Sierra
AI customer service agents
Sierra is a conversational AI company, co-founded by Bret Taylor and Clay Bavor, that builds customer service agents for large businesses across chat, messaging, email and phone. Its voice agents handle inbound and outbound calls, can collect card and ACH payments over the phone (card details by keypad tones), and hand calls to human representatives with an AI-written summary. Agents are built and tested with Sierra's own tooling and sold through its sales team.
- Charges by
- Quote only
- Starts at
- Quote
- How it works
- AI with human backup
- Checked
- October 15, 2026
Pricing
No prices are published. Sierra's December 10, 2024 blog post says it uses outcome-based pricing: it charges for agreed outcomes such as a resolved support conversation, a saved cancellation or an upsell, and in most cases does not charge for unresolved or escalated conversations. For some interactions, such as routing or greeter conversations, it may bill per conversation instead. It says it does not use seat-based pricing. No unit prices are given, so the model is recorded as custom.
What it does
- Answers inbound calls
- Yes
- Places outbound calls
- Yes
- Books appointments
- Unconfirmed
- Warm transfer to a person
- Yes
- Text follow-up
- Unconfirmed
- Call recording
- Yes
- Transcripts
- Yes
- CRM sync
- Unconfirmed
- Keep your number (porting)
- Unconfirmed
- Spanish
- Unconfirmed
- Other languages
- Yes
- Web chat
- Yes
- API
- Unconfirmed
- Custom voice
- Yes
Sierra's voice page says it speaks 55+ languages and can switch languages mid-conversation. Its channels page says it works in 58 languages and that its voice models are tuned across 60+ locales. Spanish is not named on the pages reviewed.
Integrations
- Amazon Connect
- Five9
- Genesys
- Twilio
- athenahealth
- Oracle
- Oracle Hospitality
- Plaid
- Apple Business Chat
As listed by Sierra. Integrations not listed may still be possible through an API or Zapier.
Security and compliance
- Signs a HIPAA BAA
- Unconfirmed
- SOC 2
- Unconfirmed
- Discloses it's an AI
- Unconfirmed
Sierra's Trust & Reliability page lists HIPAA among the standards it follows (with SOC 2, GDPR and PCI). None of the pages reviewed say whether Sierra signs a BAA.
“Unconfirmed” means Sierra's public pages don't say either way. Rules for AI phone calls
Company
- Built for
- Enterprise
- Industries
- Financial services, Medical, Telecom, Retail, Government
Sources
- Sierra voice features. Accessed October 15, 2026
- Sierra blog: Sierra speaks (voice launch, Oct 9, 2024) features, integrations. Accessed October 15, 2026
- Sierra product: Channels features. Accessed October 15, 2026
- Sierra product: Trust and reliability compliance. Accessed October 15, 2026
- Sierra partners integrations, affiliate. Accessed October 15, 2026
- About Sierra company. Accessed October 15, 2026
- Sierra blog: Introducing Sierra (Feb 13, 2024) company. Accessed October 15, 2026
- Sierra blog: Outcome-based pricing for AI agents pricing. Accessed October 15, 2026
Spot something out of date? Email contact@aivoiceagentvendors.com with a link to the vendor's page.
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