What does DLT error code 602 (ENTITY_INACTIVE) mean and how do I fix it?

Your Principal Entity (PE) registration is currently blocked, expired, or inactive in the telecom database. Fix: Access the DLT portal where your PE was registered (Jio, Airtel, Vodafone Idea, BSNL) and check for an expired annual subscription or account suspension.

What does DLT error code 610 (TELEMARKETER_NOT_REGISTERED) mean and how do I fix it?

There is no entry for your Telemarketer ID (TMID) on the platform. Fix: Send an email to our support team to get your TM ID registered/verified.

What does DLT error code 614 (CLI Mismatch With Template) mean and how do I fix it?

The Sender ID (Header) or Template ID used in your SMS doesn't match — the header isn't linked to that template on your DLT portal. Fix: Open your DLT panel and ensure you're using the correct 6-character Sender ID (Header) assigned to that specific Content Template ID.

What does DLT error code 615 (Template Or Header Invalid) mean and how do I fix it?

The Template ID or Header (Sender ID) in your SMS request doesn't exactly match, or isn't correctly linked, on your DLT portal. Fix: Log in to your DLT portal (Vilpower, Jio, PingConnect), search your specific Template ID, and ensure your exact Header is actively mapped to it.

What does DLT error code 621 (HEADER_INACTIVE) mean and how do I fix it?

Your registered Sender ID (Header) exists on the DLT platform but is currently blocked from sending messages. Fix: Log in to your telecom operator's DLT portal (Jio TrueConnect, Vodafone/Vi, Airtel) and check the Header status.

What does DLT error code 622 (HEADER_BLACKLISTED) mean and how do I fix it?

Your Sender ID (Header) has been blocked or suspended across telecom networks. Fix: Log in to your DLT portal → Sender ID section, check the status. If blocked, get a new Sender ID approved or contact your DLT provider.

What does DLT error code 631 (TEMPLATE_INACTIVE) mean and how do I fix it?

Your message is blocked because the exact SMS template you're using has not been approved or is currently deactivated. Fix: Log in to your DLT portal and confirm the Template ID is marked Approved / Active.

What does DLT error code 635 (TEMPLATE_VARIABLE_EXCEEDED_MAX_LENGTH) mean and how do I fix it?

The data inside a template variable ({#var#}) exceeds the DLT platform's cap of 30 characters per variable. Fix: Ensure the dynamic data (name, URL, ID, etc.) stays under 30 characters for each variable.

What does DLT error code 642 (CTA_NOT_WHITELISTED) mean and how do I fix it?

The URL included in your SMS message hasn't been whitelisted on the DLT platform, which TRAI regulation requires for delivery. Fix: Open your DLT panel and whitelist your URL, or send a URL that matches your already-whitelisted CTA.

What does DLT error code 650 (PREFERENCE_NOT_MATCHED) mean and how do I fix it?

Your promotional or service-explicit SMS was blocked because the recipient is registered on the DND (Do Not Disturb) list. Fix: Only send to NON-DND numbers, between 10 AM and 9 PM, or get your template approved under Service Implicit.

What does DLT error code 660 (CONSENT_FAILED) mean and how do I fix it?

General error code for consent-related rejection. Fix: Verify recipient consent status and template category before resending.

What does DLT error code 670 (SCRUBBING_FAILED) mean and how do I fix it?

General error code covering any DLT scrubbing exception. Fix: Retry the send; if it persists, contact support with the message ID.

What does DLT error code 805 (Template Blacklisted / Inactive) mean and how do I fix it?

Template is blacklisted, not verified, or inactive on the DLT platform. Fix: Check the status on your DLT portal. If suspended, draft and submit a new template with compliant phrasing.

What does DLT error code 813 (Hash Does Not Match With PE-TM Chain) mean and how do I fix it?

The PE-TM hash is invalid because one of the telemarketers in the chain is inactive. Fix: Add our Telemarketer ID (1302157243747322354) in the PE-TM chain option and update us for final approval.

