Bulk OTP API

Send OTPs at scale with reliable delivery, idempotent sends, and real-time tracking. Perfect for applications with thousands of daily verifications.

Built for Scale

Our API handles high throughput with wallet-based billing. Top up your wallet and send as many OTPs as you need without per-request payment friction.

Fast Delivery

Multi-provider routing ensures fast delivery even at high volumes. If one provider is slow or overloaded, we automatically route through an alternative.

Track Every Message

Full delivery tracking for every OTP sent. Monitor delivery rates, identify failures, and get complete audit trails via the Messages API.

Idempotent at Scale

Idempotency keys prevent duplicates even during bulk operations. Safe to retry failed requests without worrying about double-sends.

Send an OTP in One API Call

Works with every language. Just a single POST request.

curl -X POST https://api.startmessaging.com/otp/send \
  -H "Content-Type: application/json" \
  -H "X-API-Key: sm_live_your_api_key_here" \
  -d '{
    "phoneNumber": "+919876543210",
    "otp": "123456",
    "idempotencyKey": "unique-request-id-123"
  }'

Bulk OTP FAQ

Send OTPs at Scale

Top up your wallet and start sending. No rate limit negotiations, no contracts.