Guides for messaging in India
Practical, India-specific guides on SMS, OTP, WhatsApp, and voice — DLT, routing, pricing, and the decisions that actually matter — from the people who run the platform.
- Voice automation · 23 June 2026
The 1600 number mandate: what regulated callers in India need to know
TRAI's 1600 numbering series for banks, NBFCs, insurers and SEBI-registered firms: who has to move, the phased timeline, and why a recognised caller ID lifts answer rates.
- Verification · 10 June 2026
WhatsApp OTP vs SMS OTP: choosing a verification channel in India
SMS reaches every handset; WhatsApp authentication templates add one-tap codes and a different cost model. How the two compare, and when to sequence both.
- Rich messaging · 10 June 2026
WhatsApp opt-in rules: consent that keeps your broadcasts landing
Meta requires opt-in before a business messages a customer on WhatsApp. What counts as consent, how Indian businesses collect it, and why it protects deliverability.
- Rich messaging · 10 June 2026
WhatsApp Business app vs API: when the free app stops being enough
The WhatsApp Business app suits one number and one pair of hands. What changes with the API — broadcasts, team inboxes, automation — and the signs it's time to move.
- Voice · 10 June 2026
Writing a voice broadcast script people stay on the line for
A voice broadcast earns or loses attention in the first seconds. How to structure the script — identity first, one message, one keypress action — and record it well.
- Voice automation · 10 June 2026
Toll-free vs virtual numbers: which number should your business publish?
1800 toll-free numbers and virtual numbers do different jobs — who pays for the call, what callers read into the number, and how routing and tracking differ.
- SMS · 10 June 2026
SMS character limits: GSM-7, Unicode, and why one symbol can triple your bill
How SMS encoding actually works — 160 characters in GSM-7, 70 in Unicode, 153 or 67 once a message splits — and how to keep your segment counts honest.
- Rich messaging · 10 June 2026
RCS vs SMS: what actually changes, and what doesn't
RCS adds a verified sender, media, and buttons to carrier messaging; SMS keeps universal reach. How the two differ in India, and why campaigns usually need both.
- Voice · 10 June 2026
Promotional calls in India: the TRAI rules to know before you dial
Outbound voice campaigns in India run under TRAI's telemarketing rules — DND scrubbing, registered senders, calling windows, consent. What compliant dialing looks like.
- Verification · 10 June 2026
OTP not delivered? A troubleshooting checklist for Indian SMS routes
Where SMS OTPs actually fail in India — template scrubbing, wrong header categories, handset quirks — and how to instrument the flow so you find out before users do.
- Voice automation · 10 June 2026
IVR menu design: getting callers to an answer without the maze
Callers don't want your menu — they want an outcome. How to design IVR menus that resolve calls: language first, shallow trees, plain prompts, and always a way out.
- SMS · 10 June 2026
Why DLT templates get rejected, and how to write ones that pass
The common reasons SMS content templates fail DLT review in India — category mismatches, variable mistakes, header conflicts — and a drafting process that clears it.
- SMS · 9 June 2026
Transactional vs promotional SMS in India: which route to use
Transactional, service, and promotional SMS in India follow different DLT rules, hours, and headers. Here's how to tell them apart and route each one correctly.
- SMS · 8 June 2026
How to choose a bulk SMS provider in India: a checklist
Price is only one factor. A practical checklist for choosing a bulk SMS provider in India — DLT, deliverability, channels, support, and the questions to ask.
- Verification · 7 June 2026
SMS OTP best practices: expiry, rate limits, and auto-read
How to build a secure, low-friction SMS OTP flow in India — code length, expiry, attempt caps, voice fallback, and Android auto-read — without storing a single code.