TRAI DLT category guide

The 4 DLT categories: Transactional, Service Implicit, Service Explicit, Promotional

TRAI defines four distinct DLT template categories. Each has different approval timelines, operator scrubbing rules, and use-case constraints. Understanding the boundary between them is essential; a misclassified template wastes weeks and damages your sender reputation.

Transactional templates deliver time-sensitive, user-initiated account credentials or confirmations. OTPs, PINs, password resets, booking confirmations, payment notifications, and account lockdown alerts belong here. The key criterion: the user explicitly triggered an action that generated the message. Transactional messages are exempt from most consent checks in India and have the fastest approval (1–2 hours). They enjoy the highest delivery priority because operators recognize them as critical to user experience.

Service Implicit templates communicate routine service updates that the user has implicitly consented to by signing up for your service. Billing notifications, delivery status updates, appointment reminders, and subscription expiry alerts fit this category. The user did not opt in to each specific message, but they agreed to receive service-related information as part of the relationship. Approval typically takes 2–8 hours. Operators may apply slightly stricter content filtering than Transactional, but delivery is still reliable.

Service Explicit templates require the user to have actively consented to receive that specific category of message. Promotional offers tied to a service, loyalty program updates, or feature announcements belong here. The distinction from Service Implicit is active, documented consent — a checkbox or explicit request. Approval takes 4–24 hours and operators maintain tighter scrubbing rules. You must also prove consent records to the operator upon request.

Promotional templates deliver unsolicited marketing messages. Offers, discounts, event announcements, or generic brand communications fall here. Promotional templates have the slowest approval (2–3 business days), strictest content filtering, and lowest delivery priority. Many operators rate-limit promotional traffic or quarantine it into a separate queue. TRAI also imposes stricter consent and unsubscribe requirements for Promotional messages. Unless your use case genuinely involves cold outreach or broad-audience campaigns, avoid Promotional; it often underperforms and frustrates users.

Category → scrubbing behavior mapping

TRAI operators (Airtel, Jio, Vodafone) deploy content-filtering rules that vary by template category. Understanding this mapping helps you craft templates that survive scrubbing and maintain delivery rates.

Transactional scrubbing is minimal. Operators whitelist keywords like "OTP," "pin," "confirm," "verify," and allow URLs, timestamps, and numeric codes. The rationale: these messages are user-triggered and low-risk. A template with "Your OTP is 123456" passes unchallenged. Transactional templates rarely trip content filters unless they include unrelated promotional language (e.g., "Your OTP is 123456. Download our app now!" would be rejected or degraded).

Service Implicit scrubbing is moderate. Operators accept service-related keywords ("order," "shipment," "appointment," "subscription," "billing") but watch for hidden promotions. A message like "Your shipment will arrive by 3 PM" is fine; "Your shipment will arrive by 3 PM — buy more now!" is not. Operators also check that the sender is clearly identified and that no unverified third-party links are embedded. Avoid shorteners (bit.ly, tinyurl) in Service Implicit templates; operators distrust them and may drop the message.

Service Explicit scrubbing is strict. Operators demand explicit brand identification in the message body, clear opt-in/opt-out language, and proof of user consent in your DLT records. A template like "{{BRAND}} offers 20% off your next order" is rejected because {{BRAND}} is a variable and the brand name is not hardcoded. Rewrite as "Acme Corp offers 20% off your next order. Reply STOP to unsubscribe." Operators also flag templates that mimic Transactional urgency (e.g., using "urgent," "act now," or urgency-driven language) in Service Explicit category, as this blurs the boundary and tricks users.

Promotional scrubbing is heaviest. Operators strip or block messages containing clickbait language ("Click here now," "Limited time," "Don't miss out"), unverified URLs, misleading sender names, or any hint of account manipulation. Promotional templates also get rate-limited per recipient per day — you cannot send more than one Promotional message per user per 24 hours on most operators. This rate limit is rarely disclosed but widely enforced via silent drops.

