You need to have a account at twilio.com.
I used a free trial account to make this demo application.
You need to take for you a number on that support Twilio SMS. I got one in the US to send SMS to my country.
Open your Visual Studio and create a new Project with Windows Form Application.
This will make your Windows Form with Form1.cs and Form1.cs [Design] .
You need to install with Visual Studio the twilio-csharp library.
This library lets you write C# code – go to Visual Studio menu:
Tools > NuGet Package Manager > Package Manager Console and use this command to install twilio-csharp library.
PM> Install-Package Twilio
Attempting to gather dependency information for package 'Twilio.4.7.2' with respect to project 'twilio001', targeting '.NETFramework,Version=v4.5.2'
Gathering dependency information took 737.94 ms
Attempting to resolve dependencies for package 'Twilio.4.7.2' with DependencyBehavior 'Lowest'
Resolving dependency information took 0 ms
Resolving actions to install package 'Twilio.4.7.2'
Resolved actions to install package 'Twilio.4.7.2'
Retrieving package 'Twilio 4.7.2' from 'nuget.org'.
Retrieving package 'RestSharp 105.2.2' from 'nuget.org'.
OK https://api.nuget.org/packages/restsharp.105.2.2.nupkg 70ms
Installing RestSharp 105.2.2.
OK https://api.nuget.org/packages/twilio.4.7.2.nupkg 286ms
Installing Twilio 4.7.2.
Successfully installed 'Twilio 4.7.2' to twilio001
Executing nuget actions took 10.06 sec
Time Elapsed: 00:00:13.6427227
Find the Toolbox ( Ctrl+Alt+X keys ) and add one button to your Windows Form.
Under Form1.cs [Design] press double left click with the mouse on Button ( is named button1 ).
This will open the Form1.cs and add this source code:
public partial class Form1 : Form
private void button1_Click(object sender, EventArgs e)
var accountSid = "your_account"; // Your Account SID from www.twilio.com/console
var authToken = "your_token"; // Your Auth Token from www.twilio.com/console
var twilio = new TwilioRestClient(accountSid, authToken);
var message = twilio.SendMessage(
"+1111111", // From (Replace with your Twilio number)
"+1111111", // To (Replace with your phone number)
"Hello from C# and Twilio SMS messages!"
if (message.RestException != null)
var error = message.RestException.Message;
Fill with your accountSid, authToken and your number mobile phone from your twilio account console.
Save the file Form1.cs and then Build and Run the application.
Press the button to send the SMS message and you will see this output: