Rate this page:

Narrowband: The Twilio SIM for Massive IoT

Currently, only the T-Mobile NB-IoT network in the United States is supported.

Twilio’s Narrowband SIM is presented in partnership with T-Mobile USA and enables access to the T-Mobile Narrowband (NB-IoT) network.

Narrowband technology enables high volume, low bandwidth, and data-only Internet of Things (IoT) use cases. These ‘Massive IoT’ applications involve huge numbers of low-complexity devices that send or receive messages infrequently. Typical use cases include low-cost sensors, preventative maintenance monitors, utilities meters, and location trackers. Devices like these are often deployed in challenging radio conditions, such as in building basements or outdoors at the extremes of network tower coverage. They often rely solely on battery power and may need to stay operational for years between maintenance checks.

Narrowband was designed specifically to improve the power consumption of devices that send small or infrequent packets of data. Its technical fundamentals reduce the cost of connectivity and lower the cost of hardware.

In order to connect a Twilio Narrowband SIM to the T-Mobile Narrowband IoT network, a T-Mobile pre-certified module is required, such as the Quectel BC66 NB-IoT. Please check if you have a T-Mobile certified and allowed module here.

Get Started with Massive IoT

Twilio’s Narrowband SIM operates much like the Programmable Wireless SIM — you use the Programmable Wireless API to manage Narrowband SIMs, for example — but there are a number of small differences that you should be aware of if you have used other Twilio IoT SIMs before.


Narrowband SIM is a data-only service.


You can order Narrowband SIMs from the Console. You can order a three-SIM Starter Pack or bulk-order Narrowband SIMs (minimum order size ten SIMs). Starter Pack SIMs need to be registered with your Twilio account through the Console. Please see this article if you need help. Bulk-ordered SIMs will be linked to your account automatically.

Twilio Narrowband SIMs use the the same set of SIM states as Programmable Wireless SIMs.

After you’ve received and registered your SIMs, you need to assign them to a Rate Plan.

Data Metering Plans

Narrowband SIMs require a specific Data Metering Plan. There are two Data Metering Plans available for Narrowband SIMs.

The Developer Plan is designed for prototyping. Choose this plan if you are starting out building your device. The Developer Plan costs $2 per month and includes 2MB of data per month. Overages cost 10¢ per 100 KB increments.

The Annual Plan is designed for production deployments. Most NB-IoT deployments have devices that have long lifetimes of many years, which makes the annual plan more suitable than the Developer Plan for such deployments. The Annual Plan charge includes 12MB of data that can be consumed within the year. Any overages will cost 10¢ per 100 KB increments.

The Data Metering Plan is selected during the creation of a Rate Plan. To create a Plan, follow these steps:

Visit the Create a Rate Plan section of the Console

  1. Select Narrowband for SIM type.
  2. Continue through the Rate Plan creation process, selecting one of the above Data Metering Plans when requested.

The SIM is ready to use after it has been assigned to the Rate Plan and it has been activated.


If you prefer to work through the setup process in a more structured way, we have a full Narrowband IoT getting started guide here. It is based on the Twilio Developer Kit for Narrowband IoT.

The Breakout SDK for Massive IoT

Twilio provides a free SDK, called Breakout, to abstract away some of the more complex elements of narrowband-based Massive IoT deployment, such as cellular modem hardware and cellular network registration. The Breakout SDK allows developers to exchange data between low-powered narrowband devices and their cloud-based services.

To learn how to incorporate the Breakout SDK into your IoT application, please see this tutorial.

Device certification for production

Any product utilizing the T-Mobile NB-IoT network that is intended for commercialization will need to be certified by T-Mobile. To learn more about certification requirements for your Narrowband device, please see this page.

Device power optimization

Narrowband incorporates a number of technical innovations to reduce device power consumption. If you’d like to learn more about these Narrowband features and how they might enhance the operation of your IoT product, please see this guide.

Rate this page:

Need some help?

We all do sometimes; code is hard. Get help now from our support team, or lean on the wisdom of the crowd by visiting Twilio's Community Forums or browsing the Twilio tag on Stack Overflow.

Thank you for your feedback!

We are always striving to improve our documentation quality, and your feedback is valuable to us. How could this documentation serve you better?

Sending your feedback...
🎉 Thank you for your feedback!
Something went wrong. Please try again.

Thanks for your feedback!

Refer us and get $10 in 3 simple steps!

Step 1

Get link

Get a free personal referral link here

Step 2

Give $10

Your user signs up and upgrade using link

Step 3

Get $10

1,250 free SMSes
OR 1,000 free voice mins
OR 12,000 chats
OR more