What is the WhatsApp Business API?
WhatsApp Business API is Meta's official route for businesses to connect WhatsApp to their systems (CRM, chatbots, AI agents, automation). Unlike the free WhatsApp Business app, the API supports multiple simultaneous users, official templates, automated bots and high message volumes, all in line with Meta's policies.
The API works through official providers (BSPs: Twilio, 360dialog, MessageBird, Vonage) that act as intermediaries between your system and Meta. Each conversation has a cost that depends on the country, the message type (utility, marketing, authentication) and your volume. Meta publishes the price per conversation, and it varies by country and message type; in Spain it comes to cents per conversation.
To use the API you need: a dedicated phone number (one that has never been used on WhatsApp), a verified business account in Meta Business Suite, a chosen BSP, and usually template review and approval if you do marketing. Approval takes between 24h and 72h with the right documentation.
An applied example
An online shop connects its Shopify store to WhatsApp Business API via Twilio. When an order comes in, the customer automatically gets a confirmation with tracking. If the customer replies, an AI agent handles questions about returns, sizing and delivery times. For Black Friday promotions, the business sends a pre-approved marketing template to its opt-in list. Everything is traceable and compliant with Meta's rules.
When it is worth it
- You get more than 50 WhatsApp messages a day and the number is growing.
- You need several staff members or a bot to handle the same number without getting in each other's way.
- You want to send proactive messages (appointment reminders, order confirmations, post-service follow-ups) in line with Meta's policies.
- Your CRM or online shop needs to be triggered by WhatsApp events (new lead, order delivered, etc.).
Common mistakes
- Using your personal number for WhatsApp Business API. It won't work: the number ends up "burnt" for personal use.
- Sending marketing messages outside the 24h window without an approved template. Meta closes accounts for this.
- Paying a BSP that adds a steep markup on top of Meta's official cost. Always compare 2-3 BSPs.
- Not keeping your opt-in list clean. Messaging users who haven't opted in triggers reports and lowers your quality rating.
- Forgetting about GDPR compliance: opt-in must be documented, and users must be able to unsubscribe.
How we do it at STAKKER
STAKKER SYSTEMS sets up WhatsApp Business API on Twilio (quick and well supported) or 360dialog (cheaper at high volume). We include business verification in Meta Business Suite, registration of official templates, integration with n8n and your CRM, and an AI agent if relevant. Scope and price are agreed after a free diagnostic; we don't work with catalogue rates.
Frequently asked questions
How long does Meta take to approve the number?
Between 24h and 72h if your documentation is in order. If your business isn't registered as an SL (limited company) or autónomo (self-employed), it can take weeks or be rejected.
Can I use the free WhatsApp Business app and the API at the same time?
Not with the same number. Each number is on one or the other. The usual approach is to move the business number to the API and keep the app for personal use only.
How much does each conversation cost?
Meta charges based on the message type (utility, marketing, service) and the country; in Spain we're talking cents per conversation, and conversations the customer starts within the 24-hour window aren't charged. The current rate is published by Meta and changes from time to time.
What happens if Meta closes my account?
You lose access to the API with that number. That's why compliance is critical: clear opt-in, no spam, approved templates, and respecting the 24h window for non-template messages.
Related terms
- AI AgentAn AI agent is a software system that combines a large language model (LLM) with access to tools (APIs, databases, messaging) and a goal, so it can carry out tasks with minimal human involvement. The difference from a traditional chatbot is that an agent doesn't just chat: it acts.
- n8nn8n is an open-source automation platform that connects APIs, databases and SaaS tools through visual workflows. It lets you automate business processes without writing glue code, while keeping control of your data.
- AI phone agentAn AI phone agent is a system that answers (or makes) phone calls using a natural synthesised voice, understands the caller in real time, holds a coherent conversation and carries out actions (booking appointments, logging leads, transferring calls). It works 24/7 and handles several calls at once with no queues.