Quick answer: As at 31 October 2026, Synthflow, the voice AI agent platform at synthflow.ai, publishes no plan price and no per-minute rate. Its pricing page sells one thing, an annual enterprise agreement, with “no free plan or trial and no rate by the minute”. The only dollar figure in its pricing and billing pages is US$1.50 a month per test phone number. The “$30,000 annually” starting price has been taken off the page.
This page is about Synthflow, the Berlin-registered company (AgentFlow AI GmbH) that sells AI voice agents for phone calls, not any other product with a similar name. Everything below comes from Synthflow’s own pricing page, its documentation at docs.synthflow.ai, its changelog and its published terms, all read on 31 October 2026, plus dated Wayback Machine copies of the pricing page. Where Synthflow publishes nothing, we say so and name the pages we checked.
How much does Synthflow cost?
Synthflow does not print a monthly fee, a per-minute rate, an included-minute allowance or a plan list. Its pricing page, titled “AI Voice Agent Pricing for Enterprise”, says Synthflow “is sold as an annual enterprise agreement, scoped to your call volume, phone system, integrations, security needs and launch support”, and that “every new deployment starts on an Enterprise contract”. Its billing documentation says the same thing in four words: “Synthflow uses sales-led pricing.” It also warns existing customers: “do not use public documentation as a quote”.
So the honest answer to “how much is Synthflow AI” is that the figure exists only in your Order Form. What Synthflow does publish is how the bill is built: which units are metered, how minutes are counted, what is non-refundable, and what it scopes. That is enough to estimate your billed minutes before the sales call, and to know what to ask for in writing. The table sets out every price element a buyer usually looks for and what Synthflow’s own pages say about each one.
| Price element | What Synthflow’s own page says, as at 31 October 2026 | Where it says it |
|---|---|---|
| Plans and plan names | One product: an Enterprise contract. “Is There an Agency Plan? No.” The earlier Pro, Growth and Agency plans “are no longer sold, and existing workspaces keep their limits.” | Pricing page FAQ; Concurrency doc |
| Monthly fee | Not published. Sold as an annual agreement. | Pricing page |
| Per-minute rate | Not published: “no rate by the minute”. Rates sit in your agreement; the Plan & Billing screen shows “the rate per extra minute” for your own workspace. | Pricing page; Billing Overview |
| Included minutes | Not published. Allowances, carryover and overage apply “when included in the agreement”. | Enterprise doc |
| Free plan or trial | None: “no free plan or trial”. | Pricing page |
| Concurrency | No number published for new customers. Concurrency and calls-per-second limits are “Scoped with Synthflow” and shown in Plan & Billing. | Concurrency doc |
| White-label and agency | No separate tier. “BPOs and software platforms can add white-label in that contract.” In-product reselling through Stripe was removed on 15 September 2026. | Pricing page FAQ; Billing Overview |
| Telephony | Scoped into the contract: “Synthflow Native Telephony, SIP trunking, or approved enterprise telephony”. SIP/PBX connection “requires an Enterprise plan subscription”. International calling “can vary by destination, carrier path, and telephony setup”. | Pricing page; Telephony doc; Usage doc |
| Phone numbers | US$1.50 a month per number bought in Synthflow, for US, Canadian and Australian numbers, offered “for quick testing”. Deleting the number cancels its subscription. | Phone Numbers doc |
| LLM and voice | No separate public rate. Since 25 August 2026, non-enterprise accounts run only on Synthflow LLM; “Enterprise accounts are unaffected”. The usage dashboard breaks cost down “by provider, such as LLM, voice engine”. | Changelog, 25 Aug 2026; Usage doc |
| Annual discount | Not applicable as published: the only product is annual. No monthly-versus-annual comparison is printed. | Pricing page |
| Currency and tax | “Billing is processed in USD”, with other currencies possible for Enterprise. EU customers are told to add a VAT number “to avoid being charged additional VAT”; ABN is a supported tax ID. | Manage Your Subscription doc |
| Refunds and cancellation | US enterprise terms: fees “are non-refundable” unless the terms or Order Form say otherwise. Self-serve billing portal: no refunds “for partial billing periods”. Detail in the terms section below. | GTC – Direct Use (US); Manage Your Subscription doc |
The single quotable line: as at 31 October 2026, the only Synthflow price we found on Synthflow’s own pricing page and billing documentation is US$1.50 a month for a test phone number; everything else is set per contract.
