The closest like-for-like: an enterprise inbound voice agent sold through a demo request, with no rate anywhere on the site. PolyAI publishes the unit it bills, a minute of voice, and withholds only the number; Parloa withholds the unit as well.
Also sales-gated, but it names a billable event, a resolved conversation, so a buyer can at least model the shape of the bill. Sierra is chat-first with voice added in 2025 and runs on Twilio and Amazon Connect, where Parloa has carried production phone traffic since 2018 on telephony it owns.
The counterexample to the claim that enterprise voice pricing cannot be published: an itemised per-minute rate card covering voice infrastructure, telephony and the LLM line. A developer buyer rather than a procurement one, and no EU data residency commitment to match Parloa's Azure regional hosting.
Digital-first and ticketing-centred, strongest where Zendesk workflows already shape the queue, billing per interaction with a per-resolution option, typically over an annual platform fee. Parloa's centre of gravity is the phone line and the CCaaS layer instead.
6 of 9 not published by Parloa, checked