Sender ID: definition and how it works
Published and updated
The sender ID is what the recipient sees in the from field of a text message: a phone number, a short code, or a registered brand name.
How it works
Every SMS carries an originating address. On a normal phone that is the phone's own number, and the recipient can tap it to reply. When software sends through a carrier route the originator can be set to other things, and each has trade-offs.
A long code is a full-length phone number. Recipients can reply to it and it works in every country, but it carries no brand name. A short code is a five or six digit number leased for high-volume traffic in one country. An alphanumeric sender ID is a string of up to eleven letters and digits, such as a company name. It reads as branded but cannot receive replies, and many countries only allow it after registration: India requires headers registered on the DLT ledger, and several other markets require pre-registration with each operator.
The United States is the notable exception: alphanumeric sender IDs are not supported at all on domestic routes, so businesses send from long codes or short codes.
Two things follow for anyone designing SMS features. The sender ID you can use depends on the destination country, not on your provider. And a sender that cannot receive replies pushes recipients to reply STOP to something else or to ignore the message, so two-way use cases want a real number.
How this applies with textbee
With textbee the sender ID is always the SIM's phone number, in every country. Recipients can call it or reply to it, and replies show up in your account as received messages. Branded alphanumeric senders are a carrier-route feature and are not something a phone can set.
Related terms
- Alphanumeric sender ID: An alphanumeric sender ID replaces the sending phone number with a short text string such as a brand name, up to eleven characters, on routes and in countries that support it.
- Long code: A long code is a standard full-length phone number, such as a ten-digit United States number, used as the sender of SMS.
- Short code: A short code is a five or six digit phone number leased for high-volume application-to-person SMS within a single country.
- Two-way SMS: Two-way SMS is messaging where recipients can reply to the number that texted them and the sender's software receives and acts on those replies.