What happened to Synthflow’s $30,000 starting price?
Until October 2026, Synthflow’s pricing page did print one figure. Archived copies of the page captured on 6 July, 3 September, 29 September and 14 October 2026 all read: “Enterprise contracts start at $30,000 annually. Final pricing is scoped around call volume, concurrency, telephony setup, integrations, security needs”. The archived copy captured on 29 October 2026, and the live page we read on 31 October 2026, no longer contain that sentence. The live page’s server reports it was last modified on 29 October 2026.
A further archived copy captured on 22 October 2026 still carried it, so the figure came off between 22 and 29 October; we cannot say exactly when, and Synthflow’s changelog has no entry about it. What we can say is that a buyer should not treat $30,000 a year as Synthflow’s current floor, and should not treat it as a ceiling either. The page now gives no anchor in either direction. If a sales conversation produces a minimum commitment, it will be in your Order Form; Synthflow’s Enterprise doc answers its own question “What’s the minimum commitment for Enterprise?” with “Enterprise terms are defined in your agreement.”
Several other pricing-relevant changes landed in the last 90 days, all from Synthflow’s own changelog and docs:
| Date (2026) | Change | What it means for cost |
|---|---|---|
| 29 July (notice) | “Stripe-based reselling is ending”: custom pricing plans for subaccounts to end on 15 September | Agencies must bill their own customers outside Synthflow |
| 25 August | “Non-enterprise plans now run on Synthflow LLM”; GPT models no longer available on those plans | Model choice on legacy plans is fixed; Enterprise unaffected |
| 15 September | In-product reselling removed; “Synthflow no longer bills your subaccounts” | No in-product rebilling for agencies |
| 17 September | “Auto-overage for subaccounts”: extra minutes “billed to your account at your per-minute rate” | A parent account can remove a subaccount’s spend ceiling |
| Between 22 and 29 October | “$30,000 annually” removed from the pricing page; page now says “no rate by the minute” | No public floor or rate remains |
Where Zian fits
If you are pricing Synthflow because you want AI agents that answer and make your calls, put Zian beside it: Zian is an AI sales and reception agents platform that answers inbound calls 24/7 as an AI receptionist and runs outbound follow-up by voice, SMS, email, WhatsApp, Instagram DMs and Facebook Messenger. Like Synthflow, Zian prints no price today, because it is in partnership-application beta and each of its three listed plans, including Intel + Widgets (Free Forever), starts with a partnership application.
The difference is what you are buying. Synthflow scopes a contract for a platform your team builds on. Zian’s agents qualify, book, transfer and take messages on inbound calls, handle answering machines and voicemail on outbound calls, and work in 30+ languages with voice cloning, CRM and API integrations (HubSpot, Salesforce, HighLevel, Zapier) and private model deployment on customer infrastructure. SmartReach AI™ sets the message, channel, timing and follow-up pacing, and PrecisionPitch AI™ keeps split-testing scripts against real outcomes. Zian’s live counter shows 50,769+ qualified sales appointments set.
If you would rather not run any platform yourself, LeadsNow.ai is the done-for-you option: a managed AI appointment setting and lead generation service that runs on Zian, priced on a pay-per-result basis, with leads answered in under 60 seconds, 24/7.
