
Last Update: January 2024
A high error rate can be driven by one error code or by the sum of several collectively. This usually means that carriers are flagging your messages because of the verbiage, Landline or unreachable carrier or Unknown destination handset. (see the Error and Warning Dictionary for a full list of all possible Twilio REST API error codes).
A high opt-out rate is an indication of unwanted/unsolicited messaging.
Your targeted audience must be aware of what they are signing up for and your website/form must clearly state how their information will be used and they have to provide consent to it accordingly. For example, you can't obtain the consent of message recipients by purchasing a phone list from another party.
Prior to sending the first message, you must obtain agreement from the message recipient to communicate with them - this is referred to as "consent", you must make clear to the individual they are agreeing to receive messages of the type you're going to send. You need to keep a record of the consent, such as a copy of the document or form that the message recipient signed, or a timestamp of when the customer completed a sign-up flow. Consent can't be bought, sold, or exchanged. For example, you can't obtain the consent of message recipients by purchasing a phone list from another party.
Every message you send must clearly identify you (the party that obtained the opt-in from the recipient) as the sender, except in follow-up messages of an ongoing conversation. Such that the message recipient can immediately associate where/whom they have given consent to.
The initial message that you send to an individual needs to include the following language: "Reply STOP to unsubscribe," or the equivalent using another standard opt-out keyword, such as STOPALL, UNSUBSCRIBE, CANCEL, END, and QUIT.