValue (data)))
-                        throw new PlivoValidationException (pi.Name + " is mandatory, can not be null or empty");
+                    var propertyValue = pi.GetValue(data);
+                    if (pi.Name != "firstParty" && pi.Name != "secondParty" && string.IsNullOrEmpty(propertyValue)) 
+                            throw new PlivoValidationException(pi.Name + " is mandatory, can not be null or empty");
                 }
+                
+
 
                 if (pi.Name.Equals ("limit")) {
                     if (pi.GetValue (data) > 20) {
diff --git a/src/Plivo/Version.cs b/src/Plivo/Version.cs
index 61ff406c..8c735034 100644
--- a/src/Plivo/Version.cs
+++ b/src/Plivo/Version.cs
@@ -10,7 +10,7 @@ public class Version
         /// <summary>
         /// DotNet SDK version
         /// </summary>
-        public const string SdkVersion = "5.48.1";
+        public const string SdkVersion = "5.49.0";
         /// <summary>
         /// Plivo API version
         /// </summary>
diff --git a/tests/Plivo.Test/Mocks/maskingSessionCreateResponse.json b/tests/Plivo.Test/Mocks/maskingSessionCreateResponse.json
new file mode 100644
index 00000000..6a2bebcf
--- /dev/null
+++ b/tests/Plivo.Test/Mocks/maskingSessionCreateResponse.json
@@ -0,0 +1,48 @@
+{
+    "api_id": "e0218e45-53f5-435b-83d2-936010e40acc",
+    "session_uuid": "1091db69-2290-4633-9222-c9473c4815b6",
+    "virtual_number": "+919988776676",
+    "message": "Session created",
+    "session": {
+        "first_party": "916303955747",
+        "second_party": "916384780853",
+        "virtual_number": "919988776676",
+        "status": "active",
+        "initiate_call_to_first_party": false,
+        "session_uuid": "1091db69-2290-4633-9222-c9473c4815b6",
+        "callback_url": "",
+        "callback_method": "POST",
+        "created_time": "2024-09-05 06:43:26 +0000 UTC",
+        "modified_time": "2024-09-05 06:43:26 +0000 UTC",
+        "expiry_time": "2024-09-05 06:46:46 +0000 UTC",
+        "duration": 200,
+        "amount": 0,
+        "call_time_limit": 14400,
+        "ring_timeout": 45,
+        "first_party_play_url": "",
+        "second_party_play_url": "",
+        "record": false,
+        "record_file_format": "mp3",
+        "recording_callback_url": "",
+        "recording_callback_method": "POST",
+        "interaction": null,
+        "total_call_amount": 0,
+        "total_call_count": 0,
+        "total_call_billed_duration": 0,
+        "total_session_amount": 0,
+        "last_interaction_time": "",
+        "unknown_caller_play": "https://file-examples.com/storage/fefda3519566d3360a0efb3/2017/11/file_example_MP3_700KB.mp3",
+        "is_pin_authentication_required": true,
+        "generate_pin": false,
+        "generate_pin_length": 4,
+        "first_party_pin": "1234",
+        "second_party_pin": "4321",
+        "pin_prompt_play": "https://file-examples.com/storage/fefda3519566d3360a0efb3/2017/11/file_example_MP3_700KB.mp3",
+        "pin_retry": 2,
+        "pin_retry_wait": 7,
+        "incorrect_pin_play": "https://file-examples.com/storage/fefda3519566d3360a0efb3/2017/11/file_example_MP3_700KB.mp3",
+        "create_session_with_single_party": null,
+        "virtual_number_cooloff_period": 3500,
+        "force_pin_authentication": true
+    }
+}
\ No newline at end of file
diff --git a/version.json b/version.json
index 8fc43f46..60d2f66b 100644
--- a/version.json
+++ b/version.json
@@ -1,5 +1,5 @@
 {
-  "version": "5.48.1",
+  "version": "5.49.0",
   "publicReleaseRefSpec": [
     "^refs/heads/master$",
     "^refs/heads/v\\d+(?:\\.\\d+)?$"