WhatsApp vs SMS for business: cost, reach and which to use when

Indian businesses used to send everything by SMS: offers, reminders, OTPs. Today most customers live on WhatsApp. That doesn’t make SMS useless; it means each channel has a job. Here is a straight comparison.

Quick comparison

	WhatsApp (Business Platform)	SMS (commercial, India)
Cost per business-started message	₹0.12 (utility) to ₹0.86 (marketing), approx., 2026, before GST	Usually lower per message in bulk
Customer-started conversations	Your replies inside 24 hours are service messages, cheap or free	Each reply still costs
Can the customer reply?	Yes, it is a chat	Usually not from a short sender ID
Rich media	Photos, PDFs, video, location, buttons	Text only, 160 characters per part
Sender identity	Your business name, logo, profile	A 6-character sender ID
Approval	Meta business verification, template review	TRAI DLT registration of entity, headers and templates
Works without internet	No	Yes
Reach	Most smartphone users in India	Every mobile phone

Where WhatsApp wins

• Sales conversations. Leads ask questions; WhatsApp lets them, and lets you answer with a photo, a price list or a location pin.
• Follow-ups. A friendly message from a recognisable business gets a reply. A promotional SMS gets ignored. See follow-up templates.
• Quotes and documents. Send the PDF where the conversation is happening.
• Reminders with buttons. “Reply 1 to confirm” cuts no-shows.
• Trust. Your name and logo, not “VM-ABCDEF”.

Where SMS still wins

• OTPs and critical alerts where delivery to every phone matters more than replies.
• People without WhatsApp or data, including some older customers and rural areas.
• Very cheap one-way blasts where you don’t expect replies.
• Fallback: if a WhatsApp message fails, SMS can still reach the person.

The cost question, properly

Comparing price per message misses the point. Compare cost per reply and cost per sale.

Example: 1,000 past enquiries, re-engagement offer.

• SMS: cheap per message, a handful of people call back, and you cannot tell who read it.
• WhatsApp marketing template: about ₹860 + GST in Meta fees. If even 5% reply, that is 50 two-way conversations, and your replies within 24 hours cost little more.

For sales, the channel that starts conversations usually costs less per sale. Full pricing: WhatsApp Business API pricing in India.

Rules on both channels

• SMS: register on a DLT platform, register sender headers and templates, follow TRAI’s preferences and timing rules for promotional SMS.
• WhatsApp: get opt-in, use approved templates to start conversations, honour STOP, and keep your quality rating healthy.

Spam on either channel hurts you. On WhatsApp it can also cost you your number: see why WhatsApp numbers get banned.

A simple split for most small businesses

• WhatsApp: first replies to enquiries, qualifying, quotes, follow-ups, appointment and visit reminders, re-engagement.
• SMS: OTPs, payment and security alerts, and a fallback for people not on WhatsApp.
• Calls: hot leads, negotiation and closing.

How OakDeal fits

OakDeal runs the WhatsApp side through Meta’s official platform: AI first replies in seconds, Hot, Warm and Cold lead scoring, and follow-ups on schedule. Calls and SMS go out from your own phone with one tap, and OakDeal asks how the call went when you come back, so every touch is logged against the lead.