Alphanumeric sender ID
What is Alphanumeric sender ID?
An alphanumeric sender ID is a text name — such as “ORBIT” or a brand name, up to 11 characters in most countries — that appears as the message source instead of a phone number, used widely outside the US and Canada for one-way SMS notifications and marketing. Because it can't receive replies, an alphanumeric sender ID suits alerts and OTPs but not two-way conversations, and most countries that allow it require the name to be pre-registered before sending.
More detail
Alphanumeric sender IDs are not supported for A2P traffic in the US or Canada, where a registered 10DLC long code or short code is used instead.
Because replies can't route back to an alphanumeric name, any flow that needs a two-way conversation — support, OTP-and-reply — needs a numeric sender ID (a long code or short code) instead.
Frequently asked
- Can customers reply to an alphanumeric sender ID?
- No. Because there's no underlying phone number, replies have nowhere to route, which is why alphanumeric sender IDs suit one-way alerts and marketing but not two-way conversations.
- Can I use an alphanumeric sender ID in the US?
- No. The US and Canada require A2P traffic to go through a registered 10DLC long code or short code instead; alphanumeric sender IDs are used in many other countries where local carrier rules permit them.
See also
Build it on Orbit
Voice, messaging, email, video, and AI agents on one platform and one pay-as-you-go bill. Start free — no credit card required.