A2P SMS regulations in India.
Compliance with TRAI and DLT.
A2P SMS in India is governed by TRAI (the Telecom Regulatory Authority of India) under the TCCCPR 2018 (Telecom Commercial Communications Customer Preference Regulations). Every commercial sender must complete DLT (Distributed Ledger Technology) registration — Principal Entity, Header (sender ID), and Content Template — on the operator DLT portals before any message will deliver. Traffic is category-scoped (Promotional, Transactional, Service), promotional SMS is limited to 10am–9pm, and subscriber preferences are honoured through the DND registry.
Who regulates A2P SMS in India?
A2P messaging in India is regulated by the Telecom Regulatory Authority of India (TRAI). The binding instrument is the Telecom Commercial Communications Customer Preference Regulations, 2018 (TCCCPR 2018), which moved the entire commercial-messaging ecosystem onto a blockchain-based DLT (Distributed Ledger Technology) framework operated jointly by the access providers. Enforcement is implemented at network level by the operators — Jio, Airtel, Vi and BSNL.
- Regulator: TRAI (trai.gov.in).
- Core rulebook: TCCCPR 2018.
- DLT framework is run by the operators (Jio, Airtel, Vi, BSNL).
DLT registration: Principal Entity, Header and Template
Before sending, every business ("Principal Entity") must register on an operator DLT portal, then register each Header (sender ID) and each Content Template it intends to use. Headers are six alphanumeric characters and are scoped to a category — Promotional, Transactional or Service — so a header registered for one category cannot be used for another. Message content must match a pre-approved Content Template; free-text that deviates from the template is scrubbed (blocked).
- Register the Principal Entity once on a DLT portal (Jio/Airtel/Vi/BSNL).
- Register each Header (6-char alphanumeric sender ID), category-scoped.
- Register Content Templates; content must match an approved template.
- Consent Templates capture and evidence subscriber opt-in.
- Registration on one operator's DLT propagates across the ecosystem.
Promotional, transactional and service categories
TCCCPR classifies traffic so the right rules apply. Promotional messages are purely marketing and require the recipient not to be on the DND (Do Not Disturb) list; they can only go out in the permitted window. Transactional messages are tied to an OTP or a completed transaction with the sender (e.g. a bank). Service messages relate to an existing customer relationship (alerts, updates). Service and transactional traffic is not blocked by DND, but every category still needs a registered header and template.
- Promotional: marketing only; DND-scrubbed; 10am–9pm window.
- Transactional: OTP / bank-and-transaction confirmations.
- Service: alerts and updates within an existing relationship.
- All categories require a registered header + content template.
Content and timing rules
Under TCCCPR 2018 the time bands outside 10:00am–9:00pm are off by default for promotional SMS, so operators block promotional traffic outside that window unless the recipient has opted into other hours. Content must match the approved template variables, and headers must reflect the registered brand. Purely promotional headers are commonly numeric (140-series / 1XXXXX) while service and transactional traffic uses alphabetic headers, per operator practice. Unregistered headers, template mismatches and unsolicited promotional content are filtered.
- Promotional window: 10:00am–9:00pm.
- Content must match the approved Content Template (variables allowed).
- Promotional headers typically numeric; service/transactional alphabetic.
- Template mismatches and unregistered headers are scrubbed.
Consent, opt-out and the DND registry
Subscribers manage their preferences through the DND (Do Not Disturb) / DND 2.0 registry, blocking or category-filtering promotional traffic. For consent-based promotional sending, senders register a Consent Template on DLT and capture verifiable opt-in; digital consent acquisition is built into the framework. Recipients can revoke consent, and complaints flow back through the operators to TRAI, with unregistered telemarketers facing blacklisting.
- DND registry lets subscribers block/filter promotional SMS.
- Consent Templates on DLT evidence and manage opt-in.
- Subscribers can revoke consent at any time.
- Persistent violators are blacklisted across the DLT ecosystem.
Data protection: the DPDP Act 2023
Beyond telecom rules, senders handling recipients' personal data fall under the Digital Personal Data Protection Act, 2023 (DPDP Act). It requires a lawful basis — generally the data principal's consent — to process personal data such as mobile numbers, obliges clear notice and easy withdrawal of consent, and creates data-principal rights and breach obligations enforced by the Data Protection Board of India. Confirm current commencement and rule details, as provisions are being operationalised in stages.
- Law: Digital Personal Data Protection Act, 2023 (DPDP Act).
- Consent-based processing; clear notice and easy withdrawal.
- Data-principal rights and breach obligations apply.
- Enforced by the Data Protection Board of India.
