---
title: "How to Implement “Send SMS on Mobile” Using .NET"  
description: "Sending SMS messages from a .NET application is a common requirement for: OTP verification Login authentication Notifications Alerts Marketing campaigns"  
author: "Anubhav Sharma"  
published: 2026-05-06  
updated: 2026-05-07  
canonical: https://answers.mindstick.com/blog/267/how-to-implement-send-sms-on-mobile-using-dot-net  
category: "software"  
tags: ["software", ".net programming"]  
reading_time: 4 minutes  

---

# How to Implement “Send SMS on Mobile” Using .NET

Sending SMS messages from a .NET application is a common requirement for:

- OTP verification
- Login [authentication](https://www.mindstick.com/blog/177/authentication-and-authorization-in-asp-dot-net)
- Notifications
- Alerts
- [Marketing campaigns](https://www.mindstick.com/blog/304914/how-to-utilize-analytics-for-improved-marketing-campaigns)
- Appointment reminders

In this blog, we’ll build a simple SMS sending feature using .NET and an SMS gateway API.

![How to Implement “Send SMS on Mobile” Using .NET](https://answers.mindstick.com/blogs/14f4c175-b0f6-4658-9de1-e9a4730b5d7c/images/c2190a63-6b36-4af2-816d-6457f2699bb9.jpg)

## Prerequisites

Before starting, make sure you have:

- [Visual Studio](https://www.mindstick.com/articles/12378/visual-studio-for-mac-is-out-of-beta-preview-now-officially-available) installed
- .NET 6/7/8 SDK
- Internet connection
- SMS provider account (Twilio, Fast2SMS, TextLocal, etc.)

For this tutorial, we’ll use:

- [ASP.NET Core](https://www.mindstick.com/articles/326150/asp-dot-net-core-why-it-is-best-suited-for-banking-and-finance-sectors) [Web API](https://www.mindstick.com/articles/324352/how-to-create-web-api-in-dot-net-core-3-1-mvc)
- Twilio SMS API

## Step 1: Create a New .NET Project

Open terminal or Visual Studio.

Create a new Web API project:

```plaintext
dotnet new webapi -n SmsSenderApp
```

Move into the project folder:

```plaintext
cd SmsSenderApp
```

## Step 2: Install Twilio Package

Install the Twilio NuGet package:

```plaintext
dotnet add package Twilio
```

## Step 3: Create a Twilio Account

Go to:

- [Twilio](https://www.twilio.com/?utm_source=chatgpt.com)
- After signup, collect:
- Account SID
- Auth Token
- Twilio Phone Number

## Step 4: Configure App Settings

Open `appsettings.json`.

Add:

```plaintext
{
  "Twilio": {
    "AccountSid": "YOUR_ACCOUNT_SID",
    "AuthToken": "YOUR_AUTH_TOKEN",
    "PhoneNumber": "+1234567890"
  }
}
```

## Step 5: Create SMS Service

Create a folder named:

```plaintext
Services
```

Inside it, create:

```plaintext
SmsService.cs
```

Add the following code:

```cs
using Twilio;
using Twilio.Rest.Api.V2010.Account;
using Twilio.Types;

namespace SmsSenderApp.Services
{
    public class SmsService
    {
        private readonly IConfiguration _configuration;

        public SmsService(IConfiguration configuration)
        {
            _configuration = configuration;
        }

        public async Task<string> SendSms(string to, string message)
        {
            var accountSid = _configuration["Twilio:AccountSid"];
            var authToken = _configuration["Twilio:AuthToken"];
            var fromNumber = _configuration["Twilio:PhoneNumber"];

            TwilioClient.Init(accountSid, authToken);

            var result = await MessageResource.CreateAsync(
                body: message,
                from: new PhoneNumber(fromNumber),
                to: new PhoneNumber(to)
            );

            return result.Sid;
        }
    }
}
```

## Step 6: Register the Service

Open `Program.cs`.

Add this line:

```cs
builder.Services.AddScoped<SmsService>();
```

Example:

```cs
var builder = WebApplication.CreateBuilder(args);

builder.Services.AddControllers();
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();

builder.Services.AddScoped<SmsService>();

var app = builder.Build();
```

## Step 7: Create SMS Controller

Create a controller:

```plaintext
Controllers/SmsController.cs
```

Add the following code:

```cs
using Microsoft.AspNetCore.Mvc;
using SmsSenderApp.Services;

namespace SmsSenderApp.Controllers
{
    [ApiController]
    [Route("api/[controller]")]
    public class SmsController : ControllerBase
    {
        private readonly SmsService _smsService;

        public SmsController(SmsService smsService)
        {
            _smsService = smsService;
        }

        [HttpPost("send")]
        public async Task<IActionResult> SendSms(string mobile, string message)
        {
            var response = await _smsService.SendSms(mobile, message);

            return Ok(new
            {
                Success = true,
                MessageId = response
            });
        }
    }
}
```

## Step 8: Run the Application

Run the application:

```plaintext
dotnet run
```

Swagger will open automatically.

Test API:

```plaintext
POST /api/sms/send
```

Example request:

```plaintext
mobile=+919876543210
message=Hello from .NET SMS Service
```

## Step 9: Successful SMS Response

Example response:

```plaintext
{
  "success": true,
  "messageId": "SMXXXXXXXXXXXXXXXX"
}
```

## Complete Project Structure

```plaintext
SmsSenderApp
│
├── Controllers
│   └── SmsController.cs
│
├── Services
│   └── SmsService.cs
│
├── appsettings.json
├── Program.cs
```

## Security Best Practices

Never:

- Hardcode credentials
- Expose Auth Tokens publicly
- Commit secrets to GitHub

Use:

- [Environment variables](https://www.mindstick.com/forum/159994/how-to-set-up-and-use-environment-variables-in-a-node-js-application)
- Azure Key Vault
- Secret Manager

Example:

```plaintext
dotnet user-secrets init
```

## Sending OTP SMS

Example OTP generation:

```cs
Random random = new Random();
int otp = random.Next(100000, 999999);
```

Send:

```cs
await _smsService.SendSms(
    "+919876543210",
    $"Your OTP is: {otp}"
);
```

## Alternative SMS Providers

You can also integrate:

| Provider | Best For |
| --- | --- |
| Twilio | Global SMS |
| Fast2SMS | India |
| TextLocal | OTP & alerts |
| MSG91 | Indian businesses |
| AWS SNS | Enterprise systems |

## Advantages of SMS Integration

- Fast [communication](https://www.mindstick.com/articles/126321/5-fails-and-fixes-of-the-office-communication)
- Better customer engagement
- Secure OTP verification
- Real-time alerts
- Works without internet on phones

## Conclusion

Implementing SMS [functionality](https://www.mindstick.com/blog/136/using-watermark-functionality-in-textbox-by-jquery) in .NET is simple using modern SMS APIs like Twilio. By creating a reusable SMS service, you can integrate:

- OTP systems
- Login verification
- [Notification](https://www.mindstick.com/blog/205/property-notification-in-c-sharp) systems
- Marketing alerts
- Appointment reminders

With just a few lines of code, your .NET application can send SMS messages globally in real time.

---

Original Source: https://answers.mindstick.com/blog/267/how-to-implement-send-sms-on-mobile-using-dot-net

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