Complete guide: WhatsApp Business API for businesses in 2026

WhatsApp has over 2 billion active users and is the preferred messaging channel in Spain and Latin America. Integrating the WhatsApp Business API into your business is no longer optional.

WhatsApp Business App vs API: Which do you need?

Feature	Free App	API
Simultaneous users	1-4	Unlimited
Automation	Basic	Full
CRM integration	No	Yes
AI chatbot	No	Yes
Bulk messages	No	Yes (with templates)
Cost	Free	Per conversation

If you have 50+ conversations/day or need automation, you need the API.

Requirements for WhatsApp Business API

1. Meta Business account: Verified with company documents
2. Dedicated phone number: Cannot be registered on personal WhatsApp
3. BSP provider: Business Solution Provider authorized by Meta (AgenteUno manages this for you)
4. Messaging policy: Comply with Meta's content and consent policies

API costs in 2026

Meta charges per conversation (24-hour window), not per message:

• User-initiated conversations: $0.03-0.08 (varies by country)
• Marketing conversations: $0.05-0.15
• Utility conversations (reminders, updates): $0.02-0.05
• 1,000 free service conversations each month

With AgenteUno, API costs are included in your plan. You don't pay Meta directly.

Step-by-step setup

1. Business verification

Meta requires verifying your business identity. You'll need:

• Company tax ID
• Official document (certificate of incorporation, utility bill)
• Verified web domain

2. Number registration

The number you use for the API must be exclusive. We recommend a new number specifically for WhatsApp Business.

3. Connection with AgenteUno

With AgenteUno, connection is automatic:

1. Go to Settings → Channels → WhatsApp
2. Click "Connect WhatsApp"
3. Follow the Meta Business flow (2 minutes)
4. Your AI agent starts responding automatically

4. Message templates

To initiate conversations (not reply), you need Meta-approved templates:

• Appointment reminders
• Order confirmations
• Post-sale follow-up
• Offers (with prior consent)

Best practices

• Respond quickly: The first 24h from customer message are free
• Personalize: Use customer name and context data
• Don't spam: Meta penalizes accounts with spam reports
• Provide value: Every message should be useful to the customer
• GDPR compliance: Get explicit consent before sending marketing

Why use AgenteUno for WhatsApp

1. No technical management: We handle the API, you configure the responses
2. Native AI: Your agent understands natural Spanish, it's not a button bot
3. Multichannel: Same agent handles WhatsApp, web chat, SMS, voice, email, Instagram and Facebook
4. Analytics: See conversations, response time and satisfaction

Activate WhatsApp on your agent →