How do you integrate an SMS API?

First, find and sign up for an SMS API provider like Twilio Get an API key from your provider Purchase a phone number to send the messages from Decide what type of messages you want to send and how you want to send them Write code to connect to the API and send your messages Test your code to verify that your messages are going through The amount of time it takes to integrate an SMS API depends on the complexity of your project and your experience with similar integrations. Get started with our Programmable SMS quickstart See the Programmable Messaging API overview

What are the different types of phone numbers for business texting?

When you set up your SMS API, you have to set up a phone number to send your messages from. Here are your options for business messaging: Toll-free numbers Toll-free numbers are 10-digit numbers that have a standard prefix like 800 or 833 (1-833-456-78XX). Can be used for calls and text messages Support high-throughput for high-volume use cases like notifications, alerts, and promotions Require a verification process for high-volume use cases See more about toll-free numbers A2P 10DLC Application-to-person 10-digit long codes are numbers with a local prefix, like +1 (415) 568-00XX. Specifically for business messaging traffic Support both phone calls and text messages A verification process is required to prove you are a trusted sender with approved campaigns See more about 10DLC numbers Short codes Short codes are 5-6 character codes (56748) that are recognizable, and can be used for text and picture messaging. Throughput starts at 100 messages per second Support high-volume use cases like alerts, notifications, verifications, and promotions A verification process is required to prove you are a trusted sender with approved campaigns See more about short codes

SMS

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Twilio positioned as a Leader in the 2025 Gartner® Magic Quadrant™ for CPaaS*

Read the 2025 report

Build once. Message everywhere.

Launch fast, scale globally, and deliver reliably. Twilio SMS combines developer-first APIs with built-in compliance and carrier routing to get the right message to the right person at the right moment (every time).

From first text to global scale with Twilio SMS APIs

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Programmable Messaging API

Send transactional MMS, SMS, and
WhatsApp messages with a single API.

Reach 180+ countries reliably with localized senders, compliance tools, and global guidelines.
Manage compliance, deliverability, replies, and more with Twilio’s programmable software.
Monitor and troubleshoot message delivery and engagement with real-time analytics.

Explore the Programmable Messaging API

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Conversations API

Drive two-way engagement with cross-channel messaging for MMS and more using a single API.

Power commerce and support on SMS, MMS, chat, Facebook Messenger, and WhatsApp.
Manage participants, archive messages, and orchestrate workflows without additional code.
Get to market faster with quick-starts, sample apps, and SDKs.

Explore the Conversations API

Lasting customer relationships start with SMS

Notifications

Keep customers in the know. Send alerts, reminders, and updates that land on time, every time—appointments, deliveries, and everything in between.

Learn about notifications

Verifications

Let good users in, keep the bad actors out. Deliver secure one-time passwords instantly for sign-ups, logins, and transactions.

Learn about verifications

Promotions

Turn messages into momentum. Send marketing campaigns and offers at scale to drive leads, boost sales, and build loyalty.

Learn about promotions

Conversational care and commerce

Talk with customers (not at them). Support the full customer journey with two-way SMS, WhatsApp, and more from a single API.

Learn about conversations

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The ROI of Twilio Messaging

The Total Economic Impact™ of Twilio Messaging

A commissioned study conducted by Forrester Consulting found Twilio Messaging provided:

132% ROI for customers
3% increase in messages delivered
15% productivity improvement in development teams

View the study

Sending 2FA or OTP? Increase conversion rates with Verify

Verify is a purpose-built authentication solution for 2FA, OTP, Passkeys, Silent Network Authentication and more.

Get more users verified with Verify

Verify is a fully managed, multichannel authentication solution that’s optimized for redundancy, low-latency, and global scale.

Robust security measures built in
Meet global compliance and regulatory standards
100% guaranteed protection from SMS pumping fraud with Twilio Verify Fraud Guard*
Deliver via SMS or WhatsApp, voice, TOTP, Push, Passkeys, and more

Learn more about Verify

Intuit was using SMS to deliver one-time passcodes until they tried Twilio Verify. Now, they have a verification solution with high deliverability, global compliance, built-in redundancy, and more—and it was implemented in record time.

94%

deliverability of verification messages

1M+

SMS sent worldwide

Read the story

* Terms and conditions apply

Check out the docs

Kickstart your build for SMS text messaging using our quick-start guides, code snippets, SDKs, and more in our resource library.

