Ranking updated 1 September 2026Listings reviewed 30 August 20265 agencies reviewedHow we rank
SaaS teams automate onboarding, product-usage signals, billing operations and support routing, and expect an agency to work comfortably with APIs and a data warehouse. The agencies below have delivered against that standard.
Every agency below appears in our full ai voice agencies ranking and states SaaS companies among the sectors it works with. Listings are ordered by their position in that ranking.
Teams that treat a phone line as production infrastructure and want latency, evaluation and monitoring specified before launch rather than discovered afterwards.
Contact centers and enterprises with an existing PBX or dialer that need an agent placed inside the estate they already run rather than a replacement for it.
Intake-heavy businesses that want a receptionist or qualification agent running quickly on a rolling agreement, and are buying an outcome rather than an architecture.
Not published
Not published
Undisclosed
The full reviews
The table is the summary. Below, every agency gets the complete assessment: what it is genuinely good at, where it falls short, and the facts behind its position.
Best forTeams that treat a phone line as production infrastructure and want latency, evaluation and monitoring specified before launch rather than discovered afterwards.
Softcery is the reference point for what a serious voice engagement should disclose before anything is signed. Latency is published as a budget with each stage attributed, the telephony and speech vendors are named rather than hidden behind a platform, and the service is structured as advise, then build, then operate, which matches how phone systems actually fail. The gap is commercial rather than technical. No price appears anywhere on its own site, the three-part structure means the real number only emerges after scoping, and the independent record is 12 Clutch reviews, a thinner base than several less specialized firms on this page carry. A buyer who needs a figure approved before a scoping call will not find one here.
Pros
Publishes a component-level latency budget from its own production traffic, including a p95 figure and a stall rate
Names the full stack, from LiveKit, WebRTC and SIP to Deepgram, Cartesia and Grafana monitoring
Names five clients and runs two live demos a buyer can call rather than watch
Publishes reference on-premises hardware at $4,000 to $12,000 for buyers who cannot send audio off site
Cons
Publishes no price of its own, so the only planning figure is the $10,000 minimum Clutch displays
The advise, build and operate structure means total cost only becomes clear after scoping
Twelve Clutch reviews is a thin independent record next to the larger review bases elsewhere in this ranking
HQ
Tallinn, Estonia
Team
11-50
Pricing
$10,000+ minimum, $50-$99/hr (Clutch-displayed); own site sells advisory on an availability retainer, build work per statement of work, and operations on a retainer, with no figures published
Best forBuyers who want a latency figure and a cost per connected minute in writing early, and who do not need to know which infrastructure the work runs on.
DestiLabs gives a buyer two of the three numbers that decide a voice project, latency and cost per connected minute, and pairs them with the larger of the two 5.0 Clutch scores on this page. What it withholds is the third. Nowhere does it name a telephony provider, a speech vendor or an orchestration framework, so there is no way to judge whether 1.2 seconds was achieved on infrastructure that would survive your call volume, and no way to assess how much of the build would transfer if the relationship ended. Its self-reported scale also disagrees between sources, at 50 projects and $20M of client revenue on its own homepage against 200 projects and $100M on its DesignRush profile. Treat the published latency as the opening of a technical conversation rather than a specification.
Pros
Publishes end-to-end latency and cost per connected minute on two voice case studies
Clutch shows 5.0 from 23 reviews, the larger of the two perfect scores in this ranking
Clutch publishes a $10,000 entry point and a $50 to $99 hourly band
Cons
Names no telephony, speech or orchestration vendor anywhere, so the published latency cannot be tied to a stack
Self-reported scale disagrees between sources: 50 projects and $20M of client revenue on its own site against 200 projects and $100M on DesignRush
Voice sits inside a menu that also covers computer vision and generative imagery
Publishes its own best-voice-agency listicles, which is a self-promotion signal on a page a buyer might otherwise read as research
HQ
Tallinn, Estonia
Team
11-50
Pricing
$10,000+ minimum, $50-$99/hr (Clutch-displayed); DesignRush instead shows a $10,000-$25,000 minimum and $70/hr
Best forContact centers and enterprises with an existing PBX or dialer that need an agent placed inside the estate they already run rather than a replacement for it.
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.
Pros
Integrates with legacy contact center estates by name, including ViciDial, Avaya, Genesys and NICE inContact
Ships its own SIP switch connecting an existing PBX to a voice agent, and states official Jambonz partner status
Holds the top tier and the longest partner tenure of any Retell AI partner in this ranking
Cons
Names no client anywhere and anonymizes its testimonials, so 200 enterprise clients and 10 million calls rest on its own word
The agent layer sits on a single vendor, and its own SIP product routes traffic into that same vendor
Publishes no price and no team size, and no independent review profile was located
Its advisory board page renders unsubstituted template placeholders, so no advisor is actually named
Best forCompanies that need a price agreed before work starts, and are buying product engineering with a voice component rather than a voice specialist.
RaftLabs is the clearest firm on this page about what a project will cost, and for a buyer who needs a number approved before a scoping call, that counts for something real. The service description also shows awareness of what breaks a phone deployment, including interruption handling, fallback and retry logic. It ranks low for two reasons. Voice is one line on a general product menu, the flagship AI agent service page names no voice vendors at all, the voice client is not named, and much of the voice content on the site is listicle material aimed at search rankings rather than at showing how anything was built. Separately, its own copy claims a 4.9 rating across 50 or more verified reviews, while the Clutch profile it cites displays 18. The score matches; the review count does not, and pricing transparency and public accountability are two of the five criteria this ranking is decided on.
Pros
Publishes fixed price bands on its own site, from $20,000 to $50,000 for a single-workflow agent
Bills fixed price with no hourly billing, so scope changes are negotiated rather than metered
Its voice service description covers interruption and fallback handling, transcription and SMS retry logic
Cons
Its own copy claims a 4.9 rating across 50 or more verified reviews, while the Clutch profile it cites displays 18
Voice is one line on a general product development menu, and the flagship AI agent page names no voice vendors
The voice client is not named, and much of the voice content is listicle material aimed at search rankings
Its about page displays logos including Vodafone, Nike and Microsoft that are implausible as direct clients at this size and price
HQ
Dublin, Ireland
Team
Not published
Pricing
Fixed-price only, no hourly billing: single-workflow agent $20,000-$50,000 over 4-8 weeks, multi-agent systems $60,000-$150,000 over 10-16 weeks, MVP work from about $10,000; Clutch shows a $10,000+ minimum and $25-$49/hr
Best forIntake-heavy businesses that want a receptionist or qualification agent running quickly on a rolling agreement, and are buying an outcome rather than an architecture.
Agento AI is buying-an-outcome territory. The volume recorded on its platform vendor's directory is the largest shown there for any partner on this page, the named client organizations are checkable, and 30-day rolling agreements after a two to three week implementation is a low-commitment way to find out whether a voice agent works on an intake line. For a buyer who needs to understand what they are running, the record is thin to the point of absence. Nothing technical is published, no latency or interruption behaviour is stated, no call testing method is described, and the compliance page that would carry a HIPAA or call-recording position returns a 404, which matters given the fertility and legal intake work it names. Its headquarters also disagrees between sources, with a Wyoming address of the kind registered-agent services use on its own site against New York on the vendor directory, and no founding year, team size or price is published anywhere.
Pros
Retell AI's directory records 250,000 or more calls a month, the largest monthly volume shown there for any partner here
Names four client organizations across legal intake, insurance, fertility concierge and payments
States a two to three week implementation on 30-day rolling agreements, a low-commitment entry
Cons
Publishes nothing technical: no latency, no telephony detail, no interruption handling and no call testing method
Its own how-it-works and compliance pages return 404, so no HIPAA or call-recording position can be checked
Headquarters disagrees between sources, and no founding year, team size or price is published
Delivery rests on one platform vendor, and the rest of the stack it names is generic
HQ
Not published
Team
Not published
Pricing
Custom pricing scoped per engagement, a stated two to three week implementation and 30-day rolling agreements; no figures published
