India: TRAI and DLT
TCCCPR: the rulebook behind commercial SMS in India
Every commercial SMS and voice call in India is governed by the Telecom Commercial Communications Customer Preference Regulations, 2018 (TCCCPR), issued by the Telecom Regulatory Authority of India (TRAI) on 19 July 2018. TRAI sets the rules, and each access provider enforces them through its own Distributed Ledger Technology (DLT) platform and Codes of Practice.
Under TCCCPR, a business (the Sender or Principal Entity) can only send commercial communication after registering itself, its headers (sender IDs) and its content templates on DLT. Each message is scrubbed in real time against those registrations and the recipient's preferences and consents. Customers can complain about unsolicited commercial communication (UCC) through 1909 or the TRAI DND app.
Key regulatory milestones
| Instrument | Date | What it changed |
|---|
| TCCCPR, 2018 (6 of 2018) | 19 July 2018 | DLT-based registration of senders, headers, templates, consent and preferences |
| TRAI direction on URL/APK/OTT whitelisting | Issued 20 Aug 2024, enforced from 1 Oct 2024 | Messages with non-whitelisted links blocked |
| Message traceability (PE-TM chain) | Enforced from 11 Dec 2024 | Messages with an undeclared or mismatched telemarketer chain rejected |
| TCCCPR (Second Amendment) Regulations, 2025 | 12 Feb 2025 | New message categories, -P/-S/-T/-G header suffixes, stricter complaint handling and penalties |
| TRAI direction on pre-tagging of template variables | 18 Nov 2025 | Every template variable must carry a typed tag; failing messages rejected after a 60-day logger period |
| TRAI direction on 1600-series for BFSI | 19 Nov 2025 | Phased move of service and transactional calls by RBI, SEBI and PFRDA-regulated entities to 1600-series |
| TCCCPR (Third Amendment) Regulations, 2026 | Announced 18 Sep 2026 | AI/ML-assisted UCC detection, A2P call rules, appeals, faster action on header/template misuse |
The Second Amendment: four message categories
The Telecom Commercial Communications Customer Preference (Second Amendment) Regulations, 2025, dated 12 February 2025, rewrote the definitions every DLT template is classified by. The headline change is a four-way split of commercial communication:
| Category | Definition (summary of the regulation) | Consent | Header suffix |
|---|
| Transactional | Sent to a customer in response to a customer-initiated transaction within thirty minutes of the transaction, e.g. OTPs from banks, e-commerce or app logins, transaction alerts and confirmations, balance alerts after a transaction, refund information | Not required | -T |
| Service | (i) Information to an existing customer about a product or service: warranty, recall, software upgrade, safety or security, periodic balance alerts, delivery updates; or (ii) messages that facilitate an ongoing purchase after explicit consent, valid for seven days | Not required for (i); explicit consent for (ii) | -S |
| Promotional | Any communication containing promotional material or advertisement; must carry an opt-out option in the same message | Delivered only where preferences allow or explicit digital consent exists | -P |
| Government | Sent on the directions of the Central or State Government through DLT | Not required | -G |
Mixing rule: if promotional content is mixed into a transactional or service message, the whole message is treated as promotional. A transactional message that carries service information is treated as service. A delivery update sent hours after the order is a service message, not transactional, because it falls outside the thirty-minute window.
Complaints and enforcement
- Recipients must report UCC within seven days of receiving it; customers do not need to be on the DND preference register to complain against unregistered telemarketers.
- Action against an unregistered sender is triggered by complaints from five or more unique recipients in ten days (previously ten complaints in seven days).
- First proven violation: all the sender's outgoing telecom resources are barred for fifteen days. Repeat violations: disconnection across all operators for one year and blacklisting.
- Headers and content templates unused for ninety days are temporarily deactivated and can be reactivated on request.
- Access providers face graded financial disincentives for misreporting UCC, wrongly closing valid complaints and approving non-compliant headers or templates.
