# India DLT registration in 2026: the complete guide, updated for header suffixes and URL whitelisting

> India DLT registration explained and updated for 2026: TRAI's TCCCPR 2018 rules, Principal Entity, header and template registration, scrubbing, the -P/-S/-T/-G header suffixes, URL/APK whitelisting, #url# variable tagging, the 140 and 1600 series, and what foreign senders must do.

- Canonical URL: https://www.broadnet.me/blog/india-dlt-registration-guide-2026
- Language: en
- Last updated: 2026-10-20
- Publisher: BroadNet (https://www.broadnet.me)

- Published: 2026-08-03
- Author: BroadNet Editorial Team

India DLT registration is the mandatory process — under TRAI's TCCCPR 2018 regulation — of registering your business, your sender headers, your consent wording and every message template on the telecom operators' blockchain-based Distributed Ledger Technology (DLT) platforms before you can send A2P SMS in India. Since 2024 TRAI has tightened it further: every URL, APK and OTT link must be whitelisted, the sender-to-telemarketer chain must be traceable, variables must be tagged, and headers now end in a -P, -S, -T or -G suffix that tells recipients what kind of message it is.

> Updated 26 September 2026 with TRAI's 2024–2026 changes. This guide summarises public TRAI and DoT texts; it is general information, not legal advice — confirm specifics with your operator's DLT portal or counsel.

> New to the terms? Start with [what DLT registration is](https://www.broadnet.me/answers/what-is-dlt-registration-india), [what A2P SMS is](https://www.broadnet.me/answers/what-is-a2p-sms) and the country summary on [India SMS regulations](https://www.broadnet.me/regulations/india). This guide is the long-form process behind them.

## Key takeaways

- Registration chain: Principal Entity (PE) → headers → consent templates → content templates. The PE ID, header and Content Template ID travel with every message.
- Since 1 October 2024, messages carrying URLs, APKs or OTT links that are not whitelisted are not delivered.
- Since 11 December 2024, SMS sent through an unregistered or undefined telemarketer chain is rejected.
- The TCCCPR (Second Amendment) Regulations, 2025 (12 February 2025) add header suffixes -P, -S, -T and -G, require an opt-out in the same promotional message, and tighten complaint handling and penalties.
- Variables must be pre-tagged — a variable tagged #url# may carry only a URL — and templates need at least 30% fixed text.
- International incoming SMS with an alphanumeric header or a +91 origin must not be delivered, so brands reach Indian users through registered domestic routes.

## What changed in 2024–2026?

| Date | Change | Official source |
|---|---|---|
| 20 Aug 2024 | TRAI direction: whitelisting of URLs, APKs, OTT links and call-back numbers; chain traceability; wrong-category templates blacklisted; misuse suspends all of a sender's headers and templates | PIB release 2046872 |
| 1 Oct 2024 | Non-whitelisted URLs, APKs and OTT links blocked (extended from 1 Sep 2024); call-back numbers timeline to be fixed separately | PIB release 2050109 |
| 11 Dec 2024 | SMS through unregistered telemarketer paths rejected (after extensions to 30 Nov and 10 Dec 2024) | PIB release 2086103 |
| 12 Feb 2025 | TCCCPR (Second Amendment) Regulations, 2025: -P/-S/-T/-G suffixes, 140 series for promotional and 1600 series for service/transactional calls, opt-out in every promotional message, new complaint and penalty rules | TRAI notification RG-25/(25)/2023-QoS; PIB release 2102413 |
| 18 Nov 2025 | Variable pre-tagging such as #url#; existing templates to be modified within 60 days | TRAI press release 133/2025 |
| 19 Nov 2025 | 1600-series deadlines for banks, NBFCs, SEBI and PFRDA entities (1 Jan – 15 Mar 2026) | TRAI press release 135/2025 |
| 17 Dec 2025 | Insurers to move service and transactional calls to 1600 by 15 Feb 2026 | TRAI press release 151/2025 |

## What do -P, -S, -T and -G mean at the end of an SMS header?

They tell the recipient what kind of commercial message it is. The Second Amendment to Schedule-I says the type of communication "can be identified by Recipients from the Header structure or its format by suffixing "-P", "-S", "-T", and "-G" for Promotional, Service, Transactional, and Government Messages, respectively". Under the amendment's commencement clause, this part came into force sixty days after publication in the Official Gazette; operators apply the suffix to the header you registered, so you do not register a second header for it.