Read SMS docs

Create a message

      

			// Download the helper library from https://www.twilio.com/docs/node/install
const twilio = require("twilio"); // Or, for ESM: import twilio from "twilio";

// Find your Account SID and Auth Token at twilio.com/console
// and set the environment variables. See http://twil.io/secure
const accountSid = process.env.TWILIO_ACCOUNT_SID;
const authToken = process.env.TWILIO_AUTH_TOKEN;
const client = twilio(accountSid, authToken);

async function createMessage() {
  const message = await client.messages.create({
    body: "This is the ship that made the Kessel Run in fourteen parsecs?",
    from: "+15017122661",
    to: "+15558675310",
  });
  
console.log(message.body);
}

createMessage();
		


      

			# Download the helper library from https://www.twilio.com/docs/python/install
import os
from twilio.rest import Client


# Find your Account SID and Auth Token at twilio.com/console
# and set the environment variables. See http://twil.io/secure
account_sid = os.environ['TWILIO_ACCOUNT_SID']
auth_token = os.environ['TWILIO_AUTH_TOKEN']
client = Client(account_sid, auth_token)

message = client.messages.create(
                              from_='+15017122661',
                              body='Hi there',
                              to='+15558675310'
                          )

print(message.sid)
		


      

			// Install the C# / .NET helper library from twilio.com/docs/csharp/install

using System;
using Twilio;
using Twilio.Rest.Api.V2010.Account;


class Program
{
    static void Main(string[] args)
    {
        // Find your Account SID and Auth Token at twilio.com/console
        // and set the environment variables. See http://twil.io/secure
        string accountSid = Environment.GetEnvironmentVariable("TWILIO_ACCOUNT_SID");
        string authToken = Environment.GetEnvironmentVariable("TWILIO_AUTH_TOKEN");

        TwilioClient.Init(accountSid, authToken);

        var message = MessageResource.Create(
            from: new Twilio.Types.PhoneNumber("+15017122661"),
            body: "Hi there",
            to: new Twilio.Types.PhoneNumber("+15558675310")
        );

        Console.WriteLine(message.Sid);
    }
}
		


      

			// Install the Java helper library from twilio.com/docs/java/install

import com.twilio.Twilio;
import com.twilio.rest.api.v2010.account.Message;
import com.twilio.type.PhoneNumber;

public class Example {
    // Find your Account SID and Auth Token at twilio.com/console
    // and set the environment variables. See http://twil.io/secure
    public static final String ACCOUNT_SID = System.getenv("TWILIO_ACCOUNT_SID");
    public static final String AUTH_TOKEN = System.getenv("TWILIO_AUTH_TOKEN");

    public static void main(String[] args) {
        Twilio.init(ACCOUNT_SID, AUTH_TOKEN);
        Message message = Message.creator(
                new com.twilio.type.PhoneNumber("+15558675310"),
                new com.twilio.type.PhoneNumber("+15017122661"),
                "Hi there")
            .create();

        System.out.println(message.getSid());
    }
}
		


      

			require_once '/path/to/vendor/autoload.php';

use Twilio\Rest\Client;

// Find your Account SID and Auth Token at twilio.com/console
// and set the environment variables. See http://twil.io/secure
$sid = getenv("TWILIO_ACCOUNT_SID");
$token = getenv("TWILIO_AUTH_TOKEN");
$twilio = new Client($sid, $token);

$message = $twilio->messages
                  ->create("+15558675310", // to
                           ["from" => "+15017122661", "body" => "Hi there"]
                  );

print($message->sid);
		


      

			# Download the helper library from https://www.twilio.com/docs/ruby/install
require 'rubygems'
require 'twilio-ruby'

# Find your Account SID and Auth Token at twilio.com/console
# and set the environment variables. See http://twil.io/secure
account_sid = ENV['TWILIO_ACCOUNT_SID']
auth_token = ENV['TWILIO_AUTH_TOKEN']
@client = Twilio::REST::Client.new(account_sid, auth_token)

message = @client.messages.create(
                             from: '+15017122661',
                             body: 'Hi there',
                             to: '+15558675310'
                           )

puts message.sid
		


      

			# Install the twilio-cli from https://twil.io/cli

twilio api:core:messages:create \\
    --from +15017122661 \\
    --body "Hi there" \\
    --to +15558675310
		


      

			curl -X POST "https://api.twilio.com/2010-04-01/Accounts/\$TWILIO_ACCOUNT_SID/Messages.json" \\
--data-urlencode "From=+15017122661" \\
--data-urlencode "Body=Hi there" \\
--data-urlencode "To=+15558675310" \\
-u \$TWILIO_ACCOUNT_SID:\$TWILIO_AUTH_TOKEN
		

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SMS messaging FAQs

An SMS API is an application program interface that lets you send SMS text messages through an SMS gateway.