The Third Amendment: AI-led spam enforcement
On 18 September 2026 TRAI announced the Telecom Commercial Communications Customer Preference (Third Amendment) Regulations, 2026, following a consultation that opened on 13 March 2026. Its salient features, as published in TRAI's press release, include:
AI/ML spam detection
Operators must flag CLIs with a high probability of sending UCC and share them across networks. Five or more flagged CLIs of a sender in ten days trigger graded action, from KYC re-verification to disconnection.
Faster complaint action
Action can start at three unique complaints in ten days when the sender's CLI is also flagged by the operator's AI system. Consumers gain an appeal route within fifteen days.
A2P calls regulated
Calls placed by software, auto-dialers or robo-calls must be pre-declared to the operator with the CLIs used; undeclared A2P calls are treated as UCC.
Header and template misuse
Misused headers or templates are suspended within six hours. Senders must take remedial steps and report to law enforcement; a telemarketer at fault is disconnected for a year and blacklisted.
It also recognises verifiable legacy consents once registered on the operators' consent platform, allows commercial messages for seven days after a written or digital customer inquiry, and bars call-management apps from blanket spam-tagging the 140xx, 1600xx and 1601xx series.
Clause-wise effective dates for the Third Amendment are set in its Gazette text. SMSGatewayHub will apply operator implementation notices as they are issued; check with your account manager before changing live flows.
The DLT ecosystem: who registers what
DLT is the shared ledger operators use to record every party and asset in a commercial message. The building blocks:
Principal Entity (PE)
The business that sends commercial communication and is accountable for it. Registers with KYC documents and receives a PE ID.
Header (sender ID)
The alphanumeric or numeric string shown as the sender. Each header is registered by the PE and now displays a category suffix.
Content template
The approved message text with fixed content and typed variables. One content template can be linked to only one header.
Consent template
The text shown to a customer when seeking consent, stating the purpose and the brand. Consent is sought through the 127xxx short code.
Telemarketer (TM)
The registered aggregator or delivery partner that submits traffic to operators, such as SMSGatewayHub's operator-registered platform.
PE-TM chain binding
The PE declares every telemarketer in its delivery chain. Since 11 December 2024, messages with an undeclared or mismatched chain are rejected.
CTA whitelist
URLs, APK and OTT links and callback numbers the PE registers as safe. Only whitelisted values pass scrubbing.
Preference and consent registers
Records of each subscriber's DND preferences and digital consents, checked in real time before a promotional message is delivered.
SMSGatewayHub helps you complete DLT registration, declare the PE-TM chain and map headers and templates in your panel. See our guide to PE-TM chain binding.
Service Explicit now sits under Promotional
DLT previously had Service Explicit (consent-based) and Service Implicit (existing customer) categories. Because explicit-consent service messages were often misused for offers, the Second Amendment narrowed the service definition and limited explicit consent to seven days.
Operators have since stopped accepting new Service Explicit templates and migrated existing ones to the Promotional category, so they carry the -P suffix and follow promotional scrubbing and delivery-time rules. Informational messages to existing customers continue as Service (-S) templates.
If your old Service Explicit templates carried any offer, coupon or cross-sell text, they will now behave as promotional traffic. Re-register purely informational content as Service, and move marketing content to Promotional with consent. Our
Service Explicit vs Service Implicit guide covers the migration in detail.
Typed variable tagging in content templates
On 18 November 2025 TRAI directed all access providers to require that each variable in every SMS content template is pre-tagged with its content type, purpose and validation rule. Tagged values are then validated at scrubbing time, and links and numbers are matched against your whitelisted CTAs. The tags listed in the direction's annexure:
| Tag | Use for | Validation at scrubbing |
|---|
{#numeric#} | OTPs, amounts, quantities, account digits | Digits only, no letters or special characters |
{#alphanumeric#} | Order, booking and ticket IDs | Letters and numbers with length validation |
{#url#} | Website, tracking or short links | Must match a registered static, dynamic or short-URL CTA |
{#urlott#} | App download, APK or OTT links | Must match a registered OTT or APK CTA |
{#cbn#} | Callback numbers | Must match a registered mobile, landline or toll-free CTA |
{#email#} | Support or reply email addresses | Must be a valid email format |
Compliance timeline
- New templates registered from ten days after the direction must be tagged before approval.