Operator landscape and enforcement
All A2P traffic terminates through the licensed operators — Reliance Jio, Bharti Airtel, Vodafone Idea (Vi) and BSNL — and each runs its DLT onboarding. Enforcement is largely automated: unregistered headers, unapproved templates, out-of-window promotional sends and DND violations are blocked or scrubbed in-network, and repeat offenders are blacklisted. Confirm exact registration fees, security deposits and turnaround with your operator or provider at onboarding.
- Operators: Jio, Airtel, Vi and BSNL.
- Enforcement is automated: header/template scrubbing, DND filtering.
- Repeat violators are blacklisted across the DLT ecosystem.
- Confirm current fees, deposits and timelines at registration.
- Submit your KYC packTrade licence, authorisation letter and sample messages
- BroadNet files the applicationWith the operators or the regulator, as the market requires
- Review and approvalTypical lead time3-7 business days (DLT header registration)
- Send under your brandYour approved sender ID on every message
Technical facts for India
Network codes, message lengths and sender-ID rules in one table. Segment lengths are the GSM standard values (3GPP TS 23.038).
| Mobile country code (MCC) | 404 / 405 |
|---|---|
| Dialling code | +91 |
| Operators (MCC-MNC) |
|
| SMS length, GSM-7 (Latin alphabet) | 160 characters in a single SMS; 153 per part when concatenated |
| SMS length, UCS-2 (Arabic, Cyrillic and other scripts) | 70 characters in a single SMS; 67 per part when concatenated |
| Regulator | TRAI (Telecom Regulatory Authority of India) |
| Sender-ID rules | TRAI DLT registration mandatory: Header (sender ID), Entity, and Template all pre-registered on the DLT blockchain. Every message variant scrubbed at operator firewall. |
| Sender-ID lead time | 3-7 business days (DLT header registration) |
How to register a sender ID in India
What to prepare, who approves it and how long it takes. Send us the documents below and BroadNet coordinates the registration with the operators, the regulator or the registry, as the market requires.
- Who approves
- The operators' DLT platforms (Jio, Airtel, Vi and BSNL) under TRAI's TCCCPR 2018. Your business is approved as a Principal Entity, each header is approved, and every content template is approved on the platform. Registration on one operator's DLT platform is recognised by all four.
- Typical lead time
- 3–7 business days for the header; 1–3 business days per content template
- Renewal
- Principal Entity registration is valid for one year, with a 30-day grace period. Headers have lifetime validity but return to the pool after 90 days without use.
Document checklist
- Business PAN
- Business proof documents, such as the certificate of incorporation and GST registration
- Name, mobile number and email of the authorised person
- Letter of Authorisation signed by your authorised signatory, naming the telemarketer that will act for you
- The header (sender ID) you want, with its category: promotional, transactional or service
- Content templates that include your brand name, plus consent templates for promotional traffic
Steps
- 1
Register your business once as a Principal Entity on any operator's DLT platform, with your business PAN, business proofs and line of business. The entity registrar typically verifies the details within 72 hours of the fee being paid.
- 2
Choose the header: exactly six characters, with no spaces or special characters. Promotional headers are six digits; transactional and service headers are six letters. A header is tied to its category and cannot be used for another.
- 3
Register a content template for every message pattern. Each template must carry your brand name, and promotional sending also needs a consent template.
- 4
Sign a Letter of Authorisation naming the registered telemarketer that will deliver your traffic. BroadNet coordinates the header and template registrations during onboarding, and every message is checked against your registered header and templates before delivery.
- 5
Send only within your registered line of business. Promotional SMS goes only to recipients who are not on the DND registry or who have given consent, and by default only between 10:00am and 9:00pm IST.
Common reasons for rejection
- A content template that does not include the brand name
- Message content that does not match an approved template
- Promotional content sent under a transactional or service header, or mixed into a service message
- A header that is not six characters, or that contains spaces or special characters
- Content outside the Principal Entity's registered line of business
Official sources
Requirements are set by the regulator and the operators and can change. Check the official sources, or ask our team, before you file.
More on India
Compare A2P SMS rules across the region.
Each market pairs a regulatory playbook with its live coverage and operator-direct routing detail.
India rules: promotional vs. transactional/service SMS
| Capability | Promotional / marketing | Transactional / service (OTP, alerts) |
|---|---|---|
| DLT Header + Content Template required | ||
| DND scrubbing applies | — | |
| 10am–9pm sending window | — | |
| Verifiable opt-in / Consent Template | — | |
| Header category | Promotional | Transactional / Service |
| Content must match approved template |
Common questions
What is DLT registration and is it mandatory in India?
Do transactional and OTP messages need registration too?
What are the permitted hours for promotional SMS in India?
How does the DND registry affect my campaigns?
What is a Content Template and why did my message get blocked?
Which data protection law applies to SMS in India?
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