Retell AI

Retell AI sells voice infrastructure to developers, not a finished product for a support team. You bring the phone number, the CRM and the workflow; it supplies turn-taking, transcription and telephony glue. Its connector catalogue is thickest in healthcare, and a HIPAA BAA is self-serve at no extra cost.

There is no plan price. The advertised $0.07 to $0.31 a minute is a composite of meters you assemble: $0.055 for Retell Voice Infra, $0.015 to $0.040 for text-to-speech by voice provider, $0.003 to $0.32 for one of twenty-two cascading models, and $0.015 for telephony. Calls are tracked to the second, never rounded up. Concurrency is the only capacity charge, $8 a month per concurrent call above the first twenty.

By its own statement it does not operate in the European Union, so EU and UK data subjects get a DPA with Standard Contractual Clauses instead of a region. Billing covers the whole call because the speech-to-text engine listens through silence, and the agent fee stops only once a call transfers, so a failed conversation still costs. An SLA with credits, SSO and RBAC are Enterprise only, and no sub-processor list, language count or pass-through statement is published.

PolyAI publishes no rate at all, which makes Retell the rare AI voice agent you can cost before a sales call. Vapi and Bland AI meter minutes the same way. Lorikeet bills 1.5 credits per resolved voice ticket instead, so a call the agent fails costs nothing there and full price here.