If a customer is unable to opt-in to your list, we recommend following the steps below to troubleshoot the issue. If a customer has stopped receiving text messages from your list, and they've received text messages from your list in the past, click here for how we recommend troubleshooting this issue.
1) Double check to make sure the customer is entering the proper SMS keyword and short code into their mobile phone. You'd be surprised how many customers that can't opt-in to a list, and we eventually find out this was the issue.
2) See if there's any record of the customer's mobile phone number in your list, by searching all different subscriber states (subscribed, cleaned & unsubscribed). To perform a search for a customer's mobile phone number within your list, see here. You may find that they are already opted-in to your list, and are successfully subscribed, but for some reason they don't think they are.
3) Check to make sure their wireless carrier is supported by Tatango. You can see a full list of wireless carriers that Tatango supports here. If a customer is using a wireless carrier that is not supported by Tatango, they unfortunately won't be able to opt-in to your list, and even if Tatango imported their phone number into your list, they wouldn't receive any of your messages
4) Test to see if your customer is able to receive short code messages on their mobile phone. These are messages sent to and from 5-6 digit phone numbers. To test, have the customer text the word HELP to another active SMS list. Speak to your Customer Success Manager for a recommendation.
If the customer receives a text message in response from the short code, their mobile phone does support short code messaging. This means this customer's wireless plan does support short code messaging, and most likely means that the customer is not entering the proper SMS keyword and short code into their mobile phone when trying to join your list. If this is not the case, it's best to open a support ticket.
If the customer does not receive a text message in response from the short code, or the response is some type of error, they'll have to call their wireless phone provider, because they don't have short code messaging activated on their wireless plan. When they talk to their wireless phone provider, they'll want to tell them to enable short code text messaging on their wireless plan, as it's currently disable.