Want the receptionist and the outbound follow-up on one platform? Zian is in partnership-application beta. Apply For Partnership
What you are billed for on Synthflow
Because the rate is private, the useful public fact is the meter. Synthflow’s US enterprise terms say usage “shall be measured in accordance with Synthflow’s then-current metering methodology, published at” its Usage and Billing page, with per-unit rates in the Order Form, which “shall prevail in the event of any inconsistency”. That makes the Usage and Billing page part of the price. These are its definitions.
| Billable unit or term | How Synthflow defines or measures it |
|---|---|
| Call usage | Measured per second, “starting when the human and the AI agent connect and ending when the call terminates”. Partial seconds round up to the next second. |
| Billed minutes | Seconds are pooled across calls, not rounded per call. Each whole minute that accumulates is reported on the invoice; leftover seconds carry to the next call. Synthflow’s own example: four calls of 30, 45, 20 and 30 seconds (125 seconds) report 2 minutes with 5 seconds carried. |
| Unanswered calls | “no-answer” and “hangup_on_voicemail” are “recorded as a flat 5 seconds of usage”. |
| Calls not billed | “failed” and “user-canceled” are not billed. Since 16 June 2026, a call the caller ends within the first second, before the agent answers, reports as user-canceled. |
| Voicemail left | “left_voicemail” is measured per second, like a completed call. |
| Transfers | If a transfer completes, billable AI usage stops at the point of transfer. |
| Chat and SMS | “every 5 AI-generated messages count as 1 usage minute”, at the rate in your agreement. |
| Simulations | Test Center simulations “can be measured separately” and may count messages from both sides, depending on workspace configuration. |
| Allowance and overage | Plans with an allowance “only charge for usage above that allowance”. Auto-overage, where on, keeps calls running past the allowance at your per-minute rate. |
| Carryover | Unused included minutes roll forward only “when included in your agreement”. |
| Threshold invoices | An invoice can be raised when unbilled usage hits a set threshold. “Billing thresholds are triggers, not spending caps”, and the invoice can exceed the threshold. |
| Phone numbers | US$1.50 a month per purchased number, billed as a subscription per number. |
Two of those rows matter most for outbound budgets. Unanswered calls are cheap but not free: 1,000 no-answers add 5,000 seconds, or 83 billed minutes. And pooling seconds rather than rounding each call up is a genuine saving against vendors that bill by the started minute. For how other platforms treat calls nobody picks up, see our explainer on whether you are charged for AI calls nobody answers.
Synthflow cost worked at 2,000, 10,000 and 50,000 calls a month
Without a public rate, the worked example prices minutes, not dollars. We ran Synthflow’s published metering rules through a short script at three outbound volumes, then show what each US cent of your contracted per-minute rate is worth at that volume. Substitute your own quote and multiply.
The outcome mix below is our assumption for a typical outbound list, not Synthflow’s data. Change it to match your own call logs. We did not model “busy” calls, which Synthflow measures per second.
| Input (our assumption) | Share of dials | Billable seconds per call (Synthflow rule) |
|---|---|---|
| Completed conversation | 30% | 150 (per second) |
| Voicemail left by the agent | 10% | 30 (per second) |
| Hung up on voicemail | 15% | 5 (flat) |
| No answer | 35% | 5 (flat) |
| Failed | 7% | 0 (not billed) |
| User-canceled | 3% | 0 (not billed) |
| Result per month | 2,000 dials | 10,000 dials | 50,000 dials |
|---|---|---|---|
| Billable seconds | 101,000 | 505,000 | 2,525,000 |
| Billed minutes (seconds pooled) | 1,683 (20 s carried) | 8,416 (40 s carried) | 42,083 (20 s carried) |
| Of which from unanswered calls | 83.3 (5.0%) | 416.7 (5.0%) | 2,083.3 (5.0%) |
| Connected calls, pooled | 1,600 | 8,000 | 40,000 |
| Connected calls if rounded up per call, for comparison | 2,000 | 10,000 | 50,000 |
| Billed minutes over 12 months | 20,200 | 101,000 | 505,000 |
| Each US$0.01 of per-minute rate, per month | US$16.83 | US$84.16 | US$420.83 |
| Each US$0.01 of per-minute rate, per year | US$202.00 | US$1,010.00 | US$5,050.00 |
The arithmetic for the middle column: 3,000 completed calls at 150 seconds is 450,000 seconds; 1,000 voicemails at 30 seconds is 30,000; 1,500 voicemail hang-ups and 3,500 no-answers at a flat 5 seconds are 7,500 and 17,500; failed and cancelled calls add nothing. That is 505,000 seconds, or 8,416 whole minutes with 40 seconds carried. At 150 seconds, a completed call is 2.5 minutes pooled but would be 3 if rounded up per call, which is why pooling bills 20% fewer connected minutes than per-call rounding would (8,000 against 10,000).
