WhatsApp Business app or the API? What changes for your system.

Two products, one name

The WhatsApp Business app is the one you download on a phone. Meta describes it as built with the small business owner in mind: a business profile, a product showcase, greetings and away messages. It is for one-to-one chats handled by a person.

The WhatsApp Business Platform is for software. Your system sends and receives messages through the Cloud API, so enquiries land in your CRM, staff reply from there, and reminders go out automatically. If you want to keep using the app on the same number, Meta’s “coexistence” setup allows it, with limits: group chats are not synchronised, and features such as calls, catalogues, orders, quick replies and labels are not supported through the API side.

Templates and the 24-hour window

When a customer messages you or calls you, a 24-hour timer called the customer service window starts. Each new message resets it. While it is open you can send ordinary free-form messages. When it is closed, Meta only allows template messages.

Templates are pre-written messages that you submit for review. Only approved templates can be sent. Each must be categorised as authentication, marketing or utility, and the category affects the price. Meta says review can take up to 24 hours. A booking reminder or an overdue-invoice nudge is usually a template, because it is sent when no window is open. With coexistence, the window applies to API messages only: messages sent from the app do not open or affect it.

Opt-in

Meta requires businesses to obtain opt-in before messaging people on WhatsApp. The person must be clearly told that they are agreeing to receive messages from your business, and your business name must be clear. Meta lists SMS, a website, a phone call flow and in person or on paper as ways to collect it. You choose the method, but it has to comply with the laws that apply to your communications.

For a system, that means storing the opt-in on the customer’s record: when, how and what they agreed to. Without it, a reminder cannot be sent. It is the sort of detail a CRM is good at, and a shared phone is not. In a custom CRM the opt-in sits on the client record.

What Meta charges

I give no figures here, because Meta sets them and changes them. What the documentation says is that, since 1 July 2025, Meta charges per delivered message instead of per conversation. The rate depends on the message category and on the recipient’s country calling code. The business pays Meta, and messages that users send to the business are free.

Which messages are free has also changed more than once, including changes dated 1 October 2026 for service messages beyond a monthly allowance. Meta may update prices on 1 January, 1 April, 1 July or 1 October. So the right move is to read the current pricing page when you plan, and to treat any figure in a blog post, including mine, as out of date. Messages sent from the free Business app stay free.

Limits and verification

Meta caps how many unique customers a business can message outside the service window in a moving 24-hour period. The cap applies to a business portfolio, not a single number, and it can rise when the business is verified or sends high-quality templates to enough people. A new business should expect to start small.

What this means for your business

If you answer a few customers a day from one phone, stay on the free app. Moving to the Platform adds a build, ongoing message charges and opt-in rules, and you would not get much back.

The Platform earns its place when WhatsApp is a main channel and you need it inside your system: enquiries filed against the right client, several staff replying, reminders sent on a schedule, or a bot that handles the first answer. Storex works this way, with WhatsApp in one inbox alongside Gmail, Messenger and Instagram. See WhatsApp integration for what I build, or the wider integrations service. In the quote builder a WhatsApp connection is about 17–30 hours, and you can start from the quote builder.