The five methods at a glance
Method | Who uses it | Strengths | Typical use case |
Intercom Inbox App | Agents working inside Intercom | One-click from a conversation sidebar; history visible per-contact | Agent answering an Intercom conversation needs to send SMS or WhatsApp without switching tools |
HubSpot extension | Agents and automations in HubSpot | Card on the contact record for ad-hoc sends; workflow action for automation | Sales rep on a HubSpot contact, or a lifecycle-stage workflow triggering a message |
Reach browser extension | Agents working alongside Intercom | Dedicated side panel; contact search and template browser | Intercom agent who wants a quicker, richer compose UI than the native sidebar cards |
API | Developers, backend systems | Programmatic, high-volume, integrates with your stack | Order confirmation on checkout, notification from a backend event |
Broadcasts | Marketing and campaign owners | One-to-many sending with recipient lists and scheduling | Campaign to many contacts; announcement; bulk re-engagement |
What each method supports
Viber Business Messages (VBM) is Viber’s business-grade template channel. The abbreviation VBM is used throughout this section.
SMS (free-text) | WhatsApp template | VBM template | One-to-one | One-to-many | |
Intercom Inbox App | Yes | Yes | Yes | Yes | No |
HubSpot extension | Yes | Yes | Yes | Yes | No |
Reach | Yes | Yes | Yes | Yes | No |
API | Yes | Yes | Yes | Yes | No |
Broadcasts | Yes | Yes | Yes | No | Yes |
Free-text on WhatsApp is only available inside the 24-hour customer service window — outside that window all WhatsApp methods require an approved template.
How to pick
Work through these questions in order — the first “yes” is your answer:
Are you sending to many contacts at once? Use broadcasts.
Is this being triggered by a backend event, not a human? Use the API.
Are you already working in Intercom? Use the Intercom Inbox App.
Are you already working in HubSpot? Use the HubSpot extension.
Do you want a dedicated side panel across tabs, with template browsing and contact search? Use Reach.
Most teams end up using more than one method — an agent tool for ad-hoc sends, the API for automated notifications, and broadcasts for campaigns.
Key differences to know about
CRM integration. The Intercom Inbox App and HubSpot extension are scoped to one CRM each. Reach is the Intercom-paired browser extension.
Conversation creation. Every method lets you optionally open a CRM conversation so replies route back into your inbox. See Understanding the Start Conversation Option.
Templates. If you plan to send WhatsApp or VBM, the template must be approved on the channel before any method can send it. Template approval is a one-time setup per template.
Rate limits. WhatsApp API calls are limited to a rolling per-channel budget — programmatic senders should handle the
429response explicitly. UI-based methods apply the same limits but distribute sends more naturally.
What’s next