Sender IDs

Sender IDs

An alphanumeric sender ID lets your messages arrive from your brand name ("ZERNIO") instead of a phone number, the way banks and airlines text. There is no number to buy, no monthly fee, and no US carrier registration: create a name once, then use it as from when sending.

Quick Reference

Create a sender ID

createSmsSenderId (POST /v1/sms/sender-ids) registers the name. It is usable immediately.

curl -X POST "https://zernio.com/api/v1/sms/sender-ids" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"senderId": "ZERNIO"}'

Names are vetted at creation:

• Names that impersonate well-known brands or institutions (payment providers, delivery carriers, banks, government) are rejected with a 422.
• Active sender IDs are globally unique: a name already registered by another workspace returns a 409 (sender_id_taken), first come, first served.
• A workspace can hold up to 5 active sender IDs (403 sender_id_limit_reached beyond that; contact support to raise it).

List your names with listSmsSenderIds (GET /v1/sms/sender-ids), remove one with deleteSmsSenderId (DELETE /v1/sms/sender-ids/{id}). Deleting deactivates the name; creating it again restores it.

Send from it

Pass the sender ID as from on the regular send endpoint, everything else is unchanged.

const { data } = await zernio.sms.sendSms({
  body: {
    from: 'ZERNIO',
    to: '+34612345678',
    text: 'Your verification code is 482913',
  }
});
console.log(data.id, data.status);

curl -X POST "https://zernio.com/api/v1/sms/messages" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"from": "ZERNIO", "to": "+34612345678", "text": "Your verification code is 482913"}'

Delivery works like any SMS: track it with the message.delivered / message.failed webhooks, and each segment bills at the destination country's SMS rate.

Country behavior

Most of Europe and many other markets display alphanumeric senders as-is. Some countries substitute a numeric sender to guarantee delivery, and a few (for example India and the UAE) require the name to be pre-registered with local carriers before it displays; contact support if you need a registration-required destination.

Daily limits

Each workspace has a daily sender-ID message budget, shared across all its names and reset at midnight UTC:

Hitting the cap returns a 429 (alpha_daily_limit_reached). Request a higher level with requestSmsSenderIdLimitIncrease (POST /v1/sms/sender-ids/limit-request), including your use case and audience, requests are reviewed within a business day, and GET /v1/sms/sender-ids reports your current budget, level, and any pending request.