Synthflow pricing (2026): enterprise-only plans, what's published, and how to budget a 10,000-minute month

Synthflow no longer publishes self-serve tiers. Its pricing page shows one plan, Enterprise, and one number: "Enterprise contracts start at $30,000 annually." There is no per-minute rate, monthly plan, included-minute block, or free trial on the page (Synthflow pricing, accessed 2026-09-08). This guide covers what is public, how usage is metered, and what to get from sales before budgeting a 10,000-minute month.

How Synthflow's pricing model works

The pricing page is a single card. Its full pricing statement reads: "Enterprise contracts start at $30,000 annually. Final pricing is scoped around call volume, concurrency, telephony setup, integrations, security needs, and launch support." The call to action is "Contact Sales" (Synthflow pricing, accessed 2026-09-08).

The documentation is blunter: "Synthflow uses sales-led pricing," and existing customers should "not use public documentation as a quote" (Synthflow billing overview, accessed 2026-09-08). The Enterprise page calls it a "Sales-led annual agreement" with allowances, carryover, or overage terms "when included in the agreement" (Synthflow Enterprise docs, accessed 2026-09-08).

Older tiers survive for existing customers only: "Earlier Pro, Growth, and Agency plans were issued with fixed concurrency limits. These plans are no longer available for new subscriptions" (Synthflow concurrency docs, accessed 2026-09-08).

What's included vs. billed separately

Sources: pricing, usage docs, Enterprise docs, concurrency docs, homepage, accessed 2026-09-08.

What Synthflow does publish in detail is the metering. Calls are "measured per second, starting when the human and the AI agent connect," partial seconds round up, and seconds pool across calls so that "four calls totaling 125 seconds produce 2 reported usage minutes." Calls with a no-answer or hangup_on_voicemail status "are recorded as a flat 5 seconds of usage"; failed or user-canceled calls "are not billed" (Synthflow usage docs, accessed 2026-09-08).

Worked example: 10,000 minutes a month

Take the standard workload used across these guides: 2,000 calls × 5 connected minutes = 10,000 connected minutes per month, or 120,000 minutes a year.

There is no computable Synthflow total for this workload. The pricing page publishes no per-minute rate and no allowance, so nothing can be multiplied. What is computable is the floor, and only as an illustration:

Annual floor: $30,000 per year

Monthly equivalent: $30,000 ÷ 12 = $2,500 per month

Floor spread over the workload: $30,000 ÷ 120,000 minutes = $0.25 per minute — only if the included allowance were exactly 120,000 minutes at exactly the floor price

Both conditions are unknown: more included minutes would lower the effective rate; fewer would add overage at an unpublished rate. The $0.25 figure is arithmetic on the floor, not a Synthflow price.

Before this month can be budgeted, a buyer needs from sales: the included allowance per period and whether carryover applies; the overage rate; whether telephony and international routes sit inside the rate; the concurrency and CAPS limits, since excess calls "can return a 429 HTTP error or be queued briefly"; and invoice timing, because some accounts invoice "when configured usage thresholds are reached" and "Thresholds are triggers, not caps" (Synthflow usage docs, concurrency docs, accessed 2026-09-08).

Gotcha checklist

• The only public number is a floor. $30,000 a year is where contracts "start," not what a 10,000-minute month costs.
• Legacy plans are closed. Pro, Growth, and Agency "are no longer available for new subscriptions."
• Threshold invoices can exceed the threshold. Checks "may not be evaluated in real time," so "the invoice amount may be higher than the configured threshold."
• Chat, simulations, and unanswered calls consume minutes. Five AI chat messages equal one usage minute; simulations "may count messages from both the agent and the simulated counterpart"; no-answer and voicemail-hangup calls bill a flat 5 seconds each.
• Reseller billing is being removed. "In-product reselling through Stripe will be removed on September 15, 2026" (Synthflow custom pricing docs, accessed 2026-09-08).

How ThunderPhone prices differ

ThunderPhone publishes one all-in per-minute engine rate — speech recognition, language model, and voice included — pay as you go with no subscription, seat fee, annual commitment, or contract floor: Spark 2¢/minute, Bolt 5¢/minute, Storm 9¢/minute (unpacked in ThunderPhone pricing explained). The same 10,000-minute month computes directly:

Spark: 10,000 × $0.02 = $200

Bolt: 10,000 × $0.05 = $500

Storm: 10,000 × $0.09 = $900

Illustrative arithmetic: premium voice or language paths add up to 3¢/minute, hold bills a flat 2¢/minute, and telephony depends on setup.

The honest flip side: Synthflow's contract bundles things a per-minute rate does not — a contracted SLA, an enterprise security review, MSA/DPA support, and an implementation team for onboarding, testing, and launch. A regulated contact center that needs those services delivered by the vendor, with named support and negotiated terms, may find the $30,000 floor is buying the right thing. ThunderPhone is GDPR and HIPAA compliant — its published pricing lists no compliance add-on fee — and customers remain responsible for configuring their workflows, data handling, recordings, and notices for their own obligations.

FAQ

How much does Synthflow cost?

Enterprise contracts "start at $30,000 annually," and no other price is published. Final pricing is scoped to volume, concurrency, telephony, integrations, security, and launch support. Synthflow pricing, accessed 2026-09-08.

Does Synthflow have a per-minute rate or a free plan?

Not on its public pages. The docs say "Enterprise customers have custom rates, allowances, and invoice terms based on their agreement." Synthflow usage docs, accessed 2026-09-08.

What would 10,000 minutes a month cost on Synthflow?

It cannot be computed from published numbers. The $30,000 floor is $2,500 a month, or $0.25 per minute only if the allowance were exactly 120,000 minutes a year. ThunderPhone's published rates put the same workload at $200, $500, or $900 by engine, illustratively.

How does Synthflow count minutes?

Per second, pooled across calls, from connection until the call ends or a transfer completes. No-answer and voicemail-hangup calls bill a flat 5 seconds; failed and user-canceled calls are not billed. Synthflow usage docs, accessed 2026-09-08.

Sources and freshness

All Synthflow claims were checked on September 8, 2026 against the pricing page, homepage, ROI calculator (which publishes no Synthflow rate), and the billing, usage, Enterprise, concurrency, custom pricing, and manage subscription docs. ThunderPhone pricing reflects its published pricing and documentation as of September 1, 2026. This guide is documentation-based — no Synthflow account, invoice, quote, or live call was tested. Compliance lists differ by page (docs: SOC2, GDPR, ISO 27001; homepage: SOC 2, HIPAA, PCI DSS, GDPR), and the "starting at" floor is the only public price, so any per-minute figure derived from it is an illustration.