Sender ID

• Alphanumeric — letters and digits, up to 11 characters (spaces count in many systems). One-way only.
• Numeric long number — a regular phone number in E.164 format; supports replies.
• Short code — a 5–6 digit short code, national and pre-approved.

The sender value is set by the business through its SMS provider. The receiving network decides whether to show it as sent, replace it with a generic number, or block the message.

Regulation varies widely, and changes over time:

• Not supported in some markets — the US and Canada do not support alphanumeric sender IDs for standard A2P traffic, so senders use short codes, toll-free or registered long numbers.
• Registration required in many countries (for example, India requires registered headers and templates; the UK, Singapore and others have sender ID registries aimed at reducing impersonation).
• Freely allowed in others, subject to operator filtering.

Always check the current rules of the destination country and your SMS provider's documentation.

Many OTP messages arrive under the service's brand name, which is why codes on the same phone can come from "Google" in one country and a short code in another. For users, the important point is that a familiar sender name is not proof of authenticity in countries without registration — spoofed names can make a phishing text appear in the same thread as genuine messages. Treat links and code requests with caution regardless of the displayed sender.

Receiving alphanumeric senders depends on carrier routing, which is one reason delivery can differ between number types. PhoneBorn numbers show incoming texts with the sender as delivered by the network, in the browser SMS inbox. PhoneBorn itself does not allow custom sender IDs or bulk messaging — see the acceptable use policy.