The quotable figure: on Synthflow’s published metering, a 10,000-dial month with this mix bills about 8,416 minutes, so every US cent on your contracted rate moves the bill by about US$84 a month, or US$1,010 a year. Text channels add to that at 5 AI messages per minute: 1,000 SMS conversations of 6 AI messages each come to 6,000 messages, or 1,200 usage minutes.
Your dollar total is billed minutes multiplied by whatever per-minute rate your agreement sets, plus anything the agreement adds for concurrency, telephony, integrations or launch support. The one rendered Synthflow page where we found a per-minute cost figure in use is its ROI calculator: as at 31 October 2026, the page’s own script works out its “Synthflow Investment” line as the monthly call minutes you enter × 12 × 0.15, in whichever currency you select. Synthflow labels the result “Illustrative estimate only” and says it “does not constitute a contractual commitment”, so treat 0.15 as Synthflow’s modelling assumption, not a quote. On that assumption, the 10,000-dial month above (8,416 billed minutes) would come to about US$1,262. For the components that usually sit inside a per-minute voice price, see our breakdown of voice AI cost per minute for realtime and pipeline stacks.
Refunds, unused minutes and cancellation in Synthflow’s terms
Synthflow publishes two sets of terms, and which applies depends on how you buy. New customers sign an Enterprise Order Form; Synthflow publishes General Terms and Conditions for direct enterprise use, with a United States version and a DACH version. The US version (version 1.0, last updated 13 May 2026) says, in its Fees and Payment section: “Except as otherwise specified herein or in the applicable Order Form Fees paid are non-refundable and Usage Volume ordered cannot be decreased.” It adds that you pay the Order Form fees “for the whole contractual period”, whether or not you use the software, in the initial term or a renewal term. Unless the Order Form says otherwise, Synthflow invoices in advance at the start of each billing period.
On minutes, the same terms are more flexible within a period and stricter at its end. A monthly volume can be used across the whole billing period, and “No monthly caps or monthly minimum quotas shall apply, provided that the total Usage Volume is not exceeded”. But “Any unused Usage Volume shall expire at the end of the applicable Billing Period without any refund, credit, or other form of compensation”. Excess usage is paid at the rate agreed in the Order Form. Synthflow’s docs separately describe carryover as available only when your agreement includes it, so the Order Form is where that term has to be written.
Existing self-serve workspaces sit under different rules. The Subscriber Terms (version 1.0, last updated 13 May 2026, “Applicable to: Self-serve subscribers via synthflow.ai”) say usage limits are “defined per month and do not roll over to the next month”, that agreements renew automatically unless the plan says otherwise or either party terminates, and that “Unless agreed otherwise” either party may terminate “with 3 months’ notice in text form (email is sufficient)”, to the end of a fixed term or at any time for an unlimited term. Synthflow may raise fees on three months’ notice, and you may object, in which case the agreement ends at the end of the current term. Synthflow’s billing-portal doc, written for the same self-serve accounts, says you can cancel at any time, that cancellation “takes effect at the end of your current billing period”, and that refunds “are not issued for partial billing periods”. It tells Enterprise customers to contact their account manager instead.
The quotable line: on Synthflow’s US enterprise terms, unless your Order Form says otherwise, fees are non-refundable, ordered volume cannot be reduced, and unused volume expires at the end of the billing period.
