Introduction

Programmatically making phone calls could sound like it's something reserved for giant telcos only — but with cloud APIs like Twilio, today it's never been simpler. Whether you're creating a notification system, customer support line, or a plain click-to-call feature, Twilio's Voice API makes it possible to configure it in only a few lines of code.

In this guide, you’ll learn how to make an automated phone call using Twilio’s Programmable Voice API with Node.js. We’ll walk through each step of the process, explain the key technologies involved (like TwiML), and share some troubleshooting tips to ensure your call gets through successfully.

To make this as easy to replicate as possible, I've built a step-by-step video guide where I'm walking you through everything discussed on this blog — from getting started with your Twilio account through executing your very first script.

👉If you want to enhance your voice call experience further, you can explore how to create an IVR using Twilio Studio. This tool simplifies building automated voice workflows, perfect for businesses requiring more complex call handling systems.

Watch the Video Tutorial
Want to see the entire process in action? Check out the full walkthrough below where I demonstrate how to make a phone call using Twilio's API in Node.js — from setup to execution.

🎯 What you'll learn in the video:

How to set up your Twilio project
Where to find your Account SID and Auth Token
Writing and running the call script
How TwiML (Twilio Markup Language) works

👉Feel free to watch the video now and follow along with the written steps below!

What is Twilio?

Twilio is a communications platform as a service with APIs to help applications integrate the power of message, voice, and video. It's the go-to technology for developers that helps them implement scalable communication functions without requiring standard telecom infrastructure.

    What are the important features of Twilio?

    • Programmable Voice: Receive and make calls by writing code.
    • Programmable Messaging: Send SMS messages, MMS messages, and WhatsApp messages.
    • Video APIs: Develop live video chat apps.
    • Email APIs (using SendGrid): Send marketing and transactional emails.
    • Authentication: Utilize Verify and Authy for 2FA and secure logins.

    Why Developers Love Twilio:

    • Simple to start with a free trial and well-documented.
    • Functions flawlessly with widely used programming languages such as Node.js, Python, PHP, and others.
    • Pay-as-you-go with international phone number support.

    In this tutorial, we’ll be using Twilio’s Programmable Voice API, which allows us to make a voice call by simply executing a script — no complex PBX setups required.

    Understanding TwiML (Twilio Markup Language)

    Every time Twilio receives or makes a phone call, it has to perform a specific task, whether that’s playing a message, gathering input, recording audio, or redirecting the caller. This is the part where TwiML comes into play.

    What Is TwiML?

    TwiML simply stands for Twilio Markup Language. It is an XML formatted language which conveys to twilio the modus operandi it should adopt for voice call and messages. No advanced logic needs to be programmed — simply send an XML document with straightforward instructions to Twilio.

    👉TwiML (Twilio Markup Language) is essential for controlling call flow. It allows developers to customize actions during a call. For more details, refer to the official Twilio documentation on TwiML.

    🧩 Example of a Basic TwiML Response:

    <?xml version="1.0" encoding="UTF-8"?>
<Response>
  <Say voice="alice">Hello, this is a call from your Twilio-powered app!</Say>
</Response>

    How It Works In This Project:

    • We will give Twilio a URL containing the TwiML XML instructions.
    • When the call connects, twilio will fetch the TwiML from that URL.
    • Twilio will process the Say command and speak it to the person on the other side of the call.

    This is a simple yet powerful way to control call behavior – no hands, no dial out, and no voice prompt commands.

    Requirements Before You Begin

    Before we dive into the code and start making phone calls, there are a few essential things you need to have in place.

      1. A Twilio Account

      To use Twilio’s API, you’ll need a verified account. If you don’t have one yet:

      • Sign up at https://www.twilio.com/try-twilio
      • Verify your email and phone number
      • You’ll receive some free trial credits to test the APIs

      2. A Twilio Phone Number

      Once your account is set up:

      • Go to the Phone Numbers section in the Twilio Console
      • Purchase (or choose) a number with voice capability
      • This number will be used to make the call

      3. Your Twilio Credentials

      Keep these credentials handy from the Console:
      💠Account SID
      💠Auth Token
      You’ll use these in your script to authenticate with the Twilio API.

