How to Choose an SMS API in India

• An entity registered as yours

  Commercial SMS is sent by a registered sender. You register your entity on a DLT portal and get an entity ID, which the request carries as dlt_entity_id.

• A header you have been approved

  Commercial SMS may only use registered headers. Your approved header goes in sender_id, and its format is set on your DLT portal.

• A template that matches the text

  The fixed part of each template is hashed, so every message can be checked against it. The template ID goes in dlt_template_id, the text has to match the registered wording, and a template belongs to one header.

• Links only if they are whitelisted

  A URL, APK, OTT link or call-back number that is not whitelisted has not been permitted in SMS since 1 October 2024.

• A declared telemarketer chain

  Since December 2024, a message whose chain is not defined, or does not match the declared one, is rejected. Changing provider is therefore also a change to your registration.

• Tell us what you're building

  Active NotifyTech AI account.

• Get verified

  Verified business profile. Registered Principal Entity (PE) ID. Approved sender ID / header. Approval time: 24-48h.

• Get your keys

  API key & secret key. IP whitelisting (optional). Webhook URL configured.

• Events by webhook, not by polling

  The developer page documents two events, message.delivered and message.failed. It documents no endpoint for polling a message’s status, so store what the webhook tells you.

• A signature on every call

  Each webhook carries an X-NotifyTech-Signature header. The sample checks it against your webhook secret, answers 401 if it does not match, and replies 200 once the event is handled.

• A failed event carries an error

  message.failed includes the message ID and an error field, which the sample logs. Keep both with the message.

• No event means unknown

  If nothing arrives for a message, call it unknown, not failed and not delivered, and decide what your app does next. A status event is not proof that a person read the message.

<?php// webhook.php - Handle delivery reports$payload = file_get_contents('php://input');$data = json_decode($payload, true);$signature =  $_SERVER['HTTP_X_NOTIFYTECH_SIGNATURE'];$secret = 'your_webhook_secret';if (!verifySignature($payload, $signature, $secret)) {    http_response_code(401);    exit('Invalid signature');}switch ($data['event']) {    case 'message.delivered':        updateMessageStatus(          $data['message_id'], 'delivered'        );        break;    case 'message.failed':        updateMessageStatus(          $data['message_id'], 'failed'        );        logError($data['error']);        break;}http_response_code(200);echo json_encode(['status' => 'processed']);

This is the delivery-report sample from the developer page. The secret and the helper functions are placeholders.

Transactional SMS

₹0.25/msg: OTP, order and payment messages

Promotional SMS

₹0.15/msg: bulk marketing campaigns

DLT registration

Fees are set by each access provider; confirm them on your portal

Which product a message uses

Decided when you register the template; confirm with our team