Synthflow beside a beta platform and a done-for-you service
None of the three options below prints a per-minute rate you can multiply today, so the useful comparison is how each one gets you to a number. The Synthflow metering rules and closed legacy plans described here match our earlier comparison of Zian AI and Synthflow for outbound; since that page was checked on 4 September 2026, Synthflow has removed in-product reselling (15 September), added auto-overage for subaccounts (17 September) and taken its entry price off the pricing page (October).
| Option | How you buy it | Published price, as at 31 October 2026 |
|---|---|---|
| Zian (platform) | Partnership-application beta; each of its three listed plans, including Intel + Widgets (Free Forever), starts with a partnership application | No public price during beta |
| LeadsNow.ai (done-for-you) | Managed AI appointment setting and lead generation that runs on Zian | Pay-per-result; we do not print its price here |
| Synthflow (platform) | Annual enterprise agreement, scoped on a sales call | No per-minute rate or plan fee; US$1.50 a month per test number |
How to get a real Synthflow price quickly
Synthflow’s pricing page lists the five things it scopes a contract on. Bring a number for each and you shorten the sales cycle, because each one changes the quote. Use this scoping sheet, and ask for the matching term in the Order Form.
| Synthflow scopes on | Bring this number | Ask for this in writing |
|---|---|---|
| Call volume and concurrency | Monthly dials or inbound calls, average connected seconds, peak simultaneous calls | Per-minute rate, included volume, overage rate, concurrency and calls-per-second limits |
| Telephony and number ownership | Whether you use Synthflow numbers, your own Twilio account or a SIP trunk; destination countries | Telephony rate or pass-through, international rates by destination |
| Integrations | CRM, calendar and contact-centre systems the agent must write to | Which integrations are in scope and any build fee for Deliverables |
| Security and procurement | Your MSA, DPA and security-review requirements | Data region, support and availability terms |
| Launch support | Go-live date and who builds the agents | Whether forward-deployed engineers are included, and at what price |
Also ask three billing questions the public pages leave to the agreement: whether unused minutes carry over, whether auto-overage is on by default, and what invoice threshold, if any, applies to your account. Each is a line in Plan & Billing once you sign, and each can move the annual total by more than the per-minute rate does.
Synthflow pricing FAQ
How much does Synthflow cost per month?
Synthflow publishes no monthly price. As at 31 October 2026 its pricing page says it “is sold as an annual enterprise agreement” with “no free plan or trial and no rate by the minute”, so the monthly cost is whatever your Order Form sets. The only price on its pricing and billing pages is US$1.50 a month per test phone number; its ROI calculator models cost at 0.15 per minute but calls that “Illustrative estimate only”.
Does Synthflow have a free plan or free trial?
No. Synthflow’s pricing page answers “Is Synthflow Free to Use?” with “No. Synthflow has no free plan or trial and no rate by the minute.” Every new deployment starts on an Enterprise contract.
What happened to Synthflow’s $30,000 starting price?
It is no longer on the page. Archived copies of Synthflow’s pricing page from July to 22 October 2026 said “Enterprise contracts start at $30,000 annually”; the copy captured on 29 October 2026 and the live page on 31 October 2026 do not. Treat any minimum commitment as a term in your agreement.
Does Synthflow charge for unanswered calls?
Yes, a little. Synthflow’s Usage and Billing documentation says calls with a no-answer or hang-up-on-voicemail status “are recorded as a flat 5 seconds of usage”, while failed and user-canceled calls are not billed. So 1,000 unanswered calls add 5,000 seconds, about 83 billed minutes.
Is telephony included in Synthflow’s price?
It is scoped into the contract. Synthflow’s pricing page says the contract covers “Synthflow Native Telephony, SIP trunking, or approved enterprise telephony”, SIP and PBX connections need an Enterprise plan, and numbers bought in Synthflow cost US$1.50 a month each. International rates depend on destination, carrier path and setup.
