SSiddiq.in
Official WhatsApp Business API

WhatsApp is cheap. Until nobody explained the 24-hour session window.

98% open rate. 45-second average reply time. And a billing model that can 10× if you get the template categories wrong. This page is what we wish someone had explained to us the first time.

Set up WhatsApp API
The one diagram every WhatsApp project needs

The 24-hour session window, visually.

User → You
Now — 24h
Inside the window: reply with anything, free. Free-form, media, buttons, lists. This is where deflection happens.
24h passed
Template only · charged per conversation
Outside the window: approved template messages only. Every template opens a new paid 24h conversation.
Utility
~₹0.30
Order updates, alerts, receipts
Authentication
~₹0.13
OTPs, login verification
Marketing
~₹0.85
Promotions, offers, campaigns
Service
Free
Any reply inside the 24h user-initiated window
Rates: India, Meta 2025 pricing. Approximate — varies by region and category.
Template approval, first try

Two templates. One approved in 6 hours. One rejected three times.

Rejected · marketing-as-utility
Hey! 🔥 Big weekend sale — up to 50% off. Reply STOP to opt out.
  • × Promotional in a utility template
  • × No transactional trigger
  • × Meta reads "sale" and re-categorises
Approved · utility, no debate
Hi {{1}}, your order #{{2}} is out for delivery today between {{3}} and {{4}}. Track: {{5}}
  • ✓ Clear transactional context
  • ✓ Variables for personalisation
  • ✓ No promotional language
BSP selection · honest matrix

The right provider changes by volume, not brand.

BSPVolume sweet spotShips fast whenSkip if
Interakt1k–50k msg/moD2C, Shopify plug-and-playYou need a rich REST API
AiSensy500–20k msg/moSMB budget, template library neededYou need custom flows
Gupshup50k+ msg/moEnterprise, multi-verticalYou want a slick UI
WATI1k–30k msg/moTeam inbox + CRM-liteYou'll build custom automations
TwilioAnyYou have engineers, want raw APIYou wanted a UI

WhatsApp FAQ

Nine times out of ten: promotional language in a utility template, or missing variables. 'Hi {{1}}, your order is on the way' passes. 'Buy now, 20% off!' as a utility does not. We write templates against Meta's category rules the first time so approvals ship in 24–48 hours.

Meta conversation pricing · 2025

Four conversation categories. Pricing rules that reshape your comms plan.

Meta charges per 24-hour conversation window, not per message. Category is set by intent — get this wrong and your monthly bill triples.

Utility
Order updates, reminders, receipts. Cheapest. Must be triggered by a user action or transaction. India: ~₹0.15 per conversation.
Authentication
OTPs only. Sub-second delivery required. Priced like utility. Fixed-format templates — no marketing sneaked in.
Marketing
Promotional, campaigns, product announcements. 3–5× the utility rate. Requires opt-in on record; opt-outs must be honoured within 24h.
Service (user-initiated)
Free 24-hour window after any inbound user message. Design flows so support conversations stay in-window — no free-to-paid drift.
Template approval lifecycle
Submit → Meta review (1–24h) → approved / rejected. Rejections cite policy line. Keep a library of pre-approved variants for campaigns.
Session windows
The 24h window resets on every inbound message. Outside window, only approved templates work. Track expiry per conversation in your DB.

Turn WhatsApp into a channel, not a bill.

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