How can we help?

Common Unsuccessful SMS errors


Common errors in agency settings

Reached maximum numbers of sub accounts:

If you are on trial with Twilio, you can only have one subaccount. Once you upgraded Twilio, the maximum number of subaccounts will be 1000 subaccounts. Closed subaccounts do not count towards this limit.

If your upgraded project is approaching 1000 subaccounts, please contact Twilio Support to ask about raising this limit.

Common Unsuccessful SMS errors in Conversation

For more information about why your SMS was unsuccessful, please click the ⚠️ **(red triangle)** icon  to view more details:

Common errors:

ErrorCode: 11751

Media Message - Media exceeds messaging provider size limit.

The total size of the media message request exceeds the maximum size limit for the channel.

ErrorCode: 30006

The destination number is unable to receive this message. Potential reasons could include trying to reach a landline or, in the case of short codes, an unreachable carrier. 

ErrorCode: 30007

Your message content was flagged as going against carrier guidelines. Your message was filtered (blocked) by Twilio or by the carrier. This may be done by Twilio for violating Twilio’s Messaging Policy or Acceptable Use Policy, or by a wireless carrier for violating carrier rules or regulations.

These are likely filtered due to the URL shortener used in the messages. URL shorteners are prohibited in the US. Once you use your full URL, the SMS will be delivered without issue. 

Carriers actively block messages with shortened URLs to prevent any scamming and also to give the receiver of the message an idea of where the link is taking them prior to clicking on it. 

It does not happen always but the best approach would be to go without the URL shorter to avoid any violation getting reported by Carrier.
To learn the exact reason, you can submit the message examples to Twilio support to check with the phone carrier to troubleshoot further. 

ErrorCode: 30002 / Authenticate
Your account was suspended between the time of message send and delivery. Please contact Twilio. This message failed because your account was suspended after this message was queued but before it was sent by Twilio.

ErrorCode: 30004
The destination number you are trying to reach is blocked from receiving this message.

ErrorCode: 21612
The 'To' phone number: {{contact.number}}, is not currently reachable using the 'From' phone number: +61000000000 via SMS.



You can try to enable geo permission.  However, to guarantee two-way messaging (receiving incoming messages from end-users), you must use a number from the same country as your recipient.

It's best to buy a phone number for the country your contact is in and use that as the default one. And delete the old default Twilio number.

Since the current leads will be stuck with the original Twilio number as explained here:

If you want to keep the original Twilio number, you can assign the phone number to the user, then assign the lead to the user, then you will be able to send from the new number.

Another way is to recreate the contact.