WhatsApp Business Calling API: Integration, SIP & Limits (2026)

​The WhatsApp Business Calling API enables businesses to make VoIP calls via the Cloud API. It supports WebRTC and SIP protocols. To start, get a registered business number. You need the whatsapp_business_messaging permission. You also need a messaging limit of at least 2000 conversations per 24 hours.

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​Voice is the new text. Customers want to talk. The WhatsApp Business Calling API bridges this gap. It lets you put VoIP directly into your customer flow.

​We analyzed the architecture. You can stick to the default WebRTC. Or, you can configure SIP for complex setups. But there are strict gates. You cannot just switch it on. You need a high messaging limit first.

​Key Concepts Covered in This Guide

• ​Core Topic Entity: WhatsApp Business Calling API
• ​Primary Problem Entity: VoIP Integration
• ​Core Solution Entity: Cloud API Calling
• ​Supporting Sub-Entities: SIP, WebRTC, Sandbox Testing
• ​Desired Outcome: Seamless Voice Communication

Prerequisites for Cloud API Calling

​You must meet specific criteria. Do this before you make a call.

​This is not for new accounts. The requirements are strict.

• ​Messaging Limit: You need a limit of at least 2000 conversations. This is for a rolling 24-hour period.
• ​App Permissions: Your app must have whatsapp_business_messaging enabled.
• ​Webhooks: Subscribe to the "calls" webhook field.

​WhatsApp Business Calling API works with Cloud API Calling configuration. It solves disconnected support channels. It achieves integrated voice and text.

​If you don't meet the 2000-conversation limit, the features won't work. Scale your messaging first.

You must be on the right platform to use this. If you are unsure about your setup, reading The Real Difference Between WhatsApp Cloud API and On-Prem API (2025 Guide) will clarify why the Cloud API is essential for these voice features.

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Configuration: SIP vs. WebRTC

​Choose your protocol. Default or Custom.

​The API offers flexibility.

• ​Default: This uses SIP with WebRTC. Signaling uses HTTPS/TLS. Media uses WebRTC (ICE + DTLS + SRTP).
• ​SIP (Explicit): You can enable SIP with SDES media. This is for advanced setups. It supports specific audio codecs like OPUS. (G.711 is coming soon).

​Note:SIP configurations require explicit enablement. Check your settings.

​Business-Initiated Calls: Limits & Geography

​You can call customers. But there are limits.

​As of December 2025, the limits increased.

• ​The Limit: You can make 100 business-initiated calls per user. This is a daily limit. (It went up from 10).
• ​The Geography: It works everywhere Cloud API works. EXCEPT: USA, Canada, Egypt, Vietnam, and Nigeria.

​If you target these excluded countries, your calls will fail.

​Testing with Sandbox Accounts

​Test the integration. Use a Sandbox account.

​Don't test in production. It is risky.

• ​Sandbox Limits: Send 25 calls per day. (Production allows only 1 per day for low-tier accounts).
• ​Unanswered Calls: In Sandbox, 5 consecutive unanswered calls trigger a warning. In production, it is only 2.

​Using the Sandbox is smart. It lets you verify your SIP trunking. You can check your logic. You won't get your number revoked.

​Conclusion

​The WhatsApp Business Calling API is powerful. It adds a human touch to your bot. But it requires technical rigor. Check your messaging limits. Configure your SIP correctly. And respect the geographic restrictions.

​Master the WhatsApp Cloud API with WUSeller. Focus on your voice setup. Let us handle your marketing automation. We make the API simple. Start for free today.