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DLT Message Category

India's DLT classes for commercial SMS (transactional, service implicit or explicit, and promotional) that set consent, DND and sending-hour rules.

Also called: DLT category · DLT template category · SMS category (India) · Transactional vs promotional SMS

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Which DLT category does your SMS belong in?

Question 1 · up to 3

Does the message promote anything: an offer, a discount, a new product or a cross-sell?

Your answers

None yet — pick an answer to start down the tree.

Path map

Depth 0 of up to 3. Circles are questions, squares are outcomes.

All possible outcomes (4)

  • Transactional

    Bank OTPs and transaction alerts. Delivered to every number, DND included, at any hour, and shown with the -T suffix.

    Path: “No, it is purely informational” → “Yes” → “Yes, a bank transaction”

  • Service implicit

    Order and delivery updates, account alerts and non-bank OTPs with no promotional content. No explicit consent needed; reaches DND numbers at any hour.

    Path: “No, it is purely informational” → “Yes” → “No, any other business”

  • Service explicit

    Sent on the strength of explicit consent recorded on DLT, for example through digital consent acquisition. Scrubbing checks that consent before delivery.

    Path: “Yes, it promotes something” → “Yes, consent is recorded on DLT”

  • Promotional

    Marketing to anyone. Filtered against DND preferences, delivered only in daytime hours ending at 9 pm, from a promotional header with the -P suffix.

    Path: “Yes, it promotes something” → “No, it goes to a wider list”

Answer up to three questions about a message (does it promote anything, what triggered it, who sent it) to land on its DLT category and the delivery rules that come with it.

Question 1: Does the message promote anything: an offer, a discount, a new product or a cross-sell? 2 options.

01What is a DLT message category?

A DLT Message Category is the class every commercial SMS template is registered under on India's DLT platform. The framework built on TRAI's TCCCPR 2018 distinguishes four: transactional, service implicit, service explicit and promotional. The category travels with the template ID, and the operator's scrubbing applies that category's rules: who may receive the message, whether consent is needed, at what hours, and from which kind of header.

Transactional is the narrowest: OTPs and alerts a bank sends to complete a transaction its customer has started, delivered to every number, including those on the DND Registry, at any hour. Service implicit covers messages that follow from the customer's own action or existing relationship, such as order and delivery updates, account alerts and OTPs from businesses other than banks, with no promotional content; they need no explicit consent and are delivered regardless of DND. Service explicit covers messages sent only on the strength of the customer's explicit consent recorded on DLT, for example through Digital Consent Acquisition. Promotional covers marketing to anyone: it is filtered against the recipient's DND preferences and delivered only in a daytime window that closes at 9 pm.

These are not WhatsApp's template categories. Meta's marketing, utility and authentication categories decide how a WhatsApp template is reviewed and what each delivered message costs; DLT categories decide whether and when an SMS reaches a phone on an Indian network. A WhatsApp utility template and an SMS service-implicit template can carry the same order update, but each is classified under its own system, and approval in one says nothing about the other.

Key takeaways

  • A DLT message category classes each Indian commercial SMS template as transactional, service implicit, service explicit or promotional.
  • Transactional is reserved for bank OTPs and alerts that complete a customer's transaction, and reaches every number at any hour.
  • Service implicit covers non-promotional messages triggered by the customer's own action, such as order updates and most OTPs.
  • Service explicit needs consent recorded on DLT; promotional respects DND preferences and is delivered only in daytime hours ending at 9 pm.
  • DLT categories set SMS delivery rules on Indian networks; WhatsApp template categories set Meta's review and price.

02 · How it works, step by step

How does a DLT message category work?

  1. Step 1

    Start from the content

    Ask whether the message promotes anything. Any offer, discount or cross-sell makes it promotional, or service explicit if it goes only to customers whose consent is recorded on DLT.

  2. Step 2

    Check what triggered it

    Messages triggered by the customer's own action, such as a login, an order or a payment, are service implicit; a bank's OTP or alert that completes that customer's transaction is transactional.

