Marketing
SMS Sender ID: Show Your Brand Name Instead of a Phone Number
An alphanumeric sender ID puts your brand name where a phone number normally appears. It is one-way, it is not available everywhere and it needs an opt-out path. Here is what to check, and how to connect one to your inbox.
MonoChat Team Updated: 4 min read
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Most business SMS arrive from a long number or a short code. In many countries a business can instead send from a name: “ACMESHOP” in the sender line, not +1 555 0100. That name is an alphanumeric sender ID. It builds trust in a one-way alert, but it has rules that catch teams out. This guide covers them, and how to connect a sender ID to MonoChat.
What an alphanumeric sender ID is
Twilio describes it as your company name or brand used as the sender of one-way SMS to supported countries. The format rules from Twilio’s documentation:
- Up to 11 characters.
- English letters in upper or lower case, the digits 0 to 9 and spaces.
- At least one letter: an ID made only of digits is not allowed.
- Some carriers enforce a minimum length, and a non-compliant ID can be changed to a generic sender shown as “unknown”.
What it cannot do
| Limit | What it means for you |
|---|---|
| One-way only | Recipients cannot reply to the message. |
| No automatic STOP | Twilio’s STOP keyword does not opt people out of sender ID messages, so you must offer another opt-out, for example a support contact. |
| Not everywhere | It is not available in the United States or Canada. Sending to an unsupported country fails with an HTTP 400 error, unless a number in your Messaging Service is used instead. |
| Registration in some countries | Some countries accept a sender ID on demand, others need pre-registration with documents before first use. |
| Paid accounts only | Free trial Twilio accounts cannot use it. |
Because customers cannot answer, a sender ID suits order updates, delivery notices, appointment reminders and one-time codes. It does not suit a conversation. If a customer might need to respond, put a contact in the text, or send from a number.
Sender ID, phone number or Messaging Service
- Alphanumeric sender ID: best for one-way alerts in countries that support it; the customer sees your brand.
- Phone number: two-way; customers can reply and your team answers in the inbox.
- Messaging Service: a Twilio sender pool. When you add an alphanumeric sender to the pool, Twilio selects it for supported countries and, for a country without support, uses a phone number from the service. If you have a short code in a country, the short code is used instead.
A common set-up is a Messaging Service with both: the brand name where it works, a number elsewhere, and replies through the number.
How to connect a sender ID in MonoChat
MonoChat’s Twilio SMS channel accepts a phone number, an alphanumeric sender ID or a Messaging Service. In the channel form, pick Sender type:
| Sender type | What to enter | Replies |
|---|---|---|
| Alphanumeric Sender ID | The sender ID (1 to 11 letters and digits, at least one letter), plus Account SID and Auth Token | Not possible |
| Messaging Service | The Messaging Service SID (starts with MG), plus Account SID and Auth Token | Only if you also enter the Phone Number SID of a number in that service |
Steps, in short: create the sender ID or Messaging Service in your Twilio console, register it if the destination country requires it, then add the channel in MonoChat. The full steps are in the help center. SMS fees are billed by Twilio. MonoChat has a free Basic plan at app.monochat.ai; see the pricing page.
Once connected, the SMS channel sits next to your other channels. Use workflow automation to send the notice and tag the customer, and read the rest of the conversation in the shared team inbox. To decide when SMS is the right channel at all, read SMS vs WhatsApp for business, and WhatsApp opt-in for consent.
A checklist before you send
- Confirm the destination country supports sender IDs, and whether it needs pre-registration.
- Choose a short, recognisable name of up to 11 characters.
- Add an opt-out path in the message or on your site, because STOP does not work.
- Decide where replies go: a phone number in a Messaging Service, or a contact line in the text.
- Test with a real handset in each country you serve.
Sources
Put this into practice with MonoChat