| Suffix | Category | What it signals to the recipient |
|---|---|---|
| -P | Promotional | Marketing; only to non-DND numbers, with an opt-out in the message |
| -S | Service | Updates tied to an existing relationship or explicit consent |
| -T | Transactional | Messages triggered by a transaction, such as bank OTPs and alerts |
| -G | Government | Messages from government entities |

## The four-step DLT registration chain

DLT onboarding follows a fixed sequence. TRAI's Advice to Senders lists it as registration as a Principal Entity, assignment of header, registration of content template, transmission of PE ID, header and Content ID with each message, and — where applicable — registration of a consent template and acquisition of consumer consent. You complete registration once on any operator's portal and it propagates across the shared ledger, so you do not repeat the entity step separately for Jio, Airtel, Vi and BSNL.

### 1. Principal Entity (PE) registration

The Principal Entity is the business that owns the communication — the brand whose messages go out. You register the PE on an operator DLT portal by submitting KYC: company identity documents, GST and PAN details, and an authorised signatory. Once approved, the PE is issued a unique Entity ID that anchors every header and template you register afterwards.

### 2. Header (sender ID) registration

A header is the sender ID that appears on the message. TRAI's Advice to Senders describes it as an alphanumeric string of a maximum of 11 characters, giving examples such as VD-KOTAKB. Headers are registered against your Entity ID and bound to a category, so most enterprises register a small set — one per category they actually need. A single content template cannot be linked to multiple headers.

### 3. Consent Template registration

Where you rely on the recipient's consent — principally promotional and service-explicit messaging — you register a Consent Template that captures how and for what the customer opted in. Under the 2025 amendment a sender cannot seek consent again for 90 days after a customer opts out, and consent given during an ongoing transaction lasts seven days.

### 4. Content Template registration

Finally, you register every message you intend to send as a Content Template, mapped to a header and a category. The 2025 rules require at least 30% of a template to be fixed text, a justification for more than three variables, and every variable to be pre-tagged by type. At send time the operator matches your live message against the approved pattern; if the fixed text differs or a variable carries the wrong kind of content, the message is rejected.

## How do I whitelist URLs, APKs and call-back numbers on DLT?

You submit them on the DLT portal against your entity and templates before you send. TRAI's direction of 20 August 2024 said access providers would be "prohibited from transmitting messages containing URLs, APKs, OTT links, or call back numbers which are not whitelisted"; after a one-month extension the block took effect on 1 October 2024 for URLs, APKs and OTT links, with the timeline for call-back numbers to be fixed separately. Senders must also undertake that their whitelisted links are not malicious.

| In the message | Delivered? | Why |
|---|---|---|
| A full URL on a domain you whitelisted, inside a #url# variable | Yes | Matches the whitelist and the tagged variable type |
| The same URL placed in a variable tagged for a name or amount | No | The variable type does not match its content |
| A link on a domain nobody whitelisted | No | Blocked since 1 October 2024 |
| An APK or app-store link that is not whitelisted | No | APKs and OTT links follow the same rule |
| A generic public short link | High risk | Only whitelisted URLs pass; regulators flagged misuse of shortened URLs in October 2025 |

If you want short links in SMS, use a branded short domain you control and whitelist it like any other URL — see [branded short links for SMS](https://www.broadnet.me/blog/branded-short-links-sms-attribution-2026).

## What is variable tagging?

Variable tagging means declaring what each placeholder in a template may contain. TRAI's press release of 18 November 2025 gives the example that "tagging a variable as #url# implies that the variable contains a URL", and required existing templates to be modified within 60 days, after which non-compliant templates are rejected. Other tag names you see on operator portals are portal conventions; check the exact list on the portal you use.

## Message categories: getting classification right

DLT sorts A2P traffic into categories, and the category dictates who you may message and whether Do-Not-Disturb (DND) preferences apply. TRAI's August 2024 direction said content templates registered under the wrong category will be blacklisted, and repeat offences lead to a one-month suspension — so the mapping below matters as much as the templates themselves. Under the 2025 amendment, a message that mixes promotional and other content is treated as promotional.

| Category | Consent / basis | Typical content | DND |
|---|---|---|---|
| Promotional (-P) | No prior consent, but only to non-DND numbers; opt-out in the message | Offers, marketing, cross-sell | DND-scrubbed; time-window rules apply |
| Service — Implicit (-S) | Implied by an existing customer relationship | Order, delivery and account alerts, general OTPs | Not DND-scrubbed |
| Service — Explicit (-S) | Explicit opt-in via a registered Consent Template | Promotional-style updates to consented users | Verified against the consent registry |
| Transactional (-T) | Triggered by a transaction; reserved category | Banking OTPs and alerts from regulated financial entities | Not DND-scrubbed |
| Government (-G) | Government senders | Public-service messages | — |

The one-time passcodes an e-commerce app or SaaS product sends generally fall under Service — Implicit, not Transactional. Choosing the wrong bucket is a common cause of blocked OTPs.

