WhatsApp vs. SMS: Why Conversational Costs Still Favour WhatsApp
From July 1, 2025, WhatsApp Business transitioned from a flat conversation window fee to a per-marketing message pricing model, aiming to “simplify costs, align with industry standards, and enhance the quality of messaging experiences for both businesses and customers.”
The way Meta charges WhatsApp Business traffic remains fundamentally different and still significantly more cost-efficient than SMS. Instead of metering every character or segment, WhatsApp now charges per delivered marketing message, with service replies within a customer-initiated 24-hour window still free.
New Cost Maths: Real Conversations, Real Savings
Consider a typical customer interaction in the UK:
- A brand starts the conversation with a marketing template → £0.04
- The customer replies → free for the business.
- The brand responds with a service message within 24 hours → free.
- Additional marketing follow-ups -> £0.04
Meanwhile, the same back-and-forth on SMS:
- Each outbound text → £0.04 per message
- Each customer reply → £0.007 incoming fee.
- 3 outbound + 3 inbound = ~£0.1, and that’s just for plain text.
Even with WhatsApp’s new per-marketing message pricing, 3 routine back-and-forths still costs >3x more on SMS.
More Than Just Text: Richer Media at Lower Cost
Unlike SMS, WhatsApp gives you unlimited potential for rich media at no extra cost. High-resolution product photos, clickable product catalogs, interactive reply buttons, payment links, and even voice notes all help convert chat into sales with zero surprise charges. This creates a customer experience that’s not only more engaging but also more efficient for businesses.
A Pricing Model That Rewards Real Conversations
The biggest benefit? WhatsApp’s model encourages real, conversational engagement instead of pushing brands to cram everything into a single message. With service replies still free within the 24-hour window, your team can answer questions, clarify details, and build trust without worrying about ballooning costs. That’s something no SMS gateway can match.
Why Merx Makes WhatsApp Work for Your Business
WhatsApp is powerful, but on its own it’s just a channel. Merx turns it into a true growth engine. We don’t just connect you to WhatsApp; we optimise every message for maximum impact, personalised, timely, and designed to convert.
No code. No guesswork. Just intuitive tools that let you build rich, interactive customer journeys that connect seamlessly with your CRM, payment gateways, and support workflows. And we give you the analytics that matter: from open rates to replies to revenue, so you can prove the ROI of every conversation.
