---
page_type: error
code: 21608
message: "21608: The 'to' phone number provided is not yet verified for this account."
level: ERROR
---

## Error - 21608

### This number can send messages only to verified numbers

You have attempted to send a message to an unverified phone number while using a trial account.

To prevent spam, trial accounts can only send messages to phone numbers you've verified with Twilio. You must upgrade your account to remove this restriction.

### Possible solutions

- Verify the phone number you wish to reach via the [Twilio console](https://www.twilio.com/console/phone-numbers/verified). See step-by-step instructions in our [guide to working with your trial account](/docs/usage/tutorials/how-to-use-your-free-trial-account#verify-your-personal-phone-number). _Note that you will need access to this device to receive the call or text with your verification code._
- Upgrade your Twilio trial account to a full paid account to remove this restriction by providing your payment information via credit card or Paypal on the [console billing page](https://www.twilio.com/console/billing).