## DLT scrubbing and traceability: how real-time matching works

Scrubbing is the real-time check the operator performs on every A2P message before it is delivered: the header (registered to this entity and category?), the content template (does the message match an approved template and its tagged variables?), any URL, APK or call-back number (whitelisted?), and — for promotional and service-explicit traffic — DND and consent status. Since 11 December 2024 the telemarketer chain is checked too: SMS sent through unregistered paths is rejected, so every telemarketer between you and the operator must be declared on DLT.

Misuse is punished at the sender level. Under the August 2024 direction, when a header or template is misused, traffic from all of that sender's headers and templates is suspended until the sender takes legal action and files a report. Under the 2025 amendment, five complaints against a sender in ten days trigger action; a first violation bars outgoing services for 15 days, and later violations mean one-year disconnection and blacklisting. Customers can now complain within seven days of receiving spam.

## What are the 140 and 1600 series?

They are the number ranges for commercial voice calls. The 2025 amendment keeps the 140 series for promotional calls and designates the 1600 series for transactional and service calls. TRAI then set deadlines for regulated financial entities: commercial banks by 1 January 2026; large NBFCs, payments banks and small finance banks by 1 February 2026; remaining NBFCs, co-operative and regional rural banks by 1 March 2026; mutual funds, AMCs and pension entities by 15 February 2026; qualified stockbrokers by 15 March 2026; and insurers by 15 February 2026. TRAI clarified in July 2026 that tagging, blocking or filtering calls from 1600-series numbers is not permitted.

## Does CNAP affect business calls?

Calling Name Presentation (CNAP) shows a caller's name on the recipient's screen. TRAI sent its recommendations to the Department of Telecommunications on 23 February 2024; a DoT letter of 21 November 2025 refers to a CNAP trial, allows business and bulk connections to display a verified preferred name, and leaves the commercial rollout to be decided by DoT. Watch for the DoT announcement before planning around it.

## What changes for international and foreign senders?

The international route is not an alternative to DLT. Regulation 37 of the amended TCCCPR says every access provider and international long-distance operator "shall ensure that no international incoming SMS containing alphanumeric header or originating country code +91 is delivered through its network". In other words, a branded sender ID cannot reach Indian users over an international route at all.

Foreign brands therefore take the domestic path: register as a Principal Entity where the operator portals accept overseas KYC, or onboard through a registered Indian telemarketer that maps the brand's Entity ID, headers and templates through a declared chain. Either way the header, templates and whitelisted links must be on the ledger before a single message flows — see [India SMS regulations](https://www.broadnet.me/regulations/india) and indicative [India SMS pricing](https://www.broadnet.me/pricing/sms/india).

## A practical onboarding checklist for 2026

1. Register your business as a Principal Entity on an operator DLT portal and obtain your Entity ID.
2. Register the headers you need (alphanumeric, up to 11 characters including prefix), one per category you actually send.
3. Register Consent Templates for any promotional or service-explicit messaging that relies on opt-in.
4. Register every message as a Content Template with at least 30% fixed text and every variable pre-tagged (#url# for links).
5. Whitelist every domain, APK and call-back number your messages carry; use a branded short domain rather than a generic shortener.
6. Declare every telemarketer in your delivery chain so traceability checks pass.
7. Classify each flow correctly and add an opt-out to every promotional message.
8. Move service and transactional voice calls to 1600-series numbers if you are a regulated financial entity.

> BroadNet routes A2P SMS into India over direct operator connections and handles DLT onboarding — Principal Entity, headers, consent and content templates — so registered traffic clears scrubbing predictably. It is part of direct routing to 200+ countries through 1,000+ operator connections at a 99.99% platform SLA, since 2003. See [A2P SMS](https://www.broadnet.me/products/a2p-sms), the [OTP API](https://www.broadnet.me/products/otp) and our full [coverage](https://www.broadnet.me/coverage).

