A software as a service (SaaS) platform sends, to an end user device, a message of a messaging conversation between the end user device and a first client device associated with a first user account of the SaaS platform. The message is associated with a first telephone number provisioned by the SaaS platform. The messaging conversation is associated with a messaging conversation identifier. The end user device is associated with a second telephone number. The first client device is associated with a third telephone number. a first request to place a voice call is received, via a first application programming interface (API) call from the first client device, based on the messaging conversation identifier. Responsive to receiving the first request, the voice call to the second telephone number is placed. The voice call is associated with the first telephone number provisioned by the SaaS platform.