---
page_type: error
code: 30018
message: "30018: Destination carrier requires sender ID pre-registration"
level: WARNING
product: Programmable SMS
---

## Description

You sent a message (message SID: SMXXXXX) to a mobile number in a country that requires Alphanumeric Sender ID pre-registration. Our records indicate that you do not have a registered Alphanumeric Sender ID for this country. This can result in lower delivery quality.

If you are sending transactional SMS (like OTP/auth codes, account-related alerts) you should pre-register for the best possible delivery quality.

### Possible Causes

- The recipient you are sending a message to is on a network that requires alphanumeric sender ID pre-registration, and our records indicate that your sender ID is not registered.

### Possible Solutions

- If your message is marked "undelivered," your message was likely rejected by the mobile network and you will need to register an Alpha Sender ID to improve delivery to that network.
- If your message is marked "delivered," it may have been delivered successfully. However, it is still strongly recommended to register an Alpha Sender ID for the destination country if possible.
- Learn more about Alpha Sender ID registration requirements [here](https://support.twilio.com/hc/en-us/articles/223133767-International-support-for-Alphanumeric-Sender-ID).
- Use [this form](https://twiliodoer.secure.force.com/SenderId) to register a Sender ID for the destination country.
- If you are sending OTP/2FA codes consider using [Twilio Verify or Authy](https://www.twilio.com/en-us/trusted-activation/verify) which will automatically take care of all applicable registrations.