WhatsApp Business Calling lets your business use WhatsApp as a full voice channel on top of your existing telephony setup. Your customers can call you directly from WhatsApp, and your agents receive those calls exactly like any other inbound call. You can also place outbound calls that ring in the customer's WhatsApp app instead of their regular phone line.
Getting started
Before getting started with WhatsApp Business Calling, please ensure the following are in place:
1. WhatsApp Business Account & Number
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You must have a WhatsApp Business Account (WABA) with business verification completed.
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If you are not yet using WhatsApp messaging with CM.com, onboarding is required first (a channel onboarding fee applies).
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The same number must be configured in the CM.com Voice Management App as an inbound number just like a regular DDI number.
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We will enable the calling feature and need your input on the following settings:
|
Setting |
Required/optional |
Notes |
|---|---|---|
|
Phone number |
Required |
The number to be enabled for WhatsApp Business Calling |
|
Callback permission request |
Optional |
Whether to prompt users for call permission |
|
Call icon visibility |
Optional |
Whether the call button is shown in your profile |
|
Call icon visibility - countries |
Optional |
Restrict call button display by country |
|
Opening hours |
Optional |
If set, timezone and weekly hours are required; holiday schedule is optional |
Using a mobile number? While CM.com 's Voice platform does not generally support mobile number ranges, an exception is made for WhatsApp Business Calling. Please contact support if your use case requires a mobile number.
Note that CM.com will not provide or host mobile numbers. Neither will CM.com terminate inbound PSTN calls for mobile numbers used in this way.
2. PBX / Infrastructure
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Your PBX or telephony infrastructure must support the OPUS audio codec. WhatsApp calls use OPUS as an addition to G711a/u.
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SRTP (encrypted media) is supported but optional. CM.com handles SRTP re-encryption on your behalf.
3. Agent Tools
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For outbound calls from a PBX: agents must be able to dial a prefix (*WA or *92) before the destination number. This is typically a simple configuration in your PBX.
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For app-based call handling (FlowBuilder, Native Voice in Mobile Service Cloud, or HALO), the relevant product must be included in your CM.com order.
Inbound call flow (WhatsApp user → Business)
When a WhatsApp user taps the call button in your WhatsApp Business profile or chat, here is what happens:
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The call is delivered to CM.com's Voice platform.
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The call is routed to your PBX, call queue, IVR, or one of CM.com's applications (FlowBuilder, Native Voice in Mobile Service, or HALO).
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Your agent answers the call on their phone or softphone, just like any other inbound call.
Outbound call flow (Business → WhatsApp user)
Once a WhatsApp user has given your business permission to call them via WhatsApp, your agents can place calls that ring directly in the WhatsApp user’s app, instead of over the regular phone network.
Agents can initiate outbound WhatsApp calls in two ways:
Option A: Via your PBX (using a dialing prefix)
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The agent dials a special prefix before the destination number:
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*WA + destination number, or
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*92 + destination number
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CM.com's Voice platform recognises the prefix and routes the call via WhatsApp rather than the regular phone network.
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The WhatsApp user receives an incoming audio call in their WhatsApp app.
Option B: Via Mobile Service Cloud (Native Voice)
When placing a call from Mobile Service Cloud, agents can select 'WhatsApp' as the call channel. The call is then routed via WhatsApp rather than PSTN.
Note: Full MSC channel selection is coming soon. In the meantime, use the *92 prefix for outbound WhatsApp calls from MSC.
User Call Permissions
Meta requires the user to explicitly permit calls: via an Interactive Call Permission Request message, implicitly when the business receives an inbound WhatsApp call, or by the user opting in via the business's WhatsApp profile.
Meta requires that a WhatsApp user has explicitly granted permission before your business can call them via WhatsApp. There are three ways a customer can grant this permission:
|
Method |
How it works |
|---|---|
|
Permission request message |
Send the WhatsApp user an Call Permission Request message. They tap to approve. |
|
Inbound call |
When a WhatsApp user calls your business via WhatsApp, they implicitly grant outbound call permission for that number. |
|
WhatsApp profile opt-in |
WhatsApp users can grant permission directly via the opt-in option in your WhatsApp Business profile. |
Call permission requests can be sent as:
When a WhatsApp user accept or declines a permission request, a Call permission reply is sent.