- Operators had thirty days to start scrubbing tagged variables against the CTA whitelist.
- Existing templates had sixty days from the start of tag scrubbing to be modified.
- During those sixty days messages ran in logger mode: delivered, but with fault records. After that window, any message failing variable validation is rejected outright.
Variables should still be used sparingly. The Second Amendment allows more than the usual number of variables only on recorded justification, requires each such variable to be pre-tagged and keeps at least thirty percent of the template as fixed content. Read our explainer on mandatory variable tagging and the DLT template registration process for worked examples.
Whitelisting URLs, APKs, OTT links and callback numbers
Since 1 October 2024, operators block any commercial SMS containing a URL, APK or OTT link that the sender has not whitelisted on DLT, under a TRAI direction issued on 20 August 2024. The Second Amendment extended scrubbing to callback numbers and requires the sender to submit an undertaking that whitelisted links are not malicious.
- List every domain, short link, app-store or APK link and callback number your templates use.
- Upload them as CTAs on your operator DLT portal, using your own or a trusted short-link domain.
- Tag each link variable as
{#url#} or {#urlott#} and each phone variable as {#cbn#}. - Re-test after any domain, shortener or support-number change.
Public URL shorteners that are not whitelisted by you are a common cause of silent rejections. Use a branded short domain registered against your own Principal Entity.
Consent, DND preferences and delivery timing
Promotional SMS is delivered only to subscribers who have not blocked the relevant category on the preference (DND) register, or who have given explicit digital consent. Consent acquired through the operators' Digital Consent Acquisition (DCA) facility overrides the recipient's preference for that sender.
- Consent-seeking messages are sent through the 127xxx short code and must name the Principal Entity or brand and the scope of consent.
- The confirmation message must explain how to revoke consent; a customer who revokes can opt in again at will, but the sender can re-request consent only after ninety days.
- Every promotional message must include an opt-out option in the same message.
- Customers can register their unwillingness to receive any consent-seeking messages.
- Transactional and government messages are not subject to promotional DND scrubbing.
Delivery window: operators deliver promotional SMS only during daytime hours, enforced on DLT as 10 AM to 9 PM; promotional traffic submitted outside that window is rejected. Recipients may also restrict delivery further by time band and day type. Transactional, service and government messages are delivered round the clock.
140-series and 1600-series voice numbering
TCCCPR also covers commercial voice calls. Under the Second Amendment, promotional calls, including auto-dialer and robo-calls, are allowed only from 140-series numbers, while service and transactional robo-calls should use the 1600-series allotted by the Department of Telecommunications, or another series allotted for the purpose. Senders must declare auto-dialer or robo-call use to their operator in advance.
| Series | Purpose | Who uses it |
|---|
| 140xx | Promotional voice calls | Registered telemarketers and senders making marketing calls |
| 1600xx / 1601xx | Service and transactional calls | Banks, financial institutions, government and other authorised entities |
On 19 November 2025 TRAI directed BFSI entities regulated by RBI, SEBI and PFRDA to move service and transactional calls to 1600-series in phases: commercial banks by 1 January 2026; large NBFCs, payments banks and small finance banks by 1 February 2026; mutual funds, AMCs, CRAs and pension fund managers by 15 February 2026; other NBFCs, co-operative banks and regional rural banks by 1 March 2026; and qualified stockbrokers by 15 March 2026.
Running
voice SMS and OBD campaigns? Tell us whether the calls are promotional or service so we can map them to the correct number series and DLT declarations.
Sender compliance checklist
Use this checklist before launching any new SMS flow in India:
- Register your organisation as a Principal Entity on DLT and keep KYC details current.
- Register headers that reflect your brand; avoid unused headers, which are deactivated after ninety days.
- Classify each template correctly: transactional only for customer-initiated events within thirty minutes, service for informational updates, promotional for anything with an offer.
- Tag every variable with the correct typed tag and keep templates mostly fixed text.
- Whitelist every URL, APK or OTT link and callback number used in templates.