## Frequently asked questions

### How do I register for DLT in India?

Register your business as a Principal Entity on any operator's DLT portal (Jio, Airtel, Vi or BSNL), submitting KYC such as GST, PAN and authorised-signatory details. Once approved you receive an Entity ID, then register your headers, consent templates and every content template you plan to send, and whitelist the URLs, APKs and call-back numbers they carry.

### What do -P, -S, -T and -G mean at the end of SMS headers?

They are the category suffixes introduced by the TCCCPR (Second Amendment) Regulations, 2025: -P for promotional, -S for service, -T for transactional and -G for government messages. They let recipients see what kind of message they received from the header alone.

### Why was my SMS with a short link rejected?

Since 1 October 2024, operators do not deliver messages containing URLs, APKs or OTT links that are not whitelisted on DLT. A generic public short link usually fails that check; whitelist a branded domain you control and put the link in a variable tagged #url#.

### How do I whitelist URLs, APKs or call-back numbers on DLT?

Submit them on your operator's DLT portal against your entity and templates before sending, with the undertaking that they are not malicious. URLs, APKs and OTT links have been enforced since 1 October 2024; TRAI said the timeline for call-back numbers would be fixed separately.

### What is variable tagging in DLT templates?

It is declaring the type of each variable in a content template, so the operator can check what it carries — for example, a variable tagged #url# may only contain a URL. TRAI required existing templates to be updated within 60 days of its 18 November 2025 press release.

### Do international senders need DLT registration?

Yes, if they want a branded sender ID. International incoming SMS with an alphanumeric header or a +91 origin must not be delivered in India, so foreign brands register as a Principal Entity or onboard through a registered Indian telemarketer and send over a declared domestic route.

### What is the 1600 series?

It is the number range for service and transactional voice calls, while the 140 series stays for promotional calls. Banks, NBFCs, insurers, mutual funds, pension entities and qualified stockbrokers had to move to 1600 numbers between 1 January and 15 March 2026, depending on their category.

### What is DLT scrubbing?

It is the real-time check every Indian operator runs before delivering an A2P message: header, content template, tagged variables, whitelisted links, the declared telemarketer chain and, where relevant, DND and consent status. Anything that fails is blocked at the operator, not delivered.

## Sources

- TRAI — Advice to Senders (updated 25 September 2026): [trai.gov.in](https://trai.gov.in/advice-to-senders).
- TRAI — Telecom Commercial Communications Customer Preference (Second Amendment) Regulations, 2025, notification of 12 February 2025: [trai.gov.in](https://trai.gov.in/sites/default/files/2025-02/Regulation_12022025.pdf); press release: [pib.gov.in](https://www.pib.gov.in/PressReleasePage.aspx?PRID=2102413).
- TRAI direction on whitelisting and traceability, 20 August 2024: [pib.gov.in](https://www.pib.gov.in/PressReleasePage.aspx?PRID=2046872); extension to 1 October 2024 (30 August 2024): [pib.gov.in](https://pib.gov.in/PressReleasePage.aspx?PRID=2050109).
- TRAI on traceability enforcement from 11 December 2024 (19 December 2024): [pib.gov.in](https://www.pib.gov.in/PressReleasePage.aspx?PRID=2086103).
- TRAI press release 133/2025 on variable tagging (18 November 2025): [trai.gov.in](https://www.trai.gov.in/sites/default/files/2025-11/PR_No.133_of_2025.PDF).
- TRAI press release 135/2025 on 1600-series deadlines (19 November 2025): [trai.gov.in](https://www.trai.gov.in/sites/default/files/2025-11/PR_No.135of2025.pdf); 151/2025 for insurers (17 December 2025): [trai.gov.in](https://trai.gov.in/sites/default/files/2025-12/PR_No.151of2025.pdf); 91/2026 on 1600 call handling (10 July 2026): [trai.gov.in](https://www.trai.gov.in/sites/default/files/2026-07/PR_No91of2026.pdf).
- Department of Telecommunications — CNAP letter of 21 November 2025: [dot.gov.in](https://www.dot.gov.in/static/uploads/2026/03/455cd2a9081b7ec15886e2a2c48f79f7.pdf).
- BroadNet — [India SMS regulations](https://www.broadnet.me/regulations/india), [A2P SMS](https://www.broadnet.me/products/a2p-sms), and [what A2P SMS is](https://www.broadnet.me/answers/what-is-a2p-sms).