What is bulk SMS and how does it work?

Our bulk SMS platform enables businesses to send Transactional SMS, Promotional SMS, OTP SMS, Voice, and WhatsApp messages. We offer API integration, DLT compliance, and real-time delivery reports.

Can I send SMS to DND numbers?

Yes, but only transactional or service-based messages can be sent to DND numbers. Promotional messages are blocked for users registered under DND preferences.

What is a transactional SMS (Service Implicit) in India?

Transactional SMS refers to messages sent to customers containing important information such as OTPs, alerts, or order confirmations. These messages are delivered even to DND numbers and are regulated under TRAI guidelines.

How do you protect my data and privacy?

We use SSL encryption, secure APIs, and follow TRAI's DLT protocols to ensure your data and messages are protected during transmission.

What is promotional SMS (Service Explicit) and when can it be sent?

Promotional SMS is used for marketing offers, discounts, and advertisements. In India, promotional messages can only be sent to non-DND numbers and within permitted time windows, typically 10 AM to 9 PM as per TRAI regulations.

Is bulk SMS secure for sending OTPs?

Yes, bulk SMS is widely used for OTP delivery due to its speed and reliability. However, it should be used with secure APIs and proper authentication mechanisms.

What is DLT registration and why is it required?

DLT (Distributed Ledger Technology) registration is a mandatory process introduced by TRAI to prevent spam SMS. Businesses must register their sender ID, templates, and headers on a DLT platform before sending SMS in India.

How much does bulk SMS cost in India?

Bulk SMS pricing in India typically ranges from ₹0.10 to ₹0.25 per SMS, depending on volume slabs.

How can I send SMS using API?

You can send SMS via API by integrating your system with an SMS gateway provider. Most providers offer REST APIs where you send parameters like mobile numbers, message content, and sender ID to trigger SMS delivery.

What is the difference between Service Implicit SMS and Service Explicit SMS?

Service Implicit SMS is used for important alerts and is delivered to all users, including DND numbers. Service Explicit SMS is used for marketing and is restricted to non-DND users and specific time windows.

Home / Support / DLT Error Codes & Solutions

TRAI DLT & SMPP Troubleshooting

DLT Error Codes & Solutions — Complete Reference

Q: What does DLT error code 603 (ENTITY_BLACKLISTED) mean and how do I fix it?

Your Entity is blacklisted across all DLT platforms. Fix: Email your primary DLT operator (Jio, Airtel, Videocon, or Vodafone Idea) to dispute the block. You must submit a formal appeal explaining how you'll prevent future spam.

Every TRAI DLT and SMPP rejection code your Bulk SMS, OTP or Transactional messages can return — decoded in plain English with the exact fix, mapped to your operator's DLT portal.

106+Error codes decoded

10Failure categories

14+ yrsDLT compliance experience

24x7Support on call & email

TLV / SMPP Integration 3 codes

What it means: Template not enabled in the application — your integration is missing required optional parameters.

How to fix it

Your SMS API integration relies on SMPP (Short Message Peer-to-Peer). You must explicitly pass the PE ID (tag 0x1400) and Template ID (tag 0x1401) as optional TLV (Type-Length-Value) parameters in every submit_sm request.

What it means: Template not enabled in the application — the PE ID TLV is missing from the request.

How to fix it

Your SMPP integration must explicitly pass the PE ID (0x1400) and Template ID (0x1401) as optional TLV parameters in every submit_sm request.

What it means: Template not enabled in the application — the Template ID TLV is missing from the request.

How to fix it

Your SMPP integration must explicitly pass the PE ID (0x1400) and Template ID (0x1401) as optional TLV parameters in every submit_sm request.

Principal Entity (PE) Errors 15 codes

What it means: The DLT platform does not recognise the Principal Entity (PE) ID submitted with your message.

How to fix it

Log in to your TRAI DLT portal (Airtel, Jio TrueConnect, Vodafone Idea, or BSNL) and check your registered Principal Entity profile, then map the correct ID.

