India
Name

India

ISO Code

IN

Region

Asia

Mobile Country Code

404, 405

Dialing code

+91

Major carriers

Airtel, Vodafone India, Idea Cellular, Reliance Jio, BSNL, Aircel, Reliance Communication

Guidelines for India
Two-way SMS supported

Two-way A2P SMS over long code is not allowed. This is only allowed over short code starting with a 5 as the header. Twilio does not support 2-way SMS over India short code today.

Number portability available

Yes

Twilio concatenated message support

Yes

Twilio MMS support

Converted to SMS with embedded URL

Sending SMS to landline numbers

You cannot send SMS to a landline destination number: the Twilio REST API will throw a 400 response with error code 21614, the message will not appear in the logs, and the account will not be charged.

Best practices

Twilio fully supports all types of traffic to India, including promotional, ILDO, and transactional content. You must submit promotional or marketing messages between 09:00 and 21:00 local time; anything submitted outside this time will be processed the next day. Sender IDs will be overwritten with a 6-digit short code (XX-NNNNNN), and messages sent to numbers registered in the do-not-disturb database will be blocked. See here for more info - https://support.twilio.com/hc/en-us/articles/223134167-Limitations-sending-SMS-messages-to-Indian-mobile-devices

You should send transactional content like alerts, banking, and OTPs through a carrier-approved transactional connection. To bypass the do-not-disturb database and submit messages at any time of the day, you must register a 6-character, no special characters, all-capitalized alphanumeric Sender ID.

You must submit over-the-top (OTT) traffic originating outside India through a dedicated connection and not through conventional promotional or transactional connections. OTT messages need to go through mobile carriers' International Long Distance Operator (ILDO) connections and have to be terminated with either a short code or a long number. Mobile carriers are actively blocking OTT messages submitted through non-authorized connections.

Twilio strongly encourages customers to review proposed use cases with qualified legal counsel to make sure that they comply with all applicable laws. The following are some general best practices:

  1. Get opt-in consent from each end user before sending any communication to them, particular for marketing or other non-essential communications.
  2. Only communicate during an end user's daytime hours unless it is urgent.
  3. SMS campaigns should support HELP/STOP messages, and similar messages, in the end user's local language.
  4. Do not contact end users on do-not-call or do-not-disturb registries.
Phone Numbers and Sender ID
Preregistered
Operator network capability

Supported

Twilio supported

Supported

Sender ID format

Alphanumeric

Sender ID preserved

Supported

Two-way support

Not supported

Provisioning time

1 week

Cost
--
Throughput (messages per second)

10 messages/second

Use case restrictions

Only transactional messages: 2-factor authentication codes, pin codes, delivery notifications, etc. No marketing messages

Best practices

By default, Twilio sends messages to India as promotional messages. If you are sending transactional content, we highly recommend you register your Sender ID. Sending transactional traffic with a registered Sender ID bypasses the DND database and time restriction. Create a subaccount and split out your transactional SMS traffic to ensure you are compliant.

Alphanumeric
Operator network capability

Preregistered only

Twilio supported

Preregistered only

Sender ID format

Alphanumeric

Sender ID preserved

Yes. Due to regulations, Sender IDs will be prefixed with an India 2-letter prefix source (YZ-ABCDEF) where Y connotates the service provider sending the SMS and Z connotates the telecom circle that the SMS was sent from.

Two-way support

Not Supported

Provisioning time
--
Cost
--
Throughput (messages per second)
--
Use case restrictions

Must be used for transactional content (alerts, banking, OTPs)

Best practices

By default, Twilio sends messages to India as promotional messages. If you are sending transactional content, we highly recommend you register your Sender ID. Sending transactional traffic with a registered Sender ID bypasses the DND database and time restriction. Create a subaccount and split out your transactional SMS traffic to ensure you are compliant.

Long Code
Operator network capability

Not supported

Twilio supported

Not supported

Sender ID format
--
Sender ID preserved

Not supported

Two-way support

Not supported

Provisioning time
--
Cost
--
Throughput (messages per second)
--
Use case restrictions
--
Best practices
--
Short Code
Operator network capability
--
Twilio supported

Not supported

Sender ID format
--
Sender ID preserved

Not supported

Two-way support

Not supported

Provisioning time
--
Cost
--
Throughput (messages per second)
--
Use case restrictions
--
Best practices
--
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