T-Mobile has a setting that blocks ANY SMS sent to their mobile number from business-type sender numbers, such as Short Codes, Toll-Free, and 10DLC-Routed Long Codes. This includes OTP codes, appointment notifications, etc. from any SMS sender network. This can only be removed by having the recipient contact T-Mobile Support directly to request that setting be turned off. Specifically, the mobile user must call 611 directly from their T-Mobile device experiencing the issue – or if using another device, call 1-800-937-8997 – and request "Toll- Free and Shortcode Blocklist" setting to be removed from their account.
As a result of the above, T-Mobile customers with this setting enabled won't be able to receive NextMe SMS notifications until they turn off the setting. In our experience, this is a very small subset of users. For these T-Mobile customers, they will be impacted when waiting at any business, regardless of whether those businesses are using NextMe or other waitlist platforms / SMS providers. Rest assured, NextMe SMS notifications deliver reliably for all other carriers. Our overall SMS delivery success rate is over 98%.
T-Mobile may change the setting at some point after experiencing a high volume of customer complaints, but it may help to add info on your signage letting your guests with T-Mobile know: There is a known T-Mobile setting that prevents T-Mobile users from receiving business SMS text messages, call 1-800-937-8997 – and request "Toll- Free and Shortcode Blocklist" setting to be removed from your account.