Watch fix video

What it means: The DLT platform does not recognise the Principal Entity (PE) ID submitted with your message.

How to fix it

Log in to your TRAI DLT portal (Airtel, Jio TrueConnect, Vodafone Idea, or BSNL) and check your registered Principal Entity profile, then map the correct ID.

Watch fix video

What it means: Your Principal Entity (PE) registration is currently blocked, expired, or inactive in the telecom database.

How to fix it

Access the DLT portal where your PE was registered (Jio, Airtel, Vodafone Idea, BSNL) and check for an expired annual subscription or account suspension.

What it means: Your Entity is blacklisted across all DLT platforms.

How to fix it

Email your primary DLT operator (Jio, Airtel, Videocon, or Vodafone Idea) to dispute the block. You must submit a formal appeal explaining how you'll prevent future spam.

What it means: You are submitting an incorrect or invalid Principal Entity ID (PE ID).

How to fix it

Log in to your DLT portal (Airtel, Jio TrueConnect, Vodafone Idea, or BSNL), check your registered PE profile, and re-map it correctly.

Watch fix video

What it means: Your Principal Entity (PE) ID is not mapped with a Telemarketer (TM) ID.

How to fix it

Contact our support team to re-link/bind your PE ID to a Telemarketer ID on the DLT platform. Our TM ID: 1302157243747322354.

Watch fix video

What it means: Your business's Principal Entity (PE) ID has been blocked from sending messages.

How to fix it

Log in to your registered DLT portal (Jio TrueConnect, Airtel SmartPing, or Videocon VILPOWER) to check the exact status of your PE ID, then contact your DLT provider.

What it means: Your Principal Entity is inactive or not registered specifically with Airtel's DLT chain.

How to fix it

What it means: You are submitting an incorrect or invalid Principal Entity ID (PE ID).

How to fix it

Watch fix video

What it means: You are submitting an incorrect or invalid Principal Entity ID (PE ID).

How to fix it

Watch fix video

What it means: The Principal Entity is inactive or disabled — possible suspension, temporary deactivation, or restriction.

How to fix it

What it means: The requested Principal Entity has been blocklisted for a policy violation, non-compliance, or suspicious activity.

How to fix it

What it means: The Principal Entity ID is in an invalid format or does not exist on the DLT provider.

How to fix it

What it means: This Principal Entity is not allowed for the mapped Telemarketer (TM).

How to fix it

Contact support to re-check the PE-TM linkage on the DLT platform.

What it means: You are submitting an incorrect or invalid Principal Entity ID (PE ID).

How to fix it

Watch fix video

Telemarketer (TM) Errors 10 codes

What it means: There is no entry for your Telemarketer ID (TMID) on the platform.

How to fix it

Send an email to our support team to get your TM ID registered/verified.

What it means: Telemarketer is inactive on the platform (e.g. “Invalid entity id provided” / “Invalid Header id for this Entity”).

How to fix it

Send an email to our support team.

What it means: Telemarketer is blacklisted on all platforms, or an invalid CLI was used.

How to fix it

Send an email to our support team.

What it means: Your SMS failed because the Template ID passed in the SMS is invalid.

How to fix it

Log in to your DLT portal (VilPower, Jio, Smartping) to copy the exact 19-digit numerical Template ID and map it in the SMS panel.

Watch fix video

What it means: The system rejects the message because it cannot match your Telemarketer (TM) registration against the PE-TM chain.

How to fix it

Send an email to our support team.

What it means: The system rejects the message because it cannot match your Telemarketer (TM) registration against the PE-TM chain.

How to fix it

Send an email to our support team.

What it means: TRAI or the telecom operator has blocked your TM ID.

How to fix it

Send an email to our support team.

What it means: There is no entry for your TMID on the platform.

How to fix it

Send an email to our support team.

What it means: Telemarketer is inactive on the platform (e.g. “Invalid entity id provided” / “Invalid Header id for this Entity”).