Is there a Synthflow agency or white-label plan?
Not as a separate plan. Synthflow’s pricing page says “Is There an Agency Plan? No.” and that BPOs and software platforms “can add white-label in that contract”. In-product reselling through Stripe was removed on 15 September 2026.
Can I cancel Synthflow and get a refund?
Generally not a refund. Synthflow’s US enterprise terms say fees “are non-refundable” and are owed for the whole contractual period unless the Order Form says otherwise, and unused volume expires at the end of the billing period. Self-serve accounts can cancel from the billing portal, effective at the end of the period, with no refunds for partial periods.
Where every figure on this page comes from
| Figure | Who published it | Link | Date read |
|---|---|---|---|
| “no free plan or trial and no rate by the minute”; annual enterprise agreement; no agency plan; white-label in contract; telephony options | Synthflow | synthflow.ai/pricing | 31 October 2026 |
| “Enterprise contracts start at $30,000 annually” (former wording) | Synthflow, archived by the Internet Archive | Wayback capture, 22 October 2026 | 31 October 2026 |
| $30,000 figure absent | Synthflow, archived by the Internet Archive | Wayback capture, 29 October 2026 | 31 October 2026 |
| Sales-led pricing; Plan & Billing sections; reselling removed 15 September 2026 | Synthflow | docs.synthflow.ai/billing | 31 October 2026 |
| Per-second metering; pooled minutes; 125 seconds = 2 minutes example; flat 5 seconds; 5 messages = 1 minute; threshold invoices | Synthflow | docs.synthflow.ai/usage | 31 October 2026 |
| Sales-led annual agreement; allowances, carryover, overage per agreement | Synthflow | docs.synthflow.ai/enterprise | 31 October 2026 |
| US$1.50 a month per purchased number; US, Canada, Australia | Synthflow | docs.synthflow.ai/phone-numbers | 31 October 2026 |
| Billing in USD; cancellation at period end; no refunds for partial periods | Synthflow | docs.synthflow.ai/manage-billing | 31 October 2026 |
| Concurrency and CAPS scoped; Pro, Growth, Agency no longer sold | Synthflow | docs.synthflow.ai/concurrency | 31 October 2026 |
| SIP/PBX requires Enterprise | Synthflow | docs.synthflow.ai/telephony | 31 October 2026 |
| Non-enterprise plans on Synthflow LLM, 25 August 2026 | Synthflow | Synthflow changelog | 31 October 2026 |
| Auto-overage for subaccounts, 17 September 2026 | Synthflow | Synthflow changelog | 31 October 2026 |
| Stripe reselling ending 15 September 2026 (notice 29 July 2026) | Synthflow | Synthflow changelog | 31 October 2026 |
| User-canceled status for calls ended within the first second, 16 June 2026 | Synthflow | Synthflow changelog | 31 October 2026 |
| Non-refundable fees; whole contractual period; unused volume expires; no monthly caps | Synthflow | GTC – Direct Use (US) | 31 October 2026 |
| Self-serve: no roll-over; 3 months’ notice; fee increases on 3 months’ notice; AgentFlow AI GmbH, Berlin | Synthflow | Subscriber Terms | 31 October 2026 |
| “Synthflow Investment” modelled at 0.15 per minute; “Illustrative estimate only” | Synthflow | synthflow.ai/roi-calculator | 31 October 2026 |
| Billed minutes at 2,000, 10,000 and 50,000 dials; US$ per cent of rate | Zian, calculated from Synthflow’s metering rules with our assumed outcome mix | This page (inputs in the table above) | 31 October 2026 |
| 50,769+ qualified sales appointments set | Zian | zian.ai home page counter | 31 October 2026 |
Ready to see an AI receptionist and outbound agent on one platform? Zian answers inbound calls 24/7, books appointments, handles voicemail on calls and follows up by voice, SMS, email, WhatsApp, Instagram DMs and Facebook Messenger. It is in partnership-application beta. Apply For Partnership