Phone, SMS & voice

Alphanumeric sender IDs

Send one-way international SMS from your brand name instead of a phone number, with a daily limit and per-country behaviour.

A sender ID lets your texts arrive from a name such as ACME instead of a number, the way banks and airlines send alerts. There is no number to buy, no monthly fee and no US registration. The trade-off: recipients cannot reply, and sender IDs do not work for the US, Canada or Puerto Rico.

#When to use one

Use a sender ID for Use a phone number for
One-way alerts, codes and notices abroad Two-way conversations
Recipients outside North America Recipients in the US, Canada or Puerto Rico
Text only MMS

#Create the name

POST /v1/sms/sender-ids with a senderId. It is usable at once.

curl -X POST https://api.pozy.ai/v1/sms/sender-ids \
  -H "Authorization: Bearer $POZY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "senderId": "ACME" }'

Rules for the name:

  • 3 to 11 characters: letters, digits and spaces, with at least one letter.
  • It must be your own brand. Names that imitate well-known brands or institutions (banks, payment providers, delivery companies, government bodies) are rejected with 422.
  • Names are not exclusive. Other workspaces can register the same name. Billing and delivery receipts always follow the workspace that sent the message.

DELETE /v1/sms/sender-ids/{id} deactivates a name. Creating the same name again brings it back.

#Send from it

Pass the name as from on the normal send endpoint:

Send
curl -X POST https://api.pozy.ai/v1/sms/messages \
  -H "Authorization: Bearer $POZY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "from": "ACME", "to": "+34612345678", "text": "Your Acme verification code is 482913" }'

Each segment bills at the destination's normal SMS rate. Delivery is reported with message.delivered and message.failed, like any SMS. See Send SMS.

#How countries display it

Behaviour Examples
Shows the name as sent Most of Europe and many other markets
Replaces the name with a number to guarantee delivery Some countries
Requires the name to be registered with local carriers first India and the United Arab Emirates, among others. Contact support@pozy.ai for these.

#Daily limit

Texts sent from sender IDs count against a daily limit that resets at midnight UTC. When it is reached, sends from a sender ID answer 429 until the reset. Texts from your phone numbers are not affected.

GET /v1/sms/sender-ids returns your names. Write to support@pozy.ai to raise your sender ID limit, with what the texts are for, who receives them and roughly how many you send a day. POST /v1/sms/sender-ids/limit-request is not available yet and answers 403 with code: "feature_not_available".

#Limits

Limit Value
Name length 3 to 11 characters
Active names per workspace 1,000
Replies Not possible
MMS Not available
Destinations Not the US, Canada or Puerto Rico

#Errors

Status Code Cause Fix
403 alpha_destination_not_supported to is in the US, Canada or Puerto Rico Send from a phone number
403 mms_not_supported mediaUrls on a sender ID send Remove the media
429 alpha_daily_limit_reached Today's sender ID limit is reached Wait for midnight UTC, or write to support@pozy.ai to raise your sender ID limit
403 sender_id_limit_reached The workspace has 1,000 active names Contact support
422 The name imitates another brand or institution Use your own brand name
402 No payment method on file Add a payment method

#Endpoints

Endpoint What it does
GET /v1/sms/sender-ids List alphanumeric sender IDs
POST /v1/sms/sender-ids Create an alphanumeric sender ID
DELETE /v1/sms/sender-ids/{id} Delete an alphanumeric sender ID
POST /v1/sms/messages Send an SMS/MMS