When sending messages to India, your Twilio phone number will not appear as the sender of the message. This is common when sending SMS across international borders. In the case of India, the sender ID will be changed by the carrier before your SMS messages are delivered to end users. Instead of your Twilio number, end users will see a random short number between 5 and 9 digits long, e.g. 5NNNN - 5NNNNNNN.
Messages from Twilio will not be affected by India's national "Do Not Disturb" (DND) list for SMS.
Due to the sender ID change, recipients are unable to send a reply back to your Twilio phone number; SMS messaging to India is 1-way (outbound) only.
If you are interested in conducting two-way messaging with mobile users in India, you may be interested in the Twilio API for WhatsApp. Please note that currently "Authentication/OTP" use cases are not supported via WhatsApp to India due to a Meta limitation.
For more information about two-way SMS support on Twilio, see Receiving Two-Way SMS and MMS Messages with Twilio.
For details about SMS messaging to India, see Twilio’s SMS Guidelines page for India.