What is DLT registration and is it mandatory in India?

DLT (Distributed Ledger Technology) registration is mandatory for all businesses sending bulk SMS in India as per TRAI regulations. Every business must register their entity, SMS headers and message templates on a DLT platform before sending bulk SMS.

How do I get WhatsApp Business API access in India?

To get WhatsApp Business API access in India, you need to apply through a Meta Business Solution Provider like Nesark. The process involves Meta Business Manager verification, phone number registration and business profile setup. Nesark provides zero setup fee WhatsApp API access.

What is the cost of bulk SMS in India?

Bulk SMS pricing in India typically ranges from ₹0.10 to ₹0.25 per SMS depending on volume, route type (transactional/promotional) and provider. Nesark offers competitive pricing starting from ₹0.12 per SMS with no hidden charges.

What is RCS messaging and how is it different from SMS?

RCS (Rich Communication Services) is the next generation of SMS that supports images, videos, carousels, action buttons and verified business branding. Unlike plain SMS, RCS provides a rich interactive experience within the native messaging app on Android phones.

How does bulk voice broadcasting work in India?

Bulk voice broadcasting (OBD calls) allows businesses to send automated pre-recorded voice messages to thousands of phone numbers simultaneously. You upload your audio message, upload the contact list and the system dials each number automatically. Nesark supports both text-to-speech and custom audio file uploads.

Resources | Bulk SMS, WhatsApp API, Voice, RCS & DLT Guides

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Bulk SMS

Top 10 Bulk SMS Marketing Tips for Indian Businesses in 2026

Proven strategies to maximize open rates, reduce opt-outs and drive conversions with bulk SMS campaigns in India.

8 min read · April 2026 Read →

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Bulk SMS

Transactional vs Promotional SMS — Complete Guide for India

Understand the difference between transactional and promotional SMS routes, DND rules, delivery timings and when to use each.

6 min read · March 2026 Read →

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Bulk SMS

Bulk SMS Pricing in India 2026 — What You Should Pay

Compare bulk SMS pricing plans across providers in India. Learn what affects per-SMS cost and how to choose the best value plan for your business.

5 min read · March 2026 Read →

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WhatsApp API

How to Get WhatsApp Business API Access in India — Step by Step

Complete guide to applying for WhatsApp Business API in India — documents needed, Meta verification, setup timeline and zero setup fee with Nesark.

10 min read · April 2026 Read →

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WhatsApp API

How to Get the Green Tick on WhatsApp Business — India Guide

The WhatsApp green tick builds massive customer trust. Learn Meta's official verification process and what your business needs to qualify.

7 min read · March 2026 Read →

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WhatsApp API

WhatsApp Chatbot vs Bulk SMS — Which is Better for Your Business?

An honest comparison of WhatsApp API chatbots and bulk SMS for Indian businesses — cost, reach, engagement and use cases explained.

9 min read · February 2026 Read →

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DLT

What is DLT Registration and Why is it Mandatory in India?

TRAI mandated DLT registration for all bulk SMS senders. Understand what it is, why it matters and the penalties for non-compliance.

6 min read · April 2026 Read →

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DLT

Documents Required for DLT Registration in India — Full Checklist

Complete list of documents needed for DLT entity registration, header approval and template submission — for individuals and businesses.

4 min read · March 2026 Read →

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DLT

TRAI New Rules May 2025 — What Changed for SMS Headers & Templates

TRAI's May 2025 update removed Service Explicit category and added mandatory suffixes (-P, -S, -T, -G) to all SMS headers. Here's what you need to update.

5 min read · May 2025 Read →

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RCS

What is RCS Messaging? The Future of Business SMS in India

RCS (Rich Communication Services) is the evolution of SMS — with images, carousels, action buttons and verified branding. Learn how it works in India.

7 min read · April 2026 Read →

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RCS

RCS vs SMS vs WhatsApp — Which Should Indian Businesses Use?

A detailed comparison of RCS, SMS and WhatsApp for Indian business messaging — covering reach, cost, features and the best use cases for each.

8 min read · March 2026 Read →

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RCS

How to Get Started with RCS Business Messaging in India

Step-by-step guide to onboarding your business on RCS in India — Google verification, brand setup and sending your first RCS campaign with Nesark.

6 min read · February 2026 Read →

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Voice Calls

What is Bulk Voice Broadcasting and How Does it Work in India?

Voice broadcasting lets you send automated pre-recorded calls to thousands of customers at once. Learn how OBD calls work and their best use cases in India.

6 min read · April 2026 Read →

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Voice Calls

TTS vs Pre-Recorded Audio for Voice Broadcasting — Which is Better?

Text-to-Speech vs uploading your own audio file for OBD campaigns — pros, cons and which works best for different industries in India.

5 min read · March 2026 Read →

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Voice Calls

10 Best Use Cases for Voice Broadcasting in Indian Businesses

From appointment reminders to loan alerts and election campaigns — discover how industries across India are using OBD voice calls to reach customers instantly.

7 min read · February 2026 Read →

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OTP SMS

How to Send OTP SMS in India — Complete Developer Guide 2026

Step-by-step guide to integrating OTP SMS in your app or website using Nesark's SMS API — with code samples in PHP, Python, Node.js and cURL.

10 min read · April 2026 Read →

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OTP SMS

Why OTP SMS Fails in India — Top Reasons & How to Fix Them

OTP delivery failures cost you customers. Learn the most common reasons OTP SMS fails in India — DLT issues, wrong routes, template errors — and how to fix them.

6 min read · March 2026 Read →

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OTP SMS

OTP SMS vs WhatsApp OTP — Which is More Reliable for Indian Apps?

Comparing OTP delivery via SMS and WhatsApp for Indian mobile apps — speed, cost, reliability and compliance considerations for 2026.

5 min read · February 2026 Read →

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Marketing

How to Build a Customer Engagement Strategy Using Omni-Channel Messaging

Combining SMS, WhatsApp, RCS and Voice into a unified customer engagement strategy — a practical guide for Indian SMBs and enterprises.

9 min read · April 2026 Read →

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Marketing

Festival SMS Marketing Calendar for Indian Businesses 2026

Plan your SMS campaigns around Diwali, Holi, Eid, New Year and 15+ major Indian festivals — with sample message templates included.

7 min read · March 2026 Read →

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Marketing

How E-Commerce Businesses in India Use SMS to Reduce Cart Abandonment

Case study: How leading Indian e-commerce brands use targeted SMS campaigns to recover abandoned carts, boost repeat purchases and improve customer retention.

6 min read · February 2026 Read →

Learn. Grow. Communicate Smarter.

Complete DLT Registration Guide for Indian Businesses 2026

📱 Bulk SMS

💬 WhatsApp Business API

📋 DLT Registration

✨ RCS Messaging

📞 Voice Broadcasting

🔑 OTP SMS

💡 Marketing Tips

Learn. Grow. Communicate Smarter.

Complete DLT Registration Guide for Indian Businesses 2026

📱 Bulk SMS

💬 WhatsApp Business API

📋 DLT Registration

✨ RCS Messaging

📞 Voice Broadcasting

🔑 OTP SMS

💡 Marketing Tips

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