How to fix it

Send an email to our support team.

What it means: TRAI or the telecom operator has blocked your TM ID.

How to fix it

Send an email to our support team.

Header / Sender ID Errors 19 codes

What it means: The Sender ID (Header) or Template ID used in your SMS doesn't match — the header isn't linked to that template on your DLT portal.

How to fix it

Open your DLT panel and ensure you're using the correct 6-character Sender ID (Header) assigned to that specific Content Template ID.

What it means: The Template ID or Header (Sender ID) in your SMS request doesn't exactly match, or isn't correctly linked, on your DLT portal.

How to fix it

Log in to your DLT portal (Vilpower, Jio, PingConnect), search your specific Template ID, and ensure your exact Header is actively mapped to it.

What it means: The Sender ID (Header) used to send your bulk SMS is not registered on the DLT platform, or is wrong.

How to fix it

Log in to your DLT platform (Jio DLT or Vi DLT) → Header SMS section, verify the 6-character header shows Approved status, and map it correctly in the SMS panel.

Watch fix video

What it means: Your registered Sender ID (Header) exists on the DLT platform but is currently blocked from sending messages.

How to fix it

What it means: Your Sender ID (Header) has been blocked or suspended across telecom networks.

How to fix it

Log in to your DLT portal → Sender ID section, check the status. If blocked, get a new Sender ID approved or contact your DLT provider.

What it means: The Principal Entity ID (PE ID) you're passing doesn't match the Header (Sender ID).

How to fix it

Log in to your DLT portal (Pingconnect, Videocon, Airtel) → Approved Headers section. The Sender ID should be approved under your PE account.

What it means: Your requested Header has either expired (validity ended) or is reserved/restricted by the telecom operator.

How to fix it

What it means: The Sender ID (Header) you're using is not linked to the specific Template ID you submitted.

How to fix it

What it means: Your Sender ID (Header) has been blocked or suspended across telecom networks.

How to fix it

What it means: Your registered Sender ID (Header) exists on the DLT platform but is currently blocked from sending messages.

How to fix it

What it means: The PE ID you're passing doesn't match the Header (Sender ID).

How to fix it

What it means: Your registered Sender ID exists on the DLT platform but is blocked from sending messages.

How to fix it

Check Header status on your DLT portal. If active, re-map it in the SMS panel with proper details.

What it means: Your Sender ID (Header) has been blocked or suspended across telecom networks.

How to fix it

Check the Sender ID section on your DLT portal. If blacklisted, get a new header approved.

What it means: The PE ID you're passing doesn't match the Header (Sender ID).

How to fix it

What it means: The header is sitting in the operator's free pool and isn't actively mapped.

How to fix it

Contact your DLT provider to re-activate/allocate the header correctly.

What it means: The Sender ID (Header) you're using is not linked to the specific Template ID you submitted.

How to fix it

What it means: Your SMS Sender ID (Header) has been temporarily suspended because its registration validity has expired.

How to fix it

Open your DLT panel and verify again — no fresh approval is needed, just re-verification.

What it means: The header is suspended due to excessive usage that violates DLT regulations.

How to fix it

Review your sending practices, reduce volume if needed, and contact your DLT provider since the header status shows suspended.

What it means: The header has been suspended due to issues with the customer's DLT account.

How to fix it

Contact your DLT service provider or support team to resolve customer-specific DLT compliance concerns.

Template Errors 24 codes

What it means: The message category in your SMS request doesn't match the category approved for your template or header on the DLT portal.

How to fix it

Log in to your DLT portal (PingConnect, Jio DLT, Airtel DLT) and check the approved category (Promotional, Transactional, Service Implicit, or Service Explicit).

What it means: Your SMS cannot locate the specific message template you're trying to use.

How to fix it

Log in to your DLT portal, confirm the template is Active, and ensure you're passing the exact approved 19-digit Template ID. Re-map if wrong.

Watch fix video

What it means: Your message is blocked because the exact SMS template you're using has not been approved or is currently deactivated.