  3. Step 3

    Register the template under that category

    The category is chosen per content template, and the template must be linked to a header registered for compatible traffic.

  4. Step 4

    Scrubbing applies the rules

    At send time, operators apply the category's rules: DND preferences, consent recorded on DLT and the daytime window for promotional traffic.

  5. Step 5

    The suffix shows it

    Recipients see the category as a suffix on the sender: -T for transactional, -S for service and -P for promotional, with -G for government.

03Why does a DLT message category matter?

Picking the wrong category is one of the fastest ways to lose SMS in India. An OTP filed as promotional never reaches DND subscribers and stops at 9 pm, while an offer filed as service implicit can get the template suspended. The category also shows on the handset as a header suffix, so customers see at a glance whether a message is a service alert or a sales pitch. Getting it right, template by template, protects delivery, customer trust and the sender's standing with operators.

04A DLT message category: key facts and limits

Categories
Transactional, service implicit, service explicit, promotional
Transactional
Bank OTPs and alerts completing a customer's transaction; all numbers, any hour
Service implicit
Triggered by the customer's action or relationship; no promotion; reaches DND numbers
Service explicit
Only with explicit consent recorded on DLT
Promotional
Filtered by DND preferences; daytime window ending 9 pm
Handset suffix
-T, -S or -P (-G for government)
Chosen per
Content template, under TCCCPR 2018

05Example: A Jaipur handicrafts store sorts its SMS

A Jaipur handicrafts store audits its SMS templates before Diwali. Login OTPs and order, dispatch and delivery updates are service implicit: no promotional words, delivered to every customer at any hour. The Diwali sale announcement is promotional: it goes from the promotional header, only in daytime hours, and skips customers who have opted out through DND. One back-in-stock message also offered 10% off today and had been filed as service implicit; the team moves it to a promotional template, because the discount makes it marketing whatever triggered it.

06 · Common mistakes, and the fix

Common mistakes with a DLT message category

  • Filing OTPs as promotional

    Promotional traffic stops at night and skips DND numbers, so logins fail. Non-bank OTPs belong in service implicit, and a bank's transaction OTPs in transactional.

  • Slipping offers into service messages

    A discount line in an order update makes it promotional. Keep cross-selling out of service templates, or register a separate promotional template for it.

  • Confusing DLT and WhatsApp categories

    An SMS service-implicit template is not a WhatsApp utility template. Classify each under its own rules and never assume one approval carries over to the other channel.

  • Sending service-explicit messages without recorded consent

    Consent held in your CRM is not enough: scrubbing checks consent recorded on DLT. Register consent templates and use digital consent acquisition.

  • Ignoring the promotional window

    A promotional campaign scheduled for 9:30 pm will not be delivered that evening. Schedule promotional sends well inside daytime hours.

07 · Tips from the bench

Best practices for a DLT message category

  • Note each template's category rule in its internal description so reviewers can check it quickly.
  • Audit templates before festive campaigns, when offers creep into service messages.
  • Keep OTP templates to the code, its validity and the brand name, nothing more.

08DLT Message Category FAQs

Which DLT category should I use for OTP SMS?+
Use transactional only for a bank's OTP that completes the customer's transaction; other OTPs, such as app logins, go under service implicit. Both reach DND numbers at any hour.
What is the difference between service implicit and service explicit?+
Service implicit messages follow from the customer's own action or relationship and need no explicit consent. Service explicit messages are sent only because the customer gave explicit consent that is recorded on DLT, and scrubbing checks for it.
At what time can promotional SMS be sent in India?+
Only during daytime hours: scrubbing delivers promotional traffic in a window that closes at 9 pm, with the opening time set by operator rules. Schedule campaigns well inside that window.
Are DLT categories the same as WhatsApp template categories?+
No. DLT categories set SMS delivery rules on Indian networks, while WhatsApp's marketing, utility and authentication categories set Meta's template review and per-message price.

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