What do the statuses in a delivery report mean?

After every send you get a status per message. Those words look alike but mean something quite different, and the difference decides whether you need to act.

Sent

The message has been sent and is on its way to the recipient. We are still waiting for confirmation that it has arrived.

Delivered

The message has arrived on the recipient’s phone. This is the only status that confirms the SMS got there. Whether anybody read it, nobody knows — SMS has no read receipt.

Buffered

The recipient’s phone is temporarily unreachable, for example because it is switched off or has no signal. The message is kept and sent again as soon as the phone is reachable again. This usually resolves itself.

Expired

The recipient’s phone stayed unreachable for too long. As a result, the message was no longer delivered. For time-critical messages such as codes, keep the validity period short.

Undelivered

The message could not be delivered. Possible reasons:

• This number cannot receive SMS messages (e.g. a data-only SIM card or a SIM card for a device such as an alarm system).
• This number is no longer in use.
• The recipient cannot receive messages at the moment.
• The message was rejected by the recipient’s provider.
• The message could not be delivered to the phone.

If the number no longer exists, remove it from your list.

Rejected

Refused before it travelled: an invalid number, a sender name that is not allowed, or a destination that is not open.

Blacklist

The recipient opted out. Respect that — it is also a legal requirement.

Error

Something went wrong while sending, so the message was not sent. Please try again. If the problem persists, contact us.

Note: messages to numbers in roaming (numbers connected to a network other than their home network) may remain at 'Sent'. We give no delivery guarantee for numbers in roaming; this requires special routes. Contact support.