SMS APIs 'bridge the gap' between telecommunications carrier networks and the internet so you can easily send and receive text messages from web applications.

SMS API full definition

Bulk SMS messaging is when you send SMS to large lists of recipients. To send bulk SMS, you need:

1. An SMS service provider that can deliver your messages for you

For large-scale messaging use cases, it’s important to find an SMS service that can deliver messages reliable at any volume.

2. The right kind of phone number to send messages en masse

Application-to-person 10-digit long codes (A2P 10DLC) are verified numbers specifically made for businesses to send messages to customers. Short codes (5- or 6-digit numbers) that are approved by carriers are another option for high-throughput messages. Toll-free numbers (10-digit numbers like 833-569-67XX) are another option for high throughput.

3. The right message

Create messages that are meaningful and valuable to your recipients. If you fail to do this, recipients will ignore your messages or block your number. We recommend personalizing messages as much as possible.

4. Opt-ins

To send to any recipients, you need to build a list of people who have expressly opted in to your messages.

For more information, read SMS Bulk Messaging 101

SMS marketing is sending marketing messages directly to customers’ phones via SMS or text message. Sometimes you might hear SMS marketing referred to as text message marketing.

SMS marketing covers any kind of promotion message, including discount offers, product announcements, personalized offers, abandoned cart announcements, and more. If you can get customers to opt in to SMS marketing messages, you can benefit from high open rates, high response rates, and fast delivery straight to customers.

SMS marketing for beginners

How to champion SMS marketing to your stakeholders

First, find and sign up for an SMS API provider like Twilio
Get an API key from your provider
Purchase a phone number to send the messages from
Decide what type of messages you want to send and how you want to send them
Write code to connect to the API and send your messages
Test your code to verify that your messages are going through

The amount of time it takes to integrate an SMS API depends on the complexity of your project and your experience with similar integrations.

Get started with our Programmable SMS quickstart

See the Programmable Messaging API overview

An SMS API makes it easy to send and receive SMS and MMS messages from a web application via an HTTP request.

SMS APIs act as a connection between your app to the telecommunications carrier networks so you can send and receive text messages to recipients. They also convert the message to a format that can be sent over the carrier network/that the web application can understand when someone responds.

How to use Twilio’s REST APIs

An SMS gateway is a service that makes it possible to send and receive SMS text messages through a REST API (like an SMS API). This is the “bridge” between the code you write in your web application and the global telecommunications network that delivers it to a recipient’s mobile phone.

The SMS gateway is also what translates the message so it’s compatible with the carrier network.

They usually route SMS text messages to the telco networks via an SMPP interface that networks expose, either directly or via an aggregator that sells messages to multiple networks.

See more information on SMS gateways

When you set up your SMS API, you have to set up a phone number to send your messages from. Here are your options for business messaging:

Toll-free numbers

Toll-free numbers are 10-digit numbers that have a standard prefix like 800 or 833 (1-833-456-78XX).

Can be used for calls and text messages
Support high-throughput for high-volume use cases like notifications, alerts, and promotions
Require a verification process for high-volume use cases

See more about toll-free numbers

A2P 10DLC

Application-to-person 10-digit long codes are numbers with a local prefix, like +1 (415) 568-00XX.

Specifically for business messaging traffic
Support both phone calls and text messages
A verification process is required to prove you are a trusted sender with approved campaigns

See more about 10DLC numbers

Short codes

Short codes are 5-6 character codes (56748) that are recognizable, and can be used for text and picture messaging.

Throughput starts at 100 messages per second
Support high-volume use cases like alerts, notifications, verifications, and promotions
A verification process is required to prove you are a trusted sender with approved campaigns

See more about short codes

Introducing Twilio Messaging Engagement Suite

Get simpler development, quicker time to market, and higher deliverability rates.** See how Message Scheduling, Link Shortening with Click Tracking, advanced data, and real-time dashboards can benefit your business.

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* Gartner®, Magic Quadrant™ for Communications Platform as a Service, Lisa Unden-Farboud, Manoj Bhatia, Pankil Sheth, Ajit Patankar, July 21, 2025

** In an evaluation of more than 63M messages sent through Twilio with shortened hyperlinks, messages with shortened hyperlinks by 3rd party Link Shorteners were filtered at 1.96% or 28x the rate of Twilio which was filtered at a rate of 0.07%