      4. Node.js Installed

      You’ll need Node.js installed on your system to run the script.
      💠Download from https://nodejs.org/
      💠Verify it’s installed by running:

      node -v
      npm -v

      5. A Public TwiML URL

      For this tutorial, we’ll use a public TwiML Bin (hosted XML file by Twilio):
      ➡️Go to your Twilio Console → TwiML Bins
      ➡️Create a new Bin and paste your XML (e.g., Hello)
      ➡️Save and copy the URL

      Alternatively, if you’re self-hosting, tools like Ngrok can expose your local TwiML file to the internet.

      Female developer reviewing TwiML XML code on desktop screen for Twilio API voice call automation
      A developer using Twilio API and TwiML to automate voice calls, showing code on a desktop screen.

      Step-by-Step Guide to Making a Call Using Twilio API

      In this section, we’ll walk through the exact steps to make a phone call using Twilio API for voice and Node.js. If you’ve followed the video or setup above, you’re all set to dive in.

      1. Set Up Your Project Folder

      First, create a new folder for your project and initialize it as a Node.js app:

      mkdir twilio-call-demo
cd twilio-call-demo
npm init -y

      Then install the Twilio Node.js SDK:

      npm install twilio

      2. Create the Call Script

      Now create a file named makeCall.js and paste the following code:

      const twilio = require('twilio');

// Replace with your Account SID and Auth Token
const accountSid = 'YOUR_ACCOUNT_SID';
const authToken = 'YOUR_AUTH_TOKEN';

const client = twilio(accountSid, authToken);

client.calls
  .create({
    url: 'https://handler.twilio.com/twiml/EHXXXXXXXXXXXXXXXXXXXXXXXXXXXX', // Your TwiML Bin URL
    to: '+1234567890',     // The number you want to call
    from: '+10987654321'   // Your Twilio number
  })
  .then(call => console.log(`Call initiated with SID: ${call.sid}`))
  .catch(error => console.error('Error making call:', error));

      Replace YOUR_ACCOUNT_SID, YOUR_AUTH_TOKEN, and the phone numbers with your actual details. The url should point to your TwiML Bin (created earlier in Twilio Console).

      3. Run the Script

      Once everything is set, run the script using Node.js:

      node makeCall.js

      If everything is set up correctly, you’ll see an output similar to:

      Call initiated with SID: CAxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

      And your phone will ring shortly with the message you wrote in your TwiML!

      Twilio offers a variety of SDKs for developers to integrate different functionalities, such as sending SMS or handling voice calls. Learn how to send SMS using Twilio PHP SDK

      Use Cases for Twilio Voice API

      Programmatically initiating phone calls can be amazingly powerful — particularly when paired with automation or other system data. Here are some actual use cases where Twilio Voice API excels:

      1. Appointment Reminders
      Healthcare professionals, clinics, and spas utilize Twilio to call patients automatically and remind them of their scheduled appointments. The script can even contain dynamic voice prompts with patient names and dates.

      2. Two-Factor Authentication (2FA) through Voice
      In areas where SMS is not reliable or blocked, businesses utilize voice calls to send one-time passcodes (OTP) as an additional security measure.

      3. Order Notifications
      E-commerce companies can make order confirmation calls or delivery notifications. For instance: "Hello John, tomorrow your package will be delivered."

      4. Job Alert or Interview
      HR applications and hiring platforms may employ Twilio to make shortlisted candidates automatic calls with updates or instructions, making them warmer than emails.

      5. Payment Reminders
      Finance institutions and banks leverage automated voice calls to inform customers of impending payments, EMI due dates, or credit card bills.

      6. Marketing Campaigns & Surveys
      Outbound calling is used in marketing campaigns by businesses through Twilio. Combine it with IVR to gain user feedback or conduct a voice survey.

      7. Educational Institutions
      Student notifications, emergency messages, or fee reminders are done by schools and training centers.

      Twilio Voice is versatile enough to grow from an easy demo script like ours to a complete voice automation platform in only a few iterations.

      Final Thoughts

      Using Twilio’s Voice API with Node.js gives you a simple yet powerful way to automate phone calls — perfect for reminders, alerts, notifications, and more. With just a few lines of code, you’ve built the foundation for a scalable voice communication system.
      This blog post walks through the exact steps shown in our YouTube tutorial and explains each part in greater detail — helping both developers and non-tech users understand what’s going on behind the scenes.