WhatsApp Business Calling API: Requirements, Call Flow and Providers (2026)
- Calling runs over VoIP: signalling by HTTPS webhooks, media by WebRTC with the Opus codec 1.
- Your number must be on the Cloud API, not the WhatsApp Business app, and the business needs a daily messaging limit of at least 2,000 unique recipients 1,3.
- A business has about 30 to 60 seconds after the connect webhook to accept a user-initiated call; after that the caller sees "Not Answered" 2.
- User-initiated calling is available wherever the Cloud API is; business-initiated calling is not available from numbers in the United States, Canada, Egypt, Vietnam or Nigeria 1.
- Meta's calling pages that we read state no price, so any per-minute figure you see elsewhere should be checked against Meta's current rate card 1,2,3.
Meta's WhatsApp Business Calling API lets a business receive and place voice calls with WhatsApp users over the internet. This page walks through what Meta's documentation says you need, how an inbound call is signalled, which settings you control and how the main platforms package it, using the pages as they read on 5 November 2026.
· 9 sources · Published by Convocore, which sells white label AI agents. See method and limits.
What the WhatsApp Business Calling API is
Meta describes it as a way to initiate and receive calls with WhatsApp users using Voice over Internet Protocol, and markets it as free and globally accessible for customers 1. There are two directions. In a user-initiated call a WhatsApp user taps the call button in the chat with your business. In a business-initiated call your business rings the user, which requires the user's explicit permission first 1.
Both a primary phone and a companion iPhone or Android device can call in, but callback permission is not yet supported on companion devices 2.
What you need before calls can reach you
Meta's setup page lists the prerequisites. The business number must be in use with the Cloud API and not the WhatsApp Business app, the app must be subscribed to the calls webhook field (unless you use SIP) and to the phone number's messaging account, it needs the whatsapp_business_messaging permission, and calling must be enabled on the number 1. The business also needs a daily messaging limit of at least 2,000 unique recipients 1,3.
Calling is off by default and is switched on through the settings endpoint or in WhatsApp Manager under Account tools, Phone numbers, then the Calls tab 3. Meta says changes can take up to 7 days to reach every user's app, though most refresh sooner 3.
How an inbound call is signalled
In the default setup, signalling travels over HTTPS and media over WebRTC (ICE, DTLS and SRTP) using Opus. Meta sends a connect webhook carrying an SDP offer, and your side answers with an accept request that carries the SDP answer 1,2. Meta recommends a pre-accept step because it speeds up connection and avoids audio clipping, and warns that media flowing too early makes the caller miss the first words while media flowing too late leaves them in silence 2.
You must also send a terminate request at the end of every call, even if an RTCP BYE arrives, which Meta says keeps pricing more accurate 2. The terminate webhook reports a status of Failed or Completed along with start time, end time and duration in seconds 2. Meta also documents SIP-based modes that need explicit enablement 1.
- 0 sCaller taps callMeta posts a connect webhook with an SDP offer to your endpoint.
- FastPre-acceptRecommended; speeds up connection and avoids clipped audio.
- Within about 30 to 60 sAcceptSend the SDP answer. Past the window the caller sees Not Answered.
- LiveAudio over WebRTCOpus audio; your voice agent talks and listens here.
- EndTerminateSend terminate yourself; a webhook reports status and duration.
Settings you control
Meta's settings endpoint lets you shape when and how people can call you 3. Voicemail and call hours are mutually exclusive in Meta's docs: when voicemail is enabled, turn call hours off 3.
| Setting | What Meta says |
|---|---|
| Call hours | Time zone required; up to 2 entries per weekday; up to 20 holiday overrides; user-initiated calls are unavailable outside them |
| Callback permission | When enabled, the WhatsApp client offers to chat or request a callback and shows the next available calling slot |
| Country restriction for the call icon | A list of user country codes; an empty list means no restriction |
| Audio codecs | Opus is always enabled; PCMA and PCMU can be added, need transcoding and use about 64 kbps each way |
| Voicemail | Off by default; triggers are reject and timeout; timeout 0 to 30 seconds; announcement under 60 seconds in OGG with Opus |
| Settings webhook | Subscribe to account_settings_update to hear about changes to calling settings |
Business-initiated calls and permission
Calling a WhatsApp user needs the user's explicit permission, which can be requested when they call you 1,3. Meta states production limits per business and user pair of 1 permission request per day and 2 per week, with 25 and 100 for sandbox accounts, and a system message after 2 consecutive unanswered calls with automatic revocation after 4 1.
Business-initiated calling is available wherever the Cloud API is, except from numbers in the United States, Canada, Egypt, Vietnam and Nigeria 1. Twilio's page adds Turkiye to its own list of unsupported sender countries 4. A December 2025 changelog entry on Meta's page mentions a per-user figure of 100 calls per day; Meta's page does not explain how that relates to the permission limits above, so check the current limits before you build outbound flows.
