Twilio SMS - Getting Started

Use Twilio to send SMS to your customers as part of your triggered campaigns, either with

Getting started with Twilio

You’ll need a couple of things before you can enable Twilio in

  1. A Twilio account: If you don’t have one, you can sign up on We recommend using a trial account to get started.

  2. A Twilio-specific phone number, shortcode or an alphanumeric id: You can’t use your own phone number to send SMS; you need to purchase a number from Twilio. You can do so from your account page. If you already have a Twilio-specific number, make sure to have it at hand when you’re composing your message later.

    Similarly, if you’re in the US, Canada, or the UK, you can use a short code: a 5- or 6-digit number that can send and receive SMS/MMS. They need to be leased, and Twilio can do so for you; you can read more on Twilio’s documentation page.

    Alternatively, if you have a paid Twilio account with Alphanumeric Sending enabled, you can send using an Alphanumeric ID in instead of a Twilio phone number.

  3. An Account SID and Auth Token: You can see these on your Twilio dashboard:

Twilio credentials

Note: You might also see a set of test credentials for Twilio in your account page. To send SMS with, you’ll need to use the Live credentials, not Test.

Configure your user data in

To make sure that you can reach your customers via SMS, you’ll need to make sure that you have the right data in

Most importantly, you will need to store a phone number for customers (for example, an attribute called phone). Ideally, this number will be formatted in E.164 format. This is very important. If it’s not used, the likelihood that your message will be sent is lower, because Twilio has to try and detect the number format, and that detection may not always be successful.

What is E.164 format?

E.164 is the internationally-standardized format for all phone numbers. If your number is in this format, you can be that much more certain that it will reach your end user. E.164 numbers can have a maximum of fifteen digits and are usually written as follows:

[+][country code][subscriber number including area code]

Here are a few examples:

Country Local E.164
USA 415 555 2671 +14155552671
UK 020 7183 8750 +442071838750
China 021 6309 5246 +862163095246
Australia (08) 9287 8230 +61892878230

More specific information about E.164 (and other phone formats) on Twilio’s support site.

Example user with a phone attribute

Note that the phone number is E.164 formatted!

Customer with phone attribute

Enabling Twilio in

From your workspace dashboard, head to Email & Actions in the left panel, and click ‘Get Started’ next to Twilio:

Twilio configuration - get started

What you’ll need is your Account SID and Authorization Token — as we mentioned, you can get these on your account page in Twilio. Copy and paste them into the fields in, and click Continue Setup:

Twilio configuration - credentials

Syncing Phone Numbers

Once you successfully enable Twilio, you’ll see your synced phone numbers (and short codes, if you’re using them) below your credentials. If you add or change phone numbers in your Twilio account, re-sync here so you can use them in

Using Alphanumeric IDs

You’ll also see Alphanumeric IDs in your Twilio Settings.

These allow you to send one-way messages from a brand name (e.g., CUSTOMERIO) rather than a phone number. A few important things things to keep in mind:

  1. Enable the feature in Twilio first! You can add these in, but if you haven’t enabled it in your Twilio project settings, the message will fail.
  2. They’re one-way: Your customers cannot reply to them.
  3. Opt-in/opt-out: Customers receiving these should have opted in to your service and be informed on how to opt out.
  4. They’re not supported in all countries, including the USA: If you try to send to an unsupported country from an Alphanumeric Sender ID, your SMS will fail to send. Note that some require sender ID pre-registration with Twilio.

Adding an Alphanumeric ID in

Adding one of these is simple: tell us the ID you want to use, and choose a name (how you refer to it internally; your customers won’t see this) and save. You can use both upper- and lower-case ASCII letters, the digits 0 through 9, and space. It can’t be only numbers.

If you need it, Twilio have documentation on how to activate this feature.

Adding Twilio messages to your campaign

Once you have your Twilio enabled, you can start sending SMS messages! First, create a campaign in that will trigger sending an SMS. Here, we’re using an event triggered campaign with invoice_overdue as the trigger. So, once a customer’s invoice is overdue, we want to send them an SMS that lets them know:

Twilio campaign - setting up a trigger

Add your Twilio action to the workflow

Next, add your Twilio SMS to the campaign by clicking the Add workflow item button:

Campaign Setup - Add Workflow Item

And choose Twilio SMS:

Campaign Setup - Add Twilio SMS

Give it a name which makes sense to you— your end-user won’t see this. Then, click Add Twilio SMS. In our case, we’re using “Invoice overdue SMS notification,” in line with our event for this campaign. That way, we know what the SMS does when we see it in our Campaign Overview:

Twilio campaign - naming your SMS

If you want to add an A/B test, now's the time! Just click the "Add A/B test" button, or see more detailed instructions here!

Next, click Add Content to open the SMS composer and set up your message.

Twilio campaign - add content

Compose your Twilio SMS

Finally, it’s time to write your SMS. In the composer, it consists of three parts:

  1. The “From” field: The number, shortcode, or Alphanumeric ID you’re using to send the message
  2. The “To” number: The number that the message is headed to; your user’s number
  3. The message body: This is where your message’s content goes.

Note: You can use Liquid here to send to your customer’s phone number, or to address them personally, if you’d like. Just make sure you have the right attributes for that user. You can see this in action in our example below, or click here to learn more about Liquid in

At this point, your SMS composer should look something like this (you can hit Preview to see what your SMS looks like):

Twilio campaign - writing an SMS to a customer with a phone attribute

If you use Alphanumeric ID here, remember that you must have the feature enabled in your Twilio settings, and users cannot reply to it: it’s one-way only!

Send test request

To make sure your SMS works, you can send a test message by entering a phone number in the test box (shown in the screenshot below), and clicking “Send Test”. This will send a real SMS, so make sure you’re sending the test to yourself (or a test account)!

Once sent, will show you the response from Twilio, and you should see Test sent.

Twilio campaign - send a test SMS


The SMS should then appear on your phone (or whichever number you chose to send it to)! We have a separate guide for tracking your sent Twilio messages.

Twilio campaign - a successful test

Need a hand?

If you have questions, feel free to have a look at the FAQ, or let us know! We’re happy to help.