- Declare your full PE-TM chain, including SMSGatewayHub, on the DLT portal.
- Collect promotional consent via DCA where you need to reach DND subscribers, and include an opt-out in every promotional message.
- Schedule promotional sends inside the daytime window and keep consent and complaint records.
Ready-made formats are in our DLT sample templates library and the template approval guide.
Common DLT rejection reasons and fixes
| Rejection reason | Likely cause | Fix |
|---|
| Template mismatch | Sent text differs from the approved template, including spaces or punctuation | Copy the approved text exactly and only change variable values |
| Variable validation failed | Value does not match its tag, e.g. letters in {#numeric#} | Re-tag the variable or correct the data sent |
| URL or callback not whitelisted | Link domain or number not registered as a CTA | Add the CTA on DLT and retest |
| Header or template inactive | Not used for ninety days or suspended | Request reactivation on the DLT portal |
| PE-TM chain mismatch | Telemarketer not declared in the chain | Update the chain declaration to include every TM |
| Header-template mismatch | Template linked to a different header | Link each template to exactly one header |
| Promotional outside window or to DND | Send time outside daytime window, or no consent | Reschedule and scrub against consent |
For operator-specific codes and step-by-step resolutions, see DLT error codes and solutions. If you need hands-on help, DLT priority support connects you with our compliance desk.
Worldwide A2P SMS rules
How other countries regulate A2P SMS
Outside India, rules split into consent and marketing law and sender ID registration. Where rules are set by carriers rather than a regulator, we say so.
| Country | Regulator / framework | Sender ID rule | Consent rule | Notable requirement |
|---|
| USA | FCC (TCPA); carrier rules under CTIA guidelines | 10DLC brands and campaigns registered through The Campaign Registry; toll-free numbers verified; short codes approved per carrier | Prior consent for marketing texts under TCPA | Unregistered 10DLC traffic is filtered by carriers |
| Canada | CRTC (CASL) | Varies by operator | Express or implied consent | Identify the sender, include an unsubscribe, honour it within 10 business days |
| UK | ICO (PECR, UK GDPR); Ofcom for numbering | Varies by operator | Specific consent, or soft opt-in for similar products to existing customers | Never hide identity; offer an opt-out in every message |
| EU | National data and telecom regulators (GDPR, ePrivacy Directive) | Alphanumeric sender rules vary by country and operator | Prior consent, with a limited existing-customer exception | Lawful basis and records of consent |
| UAE | TDRA | Sender IDs registered through licensed providers; promotional senders start with AD | Prior explicit consent for marketing | Marketing SMS only between 7 AM and 9 PM UAE time; recipients block via 7726 |
| Saudi Arabia | CST | Alphanumeric sender IDs must be pre-registered | Varies by operator | Promotional sender IDs carry an -AD marker |
| Singapore | IMDA | Alphanumeric sender IDs must be on the SMS Sender ID Registry (SSIR) | Do Not Call Registry checks under the PDPA | Unregistered IDs labelled Likely-SCAM since 31 Jan 2023 |
| Australia | ACMA (Spam Act 2003) | Branded sender IDs registered on the SMS Sender ID Register | Consent, sender identification and unsubscribe | Unregistered IDs show as Unverified from 1 Jul 2026 |
| Indonesia | Komdigi; operators | Alphanumeric sender IDs registered with each operator | Varies by operator | Grey routes are blocked |
| Philippines | Operators | Sender ID registration required by major operators | Varies by operator | Letter of authorisation and sample content |
Carrier and regulator rules change often. Rows marked "varies by operator" have no single published national rule we could verify; confirm current requirements with our international desk before a launch.
Country notes for international senders
United States
The Telephone Consumer Protection Act, enforced by the FCC, requires prior consent for marketing texts. US carriers additionally require brand and campaign registration through The Campaign Registry for 10-digit numbers (A2P 10DLC), verification of toll-free senders, and opt-in, HELP and STOP handling in line with the CTIA Messaging Principles and Best Practices.
