Best Telephony for Voice Agents (2026)
Voice agents need a carrier for phone numbers, inbound and outbound minutes, and often SIP or WebSocket audio streaming. Prices below are each vendor's published US rates from their official pricing pages. International and volume discounts vary; none of these dollar figures are negotiated enterprise quotes.
Telnyx, Twilio, Vonage and Plivo compared on published US voice and SIP rates for connecting AI phone agents.
| Tool | Starting price | Best for |
|---|---|---|
| $0.002/min + SIP trunking | Low-cost carrier for voice agents | |
| US local: $0.0140/min outbound, $0.0085/min inbound | Phone numbers and call transport under any voice agent stack | |
| US: $0.00495/min inbound, $0.01446/min outbound | Developers who need programmable voice with SIP, WebRTC and WebSocket connections | |
| US local: $0.0115/min out, $0.0055/min in | US telephony for AI agents |
Prices from vendors' official pricing pages, checked October 14, 2026. Not sponsored; order isn't a ranking.