How platforms package it
We read each vendor's own page on 5 November 2026. A blank means the page did not say.
| Vendor | What the page offers | AI voice agent on the call | Price shown for calling |
|---|---|---|---|
| Meta (direct) | The Calling API itself | You build it | None on the pages we read |
| Twilio | Runs on Programmable Voice; inbound goes to your Voice app; up to 1,000 concurrent calls | Not stated; you build the app | None found for calling |
| Wati | User and business initiated calls; AI transcription and summaries | Not stated | Incoming free; outgoing billed per minute by Meta in 6 second steps, no rate shown |
| Gupshup | Voice AI agents over PSTN, SIP and WhatsApp, inbound and outbound | Yes, marketed | None shown |
| Respond.io | WhatsApp Business Calls in the same thread as chat | Not found | None found |
| Infobip | Business calls inside WhatsApp | Not found | Points to its pricing page |
Where Convocore fits
Convocore answers inbound WhatsApp calls with the same AI agent, knowledge base and tools it uses for chat, and logs each call with a transcript in the Calls dashboard. It does not place outbound WhatsApp calls. Calling is switched on per number in the dashboard, and the number must be connected through the Meta Cloud API, so numbers using the WhatsApp Business app side by side with the API do not support calling. Meta's own requirements above (the 2,000 daily limit, the calls webhook subscription) still apply. Check the pricing page for which plan covers voice before you buy 9.
What the evidence does not show
- Meta's support page, with its country restrictions and error codes, did not load for us, so we cite only the availability statements on the calling page.
- We read only the first 39,000 or so characters of two long Meta pages; features described later on them are left out.
- Meta's calling pages show no prices, and we found no concurrent call or call duration limit from Meta itself.
- Meta's call-settings page says disabling the call icon both does and does not stop unsolicited calls, so we do not state which is true.
- We did not test any vendor's WhatsApp calling. Vonage and Vapi pages could not be read.
Choosing a route to WhatsApp calling
If you have engineers, Meta's API plus Twilio gives you full control and you build the voice logic yourself. If your team already lives in a WhatsApp inbox, a platform such as Wati or Respond.io puts calls beside chats. If you want an AI agent to answer the calls, check that the vendor says so on its own pages and ask what it bills per minute.
Method and limits
- Every figure comes from a page opened on 5 November 2026. Where a page contradicts itself we say so instead of picking a side.
- Convocore sells an AI agent platform and has a commercial interest. If you find an error, write to support@convocore.app.
Sources
- WhatsApp Business Calling APIPrimary sourceMeta for Developers. Read 5 November 2026; latest changelog entry 23 March 2026.
- User-initiated callsPrimary sourceMeta for Developers. Read 5 November 2026.We read the first 39,352 of 47,832 characters; the rest is not used.
- Call settingsPrimary sourceMeta for Developers. Read 5 November 2026.We read the first 39,359 of 49,203 characters; the rest is not used.
- WhatsApp Business CallingPrimary sourceTwilio. Page modified 6 October 2026; read 5 November 2026.
- WhatsApp Business Calling APIPrimary sourceWati. Read 5 November 2026.The page contradicts itself on outbound availability in the US.
- Voice AI agentsPrimary sourceGupshup. Read 5 November 2026.Marketing page; no price or Meta requirements shown.
- Respond.io home pagePrimary sourceRespond.io. Read 5 November 2026.
- WhatsApp BusinessPrimary sourceInfobip. Read 5 November 2026.
- Convocore pricingPrimary sourceConvocore. Read 5 November 2026.
Questions
What is the WhatsApp Business Calling API?
Meta's API for receiving and placing voice calls with WhatsApp users over VoIP. Signalling uses HTTPS webhooks and media uses WebRTC with the Opus codec.
What do I need to enable WhatsApp calling?
A number on the Cloud API rather than the WhatsApp Business app, a daily messaging limit of at least 2,000 unique recipients, the calls webhook field subscribed and calling switched on for the number.
How long do I have to answer a WhatsApp call?
Meta says about 30 to 60 seconds after the connect webhook is sent. After that the caller sees Not Answered.
Does the WhatsApp Calling API work in the United States?
User-initiated calling works wherever the Cloud API is available. Business-initiated calling is not available from numbers in the United States, Canada, Egypt, Vietnam or Nigeria.
How much does WhatsApp calling cost?
The Meta calling pages we read show no price. Wati says outgoing calls are billed per minute by Meta in 6 second increments without giving a rate, so check Meta's current rate card.
Can an AI agent answer WhatsApp calls?
Yes, if the platform supports it. Gupshup markets voice AI agents on WhatsApp, and Convocore answers inbound WhatsApp calls with its AI agent. Convocore does not place outbound WhatsApp calls.