Getting a phone number

Before you can get a phone number and send SMS messages, you’ll need to register as a sender, which includes several steps—including making sure that your privacy policy and terms and conditions are updated to reflect your SMS-use case.

Providers require the following things; you must be compliant before you register for a phone number. It can take 1-2 weeks for carriers to review and approve or deny your request, and starting with these ready helps you avoid delays and get approved to send SMS faster. If Customer.io manages SMS for your account, we’ll help you register as a sender—get these ready before you contact us, and we’ll submit your registration.

Update your privacy policy Update your terms and conditions Provide clear opt-in and opt-out instructions Write example messages representing your campaigns Contact Customer.io to register as an SMS sender

Can Customer.io manage your SMS provider for you?

If you’re based in the US or Canada and only send messages to people in the US or Canada, we can provision and manage your sender phone numbers, walk you through carrier registration, and bill you for your messages directly—so you don’t have to manage your own SMS provider. To get started, contact your customer success manager (CSM), or win@customer.io if you don’t have a customer success manager.

You’re eligible for Customer.io to manage SMS for you if:

Your business is based in the US or Canada.
You only send messages to people in the US or Canada.
You don’t require advanced analytics like revenue attribution or sending queues.

If you don’t meet this criteria, you can still send SMS through Customer.io—you’ll connect your own provider account and manage your phone numbers there.

flowchart LR B{Is your business based in the US or Canada?} B -.->|No| C[Connect your own SMS provider account] B -->|Yes| D{Do you send messages to people outside the US or Canada?} D -.->|Yes| C D -->|No| E{Do you need analytics like revenue attribution or sending queues?} E -.->|Yes| C E -->|No| G[You're eligible for Customer.io native SMS! Contact your CSM] style G fill:#e1f5fe,stroke:#01579b,stroke-width:2px style C fill:#fff3e0,stroke:#e65100,stroke-width:2px

How long will it take for me to be approved?

When you request a phone number and register as a sender, cellular carriers review your registration. This can take a while; we typically see approval responses in 1-2 weeks—though it can take longer if carriers request changes to your privacy policy and terms and conditions.

As regulatory requirements change and penalties for non-compliance increase, carriers have become more strict in their approval process. Following the guidance in this section can help you avoid delays and get your number approved faster. More importantly: it’ll help you avoid penalties for non-compliance.

Updated September 15, 2026