How to fix it

What it means: Your template is blacklisted on the DLT platform.

How to fix it

Check the status on your DLT portal. If suspended, draft and submit a new template with compliant phrasing.

What it means: The actual text of the SMS you're sending doesn't perfectly match your approved template.

How to fix it

Check character-by-character for differences between your actual text and the approved template.

What it means: The data inside a template variable ({#var#}) exceeds the DLT platform's cap of 30 characters per variable.

How to fix it

Ensure the dynamic data (name, URL, ID, etc.) stays under 30 characters for each variable.

What it means: A general error occurred while identifying the template.

How to fix it

Contact support with your Template ID for further diagnosis.

What it means: The DLT platform rejected your SMS because it received an incorrect Template ID format.

How to fix it

Check your DLT platform and ensure you're passing the correct, active Template_ID.

Watch fix video

What it means: Your Principal Entity (PE) is not linked or mapped correctly to the specific template.

How to fix it

Check that the Entity ID and Template ID on your DLT platform match; if not, re-map them.

Watch fix video

What it means: The actual text of the SMS you're sending doesn't perfectly match your approved template.

How to fix it

Check character-by-character for differences between your actual text and the approved template.

What it means: Template is blacklisted, not verified, or inactive on the DLT platform.

How to fix it

Check the status on your DLT portal. If suspended, draft and submit a new template with compliant phrasing.

What it means: The actual text of the SMS doesn't perfectly match your approved template.

How to fix it

Check character-by-character for differences between your actual text and the approved template.

What it means: Your message is blocked because the template hasn't been approved or is currently deactivated.

How to fix it

What it means: Your template is blacklisted on the DLT platform.

How to fix it

Check the status on your DLT portal. If suspended, submit a new template with compliant phrasing.

What it means: The actual text of the SMS doesn't perfectly match your approved template.

How to fix it

Check character-by-character for differences between your actual text and the approved template.

What it means: The data inside a template variable ({#var#}) exceeds the platform's 30-character cap.

How to fix it

Keep the dynamic data (name, URL, ID, etc.) under 30 characters per variable.

What it means: A general error occurred while identifying the template.

How to fix it

Contact support with your Template ID for further diagnosis.

What it means: The DLT platform rejected your SMS because it received an incorrect Template ID format.

How to fix it

Check the DLT platform and ensure you're passing the correct Template_ID. Re-map it in the SMS panel if wrong.

Watch fix video

What it means: Your Principal Entity (PE) is not linked or mapped correctly to the specific template.

How to fix it

Check that the Entity ID and Template ID on the DLT platform match; if not, re-map them.

Watch fix video

What it means: The message category in your SMS request doesn't match the category approved for your template or header.

How to fix it

What it means: The template has been suspended due to a validity problem with DLT compliance.

How to fix it

Open your DLT panel and verify the template again.

Watch fix video

What it means: The template is suspended due to excessive usage that violates DLT regulations.

How to fix it

Optimise your SMS templates or reduce frequency of use; contact your DLT provider or get a new template approved.

Watch fix video

What it means: The template has been suspended due to issues related to the customer's DLT compliance status.

How to fix it

Contact your DLT service provider to resolve customer-specific compliance concerns, or get a new template approved.

Watch fix video

What it means: The Sender ID (Header) or Template ID used in your SMS doesn't match — the header isn't linked to that template on your DLT portal.

How to fix it

Open your DLT panel and ensure you're using the correct 6-character Sender ID assigned to that specific Content Template.

PE-TM Chain / Hash Errors 9 codes

What it means: The status of the PE-TM hash is invalid, or the Telemarketer ID hasn't been added to the PE-TM chain option on the DLT portal.

How to fix it

Add our Telemarketer ID (1302157243747322354) in the PE-TM chain option, update us, then we'll approve it on our side.

Watch fix video

What it means: The PE-TM hash is invalid because one of the telemarketers in the chain is inactive.

How to fix it