Glossary
What is Alphanumeric sender ID?
An alphanumeric sender ID is a business name of up to 11 letters and digits that appears in place of a phone number as the sender of a text.
The 11-character cap comes from the SMS format, and spaces count towards it. A name suits one-way texts where it matters more that people know who's texting than that they can answer: delivery slots, appointment reminders, offers. The catch is that nobody can reply to a name. A 'Reply STOP' line won't work on a text sent from one, so a marketing text from a name needs to tell people another way to opt out, such as an email address.
A kitchen fitter in Norwich could text as 'NorwichKit' (10 characters) for appointment slots and send quotes from a number, so customers can come back with questions.
CaptiFi Connect accepts names of 3 to 11 characters made of letters, digits, spaces and . & _ -, with at least one letter. Staff check each request against the MEF SenderID Protection Registry and refuse names that imitate another brand or a public body. Once a name is approved you can pick it on the Send SMS page and in campaigns, or pass it in the API's sender field. The opt-out line on campaigns is editable in Settings, which is where you'd change it for texts sent from a name.