Canada, UK and EU
CASL requires consent, sender identification and an unsubscribe honoured within 10 business days (CRTC guidance). In the UK, marketing texts need specific consent or the soft opt-in, with a simple opt-out in every message (ICO guidance). EU sender ID formats differ by country and operator.
Middle East and Asia-Pacific
Official sources: TDRA FAQs for the UAE time window and 7726 blocking, IMDA for Singapore's SSIR, and ACMA for Australia's Sender ID Register. In Saudi Arabia, Indonesia and the Philippines, sender IDs are pre-registered with operators, and documents and lead times vary by network.
Reach overseas customers from the same panel with
international bulk SMS; our team checks sender ID and template requirements for each destination before you go live.
Staying compliant
How SMSGatewayHub keeps you compliant
SMSGatewayHub is a TRAI DLT-registered messaging provider operating since 2009, trusted by 10,000+ registered businesses. Compliance is built into onboarding, not left to you:
DLT registration help
Guided PE, header and template registration on operator portals, plus PE-TM chain declaration for our platform.
Template and tag checks
We review category, typed variable tags and fixed-text ratio before you submit, reducing rejections.
CTA whitelisting support
We help you list and whitelist every URL, APK, OTT link and callback number your templates use.
Global sender rules
Sender ID registration and consent guidance for international routes, from 10DLC to SSIR and TDRA.
Our infrastructure is ISO 27001, ISO 9001:2015 and SOC 2 certified and VAPT tested; details are on the Trust Center. Answers to common account and DLT questions are on our FAQ page.
Frequently asked questions
What is TCCCPR?
TCCCPR is the Telecom Commercial Communications Customer Preference Regulations, 2018, issued by TRAI. It requires businesses to register on operator DLT platforms and governs headers, templates, consent, customer preferences and complaints for commercial SMS and calls in India. It has been amended in 2025 and 2026.
What do -P, -S, -T and -G at the end of an SMS header mean?
They show the category of the message: Promotional, Service, Transactional or Government. Operators add the suffix automatically from the DLT category of the template used, so senders only need to classify templates correctly.
What counts as a transactional SMS now?
A transactional message is one sent in response to a customer-initiated transaction within thirty minutes of that transaction, such as an OTP, a payment confirmation or a refund alert. Updates sent later, like delivery notifications, are service messages.
What happened to Service Explicit templates?
The amended rules narrowed service messages and limited explicit consent to seven days. Operators no longer accept new Service Explicit templates and have moved existing ones to the Promotional category, where they follow promotional scrubbing and timing rules.
Which variable tags must I use in DLT templates?
TRAI's direction of 18 November 2025 requires every variable to be pre-tagged. The tags are numeric, alphanumeric, url, urlott, cbn and email, written as {#numeric#} and so on. Values that do not match their tag, or links and numbers that are not whitelisted, fail scrubbing.
Do I need to whitelist links in my SMS?
Yes. Since 1 October 2024, operators block commercial SMS containing URLs, APKs or OTT links that the sender has not whitelisted on DLT, and the 2025 amendment extends scrubbing to callback numbers. Register every link and number as a CTA before sending.
Can I send promotional SMS to DND numbers?
Only if the recipient has given explicit digital consent through the operator's Digital Consent Acquisition facility. Without consent, promotional messages reach only subscribers who have not blocked that category, and only within the daytime delivery window.
What is PE-TM chain binding?
It is the declaration of every telemarketer between a Principal Entity and the operator. Since 11 December 2024, messages whose telemarketer chain is undeclared or does not match the declared chain are rejected.
Which numbers are used for commercial voice calls in India?
Promotional calls must come from 140-series numbers. Service and transactional calls use the 1600-series, and TRAI has directed banks and other entities regulated by RBI, SEBI and PFRDA to adopt it in phases.
Does SMSGatewayHub help with international SMS compliance?
Yes. Our team advises on sender ID registration and consent rules for each destination, such as 10DLC in the USA, the SSIR in Singapore and TDRA rules in the UAE, before your international campaign goes live.
Need help staying compliant?
Our DLT team registers your entity, headers and templates and checks every campaign before it goes out.