Call Sandwich

About Call Sandwich

Call Sandwich sells the join between an AI voice agent and the phone system a company already has. Its integration list is the estate rather than the demo: ViciDial, Asterisk, FreeSWITCH, 3CX, NICE inContact, Avaya, Talkdesk, Genesys, Five9, LiveVox, RingCentral and Amazon Connect, alongside carriers including Twilio, Telnyx and Vonage. It ships a self-service SIP switch of its own, sipsandwich.ai, that connects an existing PBX to a voice agent, and states it is an official Jambonz partner.

Retell AI's partner directory lists it at Elite tier, the top rank, with a partnership dating from June 2024, the longest tenure of any Retell partner in this ranking. The agency states 10 million or more AI calls powered, 200 or more enterprise clients, 100 or more integrations built and 22 years of combined telephony experience. Every one of those figures is self-reported, and no client is named anywhere on the site.

Our verdict

For a buyer whose problem is a working contact center that now needs an AI agent inside it, Call Sandwich is the clearest fit on this page: it is the only firm here shipping a product whose job is to bridge an existing PBX to an agent. Nearly everyone else assumes a greenfield line; this one assumes a dialer, a PBX and a queue that already exist, and it has built and sells the SIP plumbing to bridge them. The evidence problem is severe. Not one client is named, the testimonials are anonymized to job titles, the logos on its partner profile do not resolve, and the advisory board page renders unsubstituted template placeholders, so 200 enterprise clients and 10 million calls stand on the company's word alone. Its agent layer also sits on a single vendor, and its own SIP product exists to route traffic into that vendor, so single-supplier risk should be priced into any contract.

Where Call Sandwich ranks

• Ranked #4 in AI Voice Agencies