Every Twilio SMS or MMS message request has a status value which describes the current state of the message. Here are the most common message statuses, and their meanings.
Initial Request Statuses
Queued: For messages where a single phone number is used as the sending party, this status indicates your request was successful and the message is queued to be sent. out.
Accepted: For messages where a messaging service is used as the sending party, this status indicates that Twilio has accepted your request, and will soon determine the optimal 'From' phone number for the message.
Processing Request Status
Sending: Twilio has started the process of dispatching your message request to the nearest upstream carrier.
Sent: The upstream carrier has accepted the message request.
Message Delivery Status
Twilio charges you for the attempt of delivery. This means that if a message has a Status of
delivered, or even
undelivered, you will be charged for the message. On the other hand, if a message is marked as
failed (which in most cases indicates that the upstream provider did not accept the message at all), you will not be charged. For more further assistance, please see our article for Troubleshooting undelivered Twilio SMS messages.
Delivered: Twilio has received confirmation of message delivery from the upstream carrier, (and, where available, the destination handset).
Undelivered: Twilio has received a delivery receipt indicating that the message was not delivered. This can happen for a number of reasons including carrier content filtering, availability of the destination handset, etc.
Failed: The message could not be sent. This can happen for various reasons including queue overflows, account suspensions and media errors (in the case of MMS). Twilio does not charge you for failed messages.
Incoming Message Status
Receiving: An incoming message has been received, and Twilio is processing the message.
Received: An incoming message has been processed, and Twilio has delivered the message to your Twilio number.