Synthflow alternatives for agencies: five ways forward, including staying put.
CompareBy CenterfyUpdated
The short answer
You have five realistic paths. Stay on Synthflow and bill clients from your own Stripe account, which is a legitimate choice if the agents work and your billing is simple. Move to Centerfy if you want rebilling, client sub-accounts, white labelling and a CRM in one platform, with the team building the agents for you. Use HighLevel's native Voice AI if your agency lives in HighLevel and you will configure it yourself. Or build on Retell AI or Vapi if you have a developer and want to own the call flow; check how you would bill clients before you start. Centerfy publishes this comparison and is one of the options.
What an agency actually needs to replace
Synthflow gave resellers five things in one product: the voice agents, a separate workspace for each client, your brand on the platform, caps on what each client can use, and billing. On September 15, 2026 the fifth was removed. The other four still work. So the question is narrower than “which voice platform is best”. It is where you want client billing to live, and how much of your setup you are willing to rebuild to get it there.
Five paths at a glance
Descriptions summarise each vendor's public documentation as of November 2026 and link to it under Sources. Confirm anything that matters to you with the vendor before you move.
| Path | What it is | Best fit | Confirm before you commit |
|---|---|---|---|
| Stay on Synthflow, bill externally | Keep agents, subaccounts, branding and limits where they are. Charge clients from your own Stripe account and track minutes through Synthflow's API or webhook. | Agencies whose agents work well and whose billing is simple, or who have a developer for usage billing. | Your own contract terms, and who covers overage when a client passes their cap. |
| Centerfy | AI voice and chat agents built for you, plus a standalone CRM that natively integrates with GoHighLevel. The White Label plan adds a branded agency workspace, client sub-accounts and rebilling through your own Stripe account. | Agencies that want billing, agents and CRM in one platform and do not want to build a billing layer. | Agents are rebuilt, not imported. Per-client minute caps, if you rely on them. |
| HighLevel Voice AI | HighLevel's native voice agent, configured inside the CRM on LC Phone or Twilio numbers. HighLevel documents rebilling for its AI products. | Agencies that already run on HighLevel and want voice inside it with no third party. | The HighLevel plan that rebilling requires, outbound availability and per-minute pricing. |
| Retell AI | AI voice agent platform with a GoHighLevel integration that Retell builds and maintains itself. | Teams with a developer who want to own the call flow. | How you would give each client a workspace and bill them, and who maintains the flows. |
| Vapi | Voice agent platform with documented GoHighLevel tools for contacts and calendar booking. | Technical teams that want deep control of the voice stack. | The same: client workspaces, branding and billing, plus total cost across the voice, speech and model components. |
Staying on Synthflow is a real option
It would be easy for a competitor to tell you to leave. Often you should not. If your agents are tuned, your clients are happy and you bill a flat monthly fee, the removal costs you a session in Stripe to recreate subscriptions and a pass through Limits & Capabilities. Synthflow's documentation confirms that subaccounts, permissions, branding, custom domains and products all continue to work.
Staying gets harder in three situations:
- You bill by the minute. You now need a usage feed, a billing system and a monthly reconciliation. See Replacing Synthflow rebilling.
- Clients expect to see their usage. The Plan & Billing and Usage pages were removed from subaccounts, so a client portal is yours to build.
- You are signing a new agreement. Synthflow's pricing page, read on November 5, 2026, says the product is sold as an annual enterprise agreement, with no free plan or trial and no rate by the minute, and that white label is available within that agreement. If you are an existing customer, your own agreement governs, not the public page. Ask your account team what applies to you.
How to choose in a week
- Billing model. Flat fee, or by the minute? Flat fees are easy to run from Stripe on any platform. Billing by the minute needs metering, and it is the main reason to prefer a platform that does it for you.
- Who does the work. A developer platform moves the build, the billing layer and the maintenance to you or a contractor. A done-for-you provider keeps them off your desk.
- Client workspaces and brand. List what each client logs in to today. Check that the replacement gives each client a separate workspace under your logo and domain.
- Phone numbers. Find out which carrier account each number is in before you compare anything else. See Keeping control of client phone numbers.
- GoHighLevel. If your clients run on GoHighLevel, test the connection end to end: contact, tags, notes, appointment. See Synthflow and GoHighLevel.
- Total cost. Add the platform fee, per-minute rates, per-message rates, number rental and the hours you spend on billing each month. Compare the same expected minutes on each.
Why agencies pick Centerfy
- