Best Phone Automation

Ranked #8 of 8 in AI phone answering for business

Synthflow review

An AI voice agent platform from Berlin for contact centers and multi-location brands, sold only as an annual enterprise agreement.

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Verdict

6.2/10

Pick Synthflow if you run a contact center, BPO or multi-location brand that needs AI agents inside Zoom, Five9 or RingCentral with SOC 2 and ISO 27001 coverage; a small business faces an annual contract with no published price.

Best for Enterprise contact centers

Skip it if you want to sign up today, see a price, or pay by the minute; Synthflow sells only annual enterprise agreements, with no free plan or trial.

Visit Synthflow (opens the Synthflow website)

Synthflow at a glance
DeveloperAgentFlow AI GmbH, Berlin (Charlottenburg local court, HRB 255004 B)1
Founded2023, in Berlin, Germany2
How it is soldAnnual enterprise agreement only; no free plan, no trial, no published per-minute rate3
Built forUpper mid-market and enterprise contact centers, BPOs and multi-location brands4
Scale (vendor figures)1M+ calls a day for 100+ enterprise customers4
SecuritySOC 2 Type 2 report, ISO/IEC 27001, PCI DSS v4.0.1, HIPAA BAA, GDPR DPA5
Data regionUS or EU, chosen when the workspace is created and fixed afterwards6
Latest product updateNovember 6, 20267

How Synthflow scores

Score breakdown for Synthflow
Call quality 25%8.0Synthflow says its agents reply within half a second, let callers interrupt and switch language mid-call8, and its own speech engine targets under 200 ms to first audio9. It runs its own telephony4 and publishes a MOS target above 4.210. These are vendor figures; this site has not measured them. Score: published latency and interruption handling give 8.0.
Setup 20%4.0Synthflow calls its product a no-code platform11, and the docs say a first agent takes a few minutes to build in the dashboard through Prompt Builder, Flow Designer or templates12. Every new deployment starts on an annual Enterprise contract, scoped on a call, and goes live in weeks3; Batteries Plus took five weeks from kick-off to pilot13. Score: an annual contract and a launch measured in weeks give 4.0.
Integrations 15%8.5Real-time booking runs through Cal.com or GoHighLevel14, and custom HTTP actions reach other systems during a live call15. CRM integrations cover Salesforce and HubSpot4, with built-in connections for Zoom, Five9, RingCentral, 8x8, Twilio, Telnyx, Vonage and Freshcaller8; the Zoom app routes calls to US-region workspaces4. Transfers go to a number, a SIP address, a destination looked up during the call or a phone book of up to 50 numbers, cold or warm16. Score: native booking, two CRMs, warm transfer with a summary and contact-center connections give 8.5.
Price 20%2.0No price is published. Synthflow sells only annual enterprise agreements with no free plan, no trial and no published per-minute rate3, and its sales page addresses teams handling 20K+ minutes a month17. The score rates what a small business can see and buy today; the actual cost stays unknown. Score: no published price gives 2.0.
Trust 10%9.0SOC 2 Type 2 report, ISO/IEC 27001 certification, PCI DSS v4.0.1, a HIPAA BAA and a GDPR DPA, with US or EU hosting5; connected providers can process some requests outside the chosen region8. Synthflow says it does not train its models on customer conversations5. Per agent, recordings and transcripts can be switched off, call data deleted after 30 days and personal data redacted18, though redaction skips audio and is not 100% accurate5. Customers can set a greeting that tells callers they are talking to AI11. HIPAA is self-attested3. Score: SOC 2 Type 2, ISO 27001, a BAA and per-agent recording and deletion controls give 9.0.
Support 10%8.0Enterprise customers get a Customer Success Manager, a shared Slack channel and a ticket portal19, plus forward-deployed engineers where the agreement includes launch support3. The docs carry a dated changelog, last updated November 6, 20267, and a public status page20. Score: a Customer Success Manager and a shared Slack channel give 8.0.

Synthflow pricing

Synthflow pricing, checked 8 November 2026
PlanPriceNotes
EnterpriseNot published3Annual agreement scoped to call volume, phone system, integrations, security needs and launch support, priced after a scoping call. No free plan, no trial and no published per-minute rate.
Pro, Growth and AgencyNo longer sold21Earlier plans with a fixed concurrency limit. Existing workspaces keep their limits.

Strengths and weak spots

Strengths

  • Agents reply within half a second, let callers interrupt and keep up when callers switch language, according to Synthflow8.
  • Three transfer modes, including a warm transfer that plays an AI-generated call summary to the person who picks up16.
  • Built-in connections for Zoom, Five9, RingCentral, 8x8, Twilio, Telnyx, Vonage and Freshcaller, so a business keeps its numbers and carrier8.
  • SOC 2 Type 2 report, ISO/IEC 27001 certification, a HIPAA BAA for customers who use its HIPAA Setting, and US or EU data hosting5.
  • Per-agent switches turn off recordings or transcripts, delete call data after 30 days and redact card numbers and other personal data from transcripts18.

Weak spots

  • No published price or per-minute rate, no free plan and no trial; every new deployment starts on an annual Enterprise contract3.
  • The earlier Pro, Growth and Agency plans are no longer sold21.
  • Going live takes weeks after a scoping call3; Batteries Plus took five weeks from kick-off to pilot13.
  • The built-in real-time booking action supports only Cal.com and GoHighLevel14; other systems are reached through custom HTTP actions15.
  • HIPAA compliance is self-attested3, and the SOC 2 report has to be requested through the Trust Center, where most documents need an access request and an NDA522.

Alternatives to Synthflow

Head to head

Synthflow: common questions

Does Synthflow have a free trial or per-minute pricing?

No. Synthflow has no free plan or trial and publishes no per-minute rate3. It sells an annual enterprise agreement scoped to call volume, phone system, integrations, security needs and launch support, and prices each deployment after a scoping call4. Calls are measured per second23, and each agreement sets a minute allocation and any rate per extra minute24.

Can a small business use Synthflow?

Only on an Enterprise contract. Synthflow's pricing page says it is built for mid-market and enterprise teams and that every new deployment starts on one3. Its sales page sends teams handling 20K+ minutes a month to sales and offers smaller teams a video demo to watch right away17. The earlier Pro, Growth and Agency plans are no longer sold21.

Can a Synthflow agent transfer a caller to a person?

Yes. The call transfer action sends a call to a phone number, a SIP address, a destination looked up during the call, or a phone book of up to 50 numbers16. A warm transfer plays a short message or an AI-generated summary to the person before connecting, and a cold transfer hands the call straight over16.

Sources

  1. Synthflow (AgentFlow AI GmbH). Imprint | Synthflow. Checked 8 Nov 2026.
  2. Synthflow (AgentFlow AI GmbH). About Synthflow. Checked 8 Nov 2026.
  3. Synthflow (AgentFlow AI GmbH). AI Voice Agent Pricing for Enterprise | Synthflow. Checked 9 Nov 2026.
  4. Synthflow (AgentFlow AI GmbH). Synthflow Facts: Enterprise AI Voice Agent Platform (last updated November 7, 2026). Checked 8 Nov 2026.
  5. Synthflow (AgentFlow AI GmbH). Voice AI Security and Compliance: SOC 2, HIPAA | Synthflow (last reviewed November 5, 2026). Checked 9 Nov 2026.
  6. Synthflow Docs (docs.synthflow.ai). Data Region | Synthflow. Checked 9 Nov 2026.
  7. Synthflow Docs (docs.synthflow.ai). Changelog | Synthflow. Checked 8 Nov 2026.
  8. Synthflow (AgentFlow AI GmbH). Enterprise AI Voice Agents for Phone Calls | Synthflow. Checked 9 Nov 2026.
  9. Synthflow Docs (docs.synthflow.ai). Voice Configuration | Synthflow. Checked 8 Nov 2026.
  10. Synthflow Docs (docs.synthflow.ai). Call Quality | Synthflow. Checked 8 Nov 2026.
  11. Synthflow Docs (AgentFlow AI GmbH). AI Transparency Statement | Synthflow. Checked 8 Nov 2026.
  12. Synthflow Docs (docs.synthflow.ai). Create an Agent | Synthflow. Checked 8 Nov 2026.
  13. Synthflow (customer story). Batteries Plus Runs AI Voice Agents on Zoom Phone | Synthflow. Checked 9 Nov 2026.
  14. Synthflow Docs (docs.synthflow.ai). Real-Time Booking | Synthflow. Checked 9 Nov 2026.
  15. Synthflow Docs (docs.synthflow.ai). Actions | Synthflow. Checked 8 Nov 2026.
  16. Synthflow Docs (docs.synthflow.ai). Call Transfers | Synthflow. Checked 9 Nov 2026.
  17. Synthflow (AgentFlow AI GmbH). Let's Talk About Your Voice AI Agent. Checked 8 Nov 2026.
  18. Synthflow Docs (docs.synthflow.ai). Security & Compliance | Synthflow. Checked 8 Nov 2026.
  19. Synthflow Docs (docs.synthflow.ai). Getting support | Synthflow. Checked 9 Nov 2026.
  20. Synthflow. Synthflow AI Status Page. Checked 8 Nov 2026.
  21. Synthflow Docs (docs.synthflow.ai). Concurrency | Synthflow. Checked 8 Nov 2026.
  22. Synthflow (hosted on SafeBase). Synthflow AI Trust Center. Checked 8 Nov 2026.
  23. Synthflow Docs (docs.synthflow.ai). Usage and Billing | Synthflow. Checked 8 Nov 2026.
  24. Synthflow Docs (docs.synthflow.ai). Billing Overview | Synthflow. Checked 9 Nov 2026.