10 best enterprise AI voice agent vendors in 2026, compared
Samuel Oram-Jones, 13 min read
The best enterprise AI voice agent vendors in 2026 are Bland, Sierra, Decagon, PolyAI, Five9, Replicant, ElevenLabs, Synthflow, Retell, and Vapi, and Bland ranks first because one company builds every AI model on a call. This ranking compares who builds the AI, how each vendor charges, and where calls can run, as of November 2026.
What are the best enterprise AI voice agent vendors?
The best enterprise AI voice agent vendor is Bland, because it builds and runs its own language, speech, and transcription models, and none of the other nine vendors on this list can say that for a whole call.
- Bland: Best overall for enterprise calls
- Sierra: Best for enterprise teams buying outcome-priced agents
- Decagon: Best for support teams adding voice to chat and email
- PolyAI: Best for enterprises that want a managed, quoted agent
- Five9: Best for contact centers that staff live agents on seats
- Replicant: Best for contact centers wanting quoted AI agents
- ElevenLabs: Best for teams that already build on ElevenLabs voices
- Synthflow: Best for sales-led, multi-channel voice teams
- Retell: Best for developer teams that pick their own model and voice
- Vapi: Best for developers assembling their own voice stack
What should buyers check in enterprise AI voice agent vendors?
Buyers should check who builds each model on a call first, because security review, cost, and how a call sounds all depend on how many companies sit behind it.
Vapi and Retell take their language and transcription models from other companies, and Sierra, Decagon, PolyAI, ElevenLabs, and Synthflow each mix models of their own with outside ones.
Sierra says it combines "frontier, open-weight, and proprietary models", and Decagon says it uses "models from the frontier labs, along with our models developed by Decagon Labs". Bland builds its language, speech, and transcription models itself, so a security review clears one AI company where most of the others add outside names.
Where a call may run comes next, because security rules decide where audio may be processed. Enterprise customers get dedicated orchestration and dedicated GPUs run by Bland.
Compliance paperwork matters as much as the feature list. A BAA is the contract HIPAA requires before a vendor handles patient information, and card payments need a clear PCI DSS statement. Sierra, Decagon, PolyAI, Replicant, ElevenLabs, Synthflow, Retell, and Vapi all cover SOC 2, and Bland self-attests to PCI DSS v4.0.1 and shares its attestation under NDA on Enterprise.
Bland and ElevenLabs hold FedRAMP 20x Class A, while Sierra's FedRAMP High is held through Knox Systems rather than its own authorization.
Proof at volume is a check too, such as a customer replacing an IVR (an automated phone menu) with a voice AI agent. Idaho Housing and Finance Association saves $750,000 a year by replacing its IVR with Bland, which handles 4,000 inbound calls a day and cut average call time by 20%.
"We save thousands of dollars a day."
Greg Blake, Chief Information Officer, Idaho Housing and Finance Association
Messaging beside voice is the last check. Bland runs branded iMessage agents natively on Enterprise, on the same pathways as its voice agents. Sierra supports Apple Business Chat, and Decagon, PolyAI, Five9, Replicant, ElevenLabs, Synthflow, Retell, and Vapi don't offer iMessage agents as of November 2026.
How do the 10 best enterprise AI voice agent vendors compare?
These ten vendors differ most in how much of a call each builds itself and in how each is bought, and Bland is the one that builds all of it and publishes a rate.
1. Bland: Best overall for enterprise calls
What does it do? Bland is a full stack provider that builds and runs its own language, speech, and transcription models for inbound and outbound calls, with a visual builder called Pathways where teams connect steps and test them before launch. It publishes sub-200ms latency and a 99.9% uptime SLA, and it serves more than 250 enterprise customers.
Who is it for? Bland suits enterprises and contact centers in any industry that run high-stakes calls at volume. Enterprise customers get dedicated orchestration and dedicated GPUs run by Bland.
Pros
- No outside AI lab in the call path, so a security team reviews one AI company
- Dedicated orchestration and dedicated GPUs run by Bland, on Enterprise
- Bland Speech v3 ranked first of 13 AI voices on Audio Realism Bench on 4 August 2026
- Call grading on the audio as well as the transcript
- Staged releases that pause a new agent version when it performs worse than the last
- Native iMessage agents on Enterprise, sharing pathways with voice
Cons
- Overkill for a small prototype, because Bland is built for production calls at volume
Pricing: Self-serve Start is $0.14 per minute with no platform fee, and self-serve Build is $0.12 per minute with a $299 monthly platform fee. Phone is billed separately at carrier cost.
Enterprise pricing is custom, set with Bland's sales team. Enterprise adds native iMessage agents, warm transfers, a BAA, SSO, data residency, dedicated GPUs run by Bland, and forward-deployed engineers, alongside SMS and web chat.
2. Sierra: Best for enterprise teams buying outcome-priced agents
What does it do? Sierra sells a managed AI agent platform for customer service across chat, voice, email, SMS, and WhatsApp. Behind each agent sits what Sierra describes as a mix of frontier, open-weight, and proprietary models, and Sierra says it "automatically switches between LLM providers to optimize your agent".
Who is it for? Sierra suits enterprise customer experience teams that want a managed agent and are happy to negotiate pricing.
Pros
- Holds SOC 2, HIPAA, GDPR, PCI, ISO 27001, and FedRAMP High through Knox Systems
- Says it holds PCI DSS Level 1 Service Provider certification
Cons
- No published rate, because charges follow outcomes agreed with each customer
- Mixes frontier models from outside AI companies with some of its own, and has no self-serve mode
Pricing: Sierra says "Sierra gets paid only when we complete a task for you", and publishes no rate. It says routing or greeter-style interactions may fit consumption-based pricing, where payment follows conversation count.
3. Decagon: Best for support teams adding voice to chat and email
What does it do? Decagon sells AI agents for customer support across chat, email, and voice, and says it unifies them in a single intelligence layer. Voice runs on Chord, which Decagon calls its own speech model, alongside outside speech models it says it still uses.
Who is it for? Decagon suits support teams that want one agent across chat, email, and voice.
Pros
- Supports 70+ languages with automatic detection and language switching
- Holds SOC 2 Type II, ISO 27001:2022, and PCI DSS 4.0.1
Cons
- No published rate for either per-conversation or per-resolution pricing
- Decagon says "Gray areas can lead to billing disagreements"
- No iMessage agents
Pricing: Per-conversation pricing is a fixed rate for every incoming conversation, and per-resolution pricing is a higher fixed rate for each fully resolved conversation. Decagon publishes no rate for either, and says larger resolution commitments lower the rate.
4. PolyAI: Best for enterprises that want a managed, quoted agent
What does it do? PolyAI builds and runs a voice agent for a customer on quoted per-minute pricing, with its own Raven model family beside GPT and Claude models. It also sells a Dialog-RSN-1 model API at 2¢ per connected minute, without telephony or orchestration.
Who is it for? PolyAI suits large consumer-facing companies that want it to build and run their agent for them.
Pros
- PolyAI handles the build and the ongoing running
- Holds SOC 2 Type II and ISO/IEC 27001
Cons
- No public rate for a managed agent
- Its contract says "the total handle time is rounded up to the next 30-second increment"
- No iMessage agents
Pricing: A managed agent is quoted per minute with no public rate.
5. Five9: Best for contact centers that staff live agents on seats
What does it do? Five9 sells a cloud contact center platform priced in seat bundles, with voice, chat, email, SMS, and social messaging channels and add-on AI. Five9 offers "AI : 3000 minutes per bundled seat + usage", so voice automation sits inside a platform built around human agents.
Who is it for? Five9 suits contact centers that staff human agents and want a seat-priced platform with AI add-ons.
Pros
- Voice, chat, email, SMS, and social messaging on one platform
- Has a "99.999%" SLA
Cons
- Seat pricing with a minimum of 50 seats, and no per-minute AI rate published
- No iMessage agents
Pricing: Seats start at $119 a month for Digital and $159 a month for Core, and Five9 says "Prices above are per concurrent user and usage-based pricing may apply, with a minimum of 50 seats."
6. Replicant: Best for contact centers wanting quoted AI agents
What does it do? Replicant sells AI agents for customer service across voice, chat, and SMS on quoted usage-based pricing. It says its agents are powered by "multiple, fine-tuned LLMs".
Who is it for? Replicant suits large contact centers that want a vendor-run deployment with contracted business outcomes.
Pros
- Holds SOC 2 Type 2 and PCI DSS
- Advertises "99.95%+ uptime"
- Voice, chat, and SMS on one platform
Cons
- Pricing sits behind a pricing request form
- No iMessage agents
Pricing: Quote only, through a pricing request form.
7. ElevenLabs: Best for teams that already build on ElevenLabs voices
What does it do? ElevenLabs sells ElevenAgents, a platform for voice and text agents built on its own speech and transcription models, with a choice between its Realtime models and an outside language model. ElevenLabs charges no telephony fee, and a connected provider such as Twilio bills its own carrier charges.
Who is it for? ElevenLabs suits developer and enterprise teams that want ElevenLabs voices inside an agent platform and will pick a language model themselves.
Pros
- Runs its own speech and transcription models
- Plans from $6 a month with a call allowance
Cons
- Language model usage billed on top in Custom mode
- Call grading reads transcripts only, not the audio
- ElevenLabs says "HIPAA support is available when Zero Retention Mode is enabled and a Business Associate Agreement (BAA) is in place"
- Eleven v3 ranked 12th of 13 AI voices on Audio Realism Bench on 4 August 2026
- No iMessage agents
Pricing: $0.08 per minute past a plan's allowance, with plans from $6 a month and language model usage billed on top in Custom mode.
Teams weighing ElevenLabs against other options can read ElevenLabs alternative for enterprises and Best ElevenLabs alternatives.
8. Synthflow: Best for sales-led, multi-channel voice teams
What does it do? Synthflow sells voice agents through one annual enterprise agreement that scopes in telephony, integrations, and launch support, and it offers WhatsApp and SMS chat beside voice. Synthflow says it is built on "proprietary orchestration and models from OpenAI, ElevenLabs, Deepgram, and custom in-house logic".
Who is it for? Synthflow suits mid-market and enterprise teams that want a sales-scoped platform and are happy to sign an annual agreement before they launch.
Pros
- Holds SOC 2 Type 2 and ISO/IEC 27001, with HIPAA and GDPR coverage
- Forward-deployed engineers launch agents with a customer's team where the agreement includes launch support
- WhatsApp and SMS chat channels
Cons
- Annual enterprise agreement only, with no free plan or trial and no rate by the minute
- No iMessage agents
Pricing: Annual agreement only, with no public per-minute rate, and purchased phone numbers cost $1.50 a month.
9. Retell: Best for developer teams that pick their own model and voice
What does it do? Retell is a platform for building and monitoring AI voice and chat agents, billed per minute with the language model and voice priced as separate lines. A customer's own SIP trunk (a connection to the phone network) carries no Retell phone charge, and phone on Twilio or Telnyx is billed on top.
Who is it for? Retell suits developer-led teams that want to choose their own language model and voice and pay per minute.
Pros
- A wide choice of language models and voices
- Covers SOC 2, HIPAA, and GDPR
Cons
- Advertises "We guarantee >99.9% uptime", while its terms say "at least 99.5% uptime"
- PII (personal data) Removal adds $0.01 a minute
- No iMessage agents
Pricing: $0.07 to $0.31 per minute depending on the language model and voice, with Retell Voice Infra, GPT-4.1, and an ElevenLabs Flash voice coming to $0.14 per minute before phone.
10. Vapi: Best for developers assembling their own voice stack
What does it do? Vapi is a developer platform that hosts voice agents and bills the language model, transcription, and voice from other companies on top at cost. Vapi says it passes these through with "no markup", so a team picks and wires every provider itself.
Who is it for? Vapi suits developers who want to pick and swap each AI provider themselves and can run a stack of several vendors.
Pros
- A team can choose every model and voice
- Imported numbers are billed by a customer's own phone provider
- Vapi says it is SOC 2 Type II attested
Cons
- Language model, transcription, and voice bill from other companies on top of $0.05 hosting
- HIPAA is a $2,000 monthly add-on
- No iMessage agents
Pricing: $0.05 per minute for hosting, plus a language model, transcription, and voice at provider cost, which Vapi's pricing calculator puts at up to $0.0452, $0.0099, and $0.0238 a minute, before phone.
How were these vendors ranked?
Vendors were compared on who builds the AI, where calls can run, how each is priced, compliance, and voice realism, with weight on what enterprise calls need. Every claim about a vendor comes from its own public pages as read in November 2026, and voice scores come from Design Arena's chart of 4 August 2026.
Closer comparisons sit in Bland vs Sierra, Bland vs Decagon, Bland vs PolyAI, Bland vs ElevenLabs, Bland vs Synthflow, Bland vs Retell, and Bland vs Vapi. Related reading includes Enterprise AI voice solutions, Best Cognigy alternatives, and AI voice agents for enterprise call management.
How much do enterprise AI voice agent vendors cost?
Six of these ten vendors publish no per-minute rate for their AI, so a buyer has to ask each for a quote, while Bland's self-serve Start plan is $0.14 per minute for its language model, transcription, and speech together. Bland replaced an earlier flat $0.09 rate with self-serve Start and Build in December 2025.
Enterprise pricing is custom, set with Bland's sales team.
Sierra bills by outcome and Decagon bills by conversation or resolution. PolyAI and Replicant bill by quote, Synthflow by annual agreement, and Five9 by seat, so no per-minute bill can be added up for them.
Retell's card adds its sample voice, model, and infrastructure lines, Vapi's card adds hosting to the top of each range on its pricing calculator, ElevenLabs' card adds the calculator's default model to a call minute, and phone is billed by whichever provider a customer connects.
Every total below is AI before phone, with Retell, Vapi, and ElevenLabs at their published or calculator defaults.
| Vendor | What a minute pays for | Total per minute | Phone |
|---|---|---|---|
| Bland Start (self-serve) | All AI: model, transcription, speech $0.14 | $0.14 before phone | Billed separately at carrier cost |
| Retell | Voice infrastructure $0.055, GPT-4.1 $0.045, ElevenLabs Flash voice $0.04 | $0.14 before phone | Twilio at $0.015 a minute, billed on top |
| Vapi | Hosting $0.05, Transcription $0.0099, Language model $0.0452, Voice $0.0238 | $0.1289 before phone | Free on Vapi numbers, billed on top on Twilio at up to $0.014 a minute |
| ElevenLabs Agents | Call minute $0.08, Gemini 2.5 Flash, the calculator's default model $0.0029 | $0.0829 before phone | No ElevenLabs telephony fee, with a connected provider billing on top |
Bland Start (self-serve): Self-serve Start has no platform fee. Self-serve Build is $0.12 a minute plus $299 a month. Phone and transfers bill separately. Retell: Retell Voice Infra, GPT-4.1, and an ElevenLabs Flash voice, before Twilio phone minutes. Vapi: Hosting plus the top of each range on Vapi's pricing calculator, before phone. ElevenLabs Agents: ElevenLabs call minute plus its pricing calculator's default model, before the customer's own phone provider.
Which enterprise AI voice agent vendor sounds most like a real person?
Bland Speech v3 ranked 1st of 13 AI voices on Design Arena's Audio Realism Bench on 4 August 2026, at 1365, and every outside voice in those results that the other nine vendors let a customer choose scored lower.
- #1BlandBland Speech v31365
- 4thOpenAI, on RetellGPT Realtime 21119
- 4thOpenAI, on VapiGPT Realtime 21119
- 12thElevenLabsEleven v3Near the bottom938
- Not rankedRetell's own voicesNot ranked
- Not rankedVapi's own voicesNot ranked
Ranks are among 13 AI voices, and each rival shows the highest listed voice a customer can choose on it, named for the company that made it. Real human recordings scored 1500, at the right edge of this scale. Bars start at 600, not zero. Source: Design Arena's published results.
On Retell the highest outside voice was OpenAI's GPT Realtime 2, 4th at 1119, and on Vapi it was the same model. ElevenLabs' Eleven v3 ranked 12th at 938, and it is the one outside voice in those results that Synthflow offers.
Decagon uses two outside voice companies: Cartesia's Sonic 3.5 scored 1096 and ElevenLabs' Eleven v3 scored 938. PolyAI offers outside voice providers.
Frequently asked questions
What is the best enterprise AI voice agent vendor?
Bland is the best enterprise AI voice agent vendor as of November 2026, because one company builds every model on a call and the rate is published. Enterprise customers get dedicated orchestration and dedicated GPUs run by Bland.
Which enterprise AI voice agent vendors are HIPAA compliant?
Bland is HIPAA compliant and includes its BAA on Enterprise. Vapi sells HIPAA mode as a $2,000 monthly add-on, ElevenLabs applies its BAA only while Zero Retention Mode is on, and Synthflow offers a BAA. Sierra, Decagon, Retell, and Replicant cover HIPAA, and PolyAI says "Where relevant, our systems are designed to meet HIPAA", as of November 2026.
Is Bland only for outbound calls?
No, Bland runs inbound and outbound calls, including AI receptionist and contact center work, and it also runs SMS and web chat.
Is Bland only for developers?
No, Bland isn't only for developers. Pathways gives teams a visual builder, Norm helps build agents, and on Enterprise forward-deployed engineers build alongside a customer's team.
Does Bland use an open-source model?
No, Bland operates a closed-source model that it developed itself, so its language model isn't an open-source model and no outside AI lab sits behind it.
Which enterprise AI voice agent vendors support iMessage?
Bland runs branded iMessage agents natively on its Enterprise plan. Sierra supports Apple Business Chat, and Decagon, PolyAI, Five9, Replicant, ElevenLabs, Synthflow, Retell, and Vapi don't offer iMessage agents as of November 2026.
How much does an enterprise AI voice agent cost per minute?
Retell charges $0.07 to $0.31 per minute, Vapi charges $0.05 per minute for hosting alone, and ElevenLabs charges $0.08 per minute past a plan's allowance, while Sierra, Decagon, PolyAI, Five9, Replicant, and Synthflow publish no per-minute rate for a managed agent. Bland is $0.14 per minute on self-serve Start for all of its AI, before phone.
Can I keep my phone carrier if I move to Bland?
Yes, Bland connects to a carrier or phone system over SIP, so numbers and routing stay in place.