Why OTP traffic must be Transactional (and why senders get this wrong)

One-time passwords are the most commonly miscategorized message type. Senders often register OTP templates as Service Implicit or Service Explicit to "cast a wider net" or because they misunderstand the DLT rules. This is a critical mistake.

TRAI and Indian operators have mandated that all OTP, PIN, and password-reset messages be registered as Transactional. This is not a recommendation — it is a firm classification rule. When an operator's inbound content filter sees a message matching OTP patterns (e.g., "Your OTP is 123456"), it checks the template category. If the category is not Transactional, the operator scrubs the message (silent drop). The user never sees the code, the login fails, and your application appears broken.

Why do senders get this wrong? Several reasons. First, misunderstanding of "Transactional" — some teams assume it means "only for transactions" and categorize password resets as Service Implicit, thinking resets are not transactional business events. Second, template reuse: a team has a single template library and tries to use one OTP template across all categories for simplicity, registering it once as Service Implicit. Third, approval speed: a team hopes to speed up Service Explicit approval by bundling OTP with promotional offers, creating a hybrid template. None of these approaches work. Operators will reject the template or drop the messages.

The fix is simple: create a dedicated Transactional template for OTP. The template text should be minimal and contain only the OTP code, recipient identifier, and optional branding. For example:

# Transactional OTP Template (approved format)
Your smsroute OTP is 456789. Valid for 10 minutes. Do not share.
    

Do not append promotional text, links, or secondary calls to action. If you need to send a promotional offer alongside authentication, send two separate messages: one Transactional OTP and one Service Explicit offer. This approach also respects user attention and reduces friction.

Template registration: the Airtel/Jio/Vi portals

India's major telecom operators each maintain a separate DLT portal where you must register your templates. These portals are your gateway to sending SMS to India. There is no unified national DLT registry; each operator's approval is independent.

Airtel DLT Portal (sms.airtel.com) is widely used and relatively straightforward. You log in with your Principal Entity (PE) credentials, create a new template, assign it a category, provide the message content, and submit. Airtel typically approves Transactional templates within 1–2 hours. The interface is Hindi and English. Rejection reasons are often vague (e.g., "Content not suitable"), requiring trial-and-error to diagnose the real issue.

Jio DLT Portal (jiotrust.jio.com) requires a JIOTRUST ID linked to your PE license. Jio's approval workflow is more stringent; they perform manual review on most Service Explicit and all Promotional templates. Approval times are 2–24 hours. Jio also requires that you upload proof of user consent (a signed opt-in form or screenshot of checkbox) for Service Explicit and Promotional templates. This is a significant friction point; if your consent records are incomplete, expect rejection.

Vi DLT Portal (trueconnect.vi.com) is the newest and has the least consistent rules. Vi uses a third-party provider (TrueConnect) to manage their DLT registry. Approval times are 4–48 hours. Vi also imposes stricter keyword filtering; some benign words (e.g., "limited," "exclusive") are flagged automatically. Vi is also the most likely operator to silently drop messages without notifying you of a rejection.

For national reach within India, you must register your template with all three operators independently. A template approved by Airtel may be rejected by Jio or Vi due to different keyword lists and review standards. smsroute handles multi-operator template submission and tracking on your behalf, abstracting the portal complexity. However, you retain login access to each operator's portal for independent verification and resubmission if needed.

Common rejection reasons (generic wording, missing brand name, wrong variables)

Rejections are common on first submission. Understanding the hidden reasons behind cryptic rejection messages saves weeks of iteration.

Generic wording is a leading cause of rejection, especially in Service Explicit and Promotional categories. Operators flag templates that could apply to any service, with no specific identifier. A template reading "Your order is ready for pickup" is rejected because it does not name the business. Rewrite as "Acme Corp: Your order #12345 is ready for pickup at the downtown store." Operators want to see proper nouns, specific order/transaction IDs, and clear sender identification. This also helps users recognize legitimate messages and reduces phishing risk.

Missing or variabilized brand name is another major failure mode. Operators reject templates in which the sender brand is a variable placeholder (e.g., {{BRAND_NAME}}, {{COMPANY}}, {{SERVICE_PROVIDER}}). TRAI requires that the brand name be hardcoded and visible to TRAI reviewers at template registration time. The reason: TRAI is verifying that the template content matches the registered principal entity. If the brand is a variable, TRAI cannot verify consistency and denies approval. Always hardcode your brand name in the template body, even if you send similar messages on behalf of multiple customers. Create separate templates for each customer, each with the customer's hardcoded brand.

Incorrect variable syntax will trigger rejection on most portals. TRAI uses specific variable delimiters. The correct syntax is double curly braces with uppercase underscore-separated names: {{OTP_CODE}}, {{ORDER_ID}}, {{RECIPIENT_NAME}}. Avoid Handlebars syntax ({{variable}}), Jinja ({% variable %}), or dollar-sign notation ($variable). Test your template syntax on the portal's preview tool before final submission. A misplaced bracket can cause silent drops even if the template is initially approved.

Unverified URLs or shorteners cause rejection in Service Implicit, Service Explicit, and Promotional categories. Operators distrust shortened URLs (bit.ly, tinyurl, etc.) because they hide the destination and are commonly used in phishing. Always use the full, explicit URL from your own domain. For example, "Click here to confirm" with a tinyurl is rejected. "Confirm your email: https://acme.com/confirm?token=ABC123" is acceptable. URLs must also be HTTPS; HTTP-only links are flagged as insecure.

Unsubscribe/opt-out language is mandatory for Service Explicit and Promotional. Templates missing an opt-out instruction ("Reply STOP to unsubscribe" or "Text STOP to exit") are rejected on these categories. Transactional and Service Implicit templates do not require opt-out language by TRAI rules, though many operators recommend it for good practice. Ensure your opt-out language is clear and occupies fewer than 30 characters so it does not push the overall message over the SMS single-segment boundary.

Frequently asked questions

What happens if I register an OTP template as Promotional?

The template will likely be rejected during TRAI approval, or if approved, the SMS will be silently dropped by the operator. TRAI mandates that one-time passwords must be registered as Transactional only. Operators enforce this rule at send-time, scrubbing any OTP-pattern messages sent under a Promotional or Service Explicit category. Silent drops mean no bounce notification — the message simply vanishes, and your user sees no code.

Can I use the same template across multiple DLT categories?

No. Each template must be registered under exactly one DLT category. If you need to send the same message content as both transactional and promotional, you must create two separate template registrations — one in Transactional, one in Promotional — and track them independently in your TRAI DLT account.

Do I need a Principal Entity (PE) license to register DLT templates?

Yes. TRAI requires that all DLT registrations be linked to a valid Principal Entity (PE) license issued by TRAI. Your PE license is your organization's unique identifier in the DLT system. If you operate without a PE license, operators will reject your templates and block your sender ID. Obtaining a PE license involves KYC and typically takes 7–10 business days.

Why is my Service Explicit template being rejected?

Service Explicit templates often fail because they are missing the service provider brand name or contain generic placeholders. TRAI requires clear identification of the entity delivering the service. Common issues include using only variable names (e.g., {{SERVICE_NAME}}) without a hardcoded company name, using vague language like "Your service is ready," or failing to include opt-in/opt-out instructions. Re-register with your actual brand name visible in the message body.

Which DLT portal should I use — Airtel, Jio, or Vi?

You must register templates with the major operator whose network you intend to use. Airtel, Jio (Reliance), and Vi (Vodafone Idea) each maintain separate DLT portals. For reach across India, register your template with all three. Each portal has slightly different approval timelines and UI. smsroute handles template submission on your behalf if you provide the template details — you retain control via your TRAI DLT login.

How long does DLT template approval take?

Standard Transactional templates (OTP, PIN, password reset) typically approve within 1–2 hours. Service Implicit and Service Explicit categories may take 2–24 hours depending on manual review. Promotional templates are slowest and may require 2–3 business days. Rejection resets the clock: you resubmit a corrected template and wait again. To minimize delay, ensure brand name is hardcoded, variable syntax is correct, and the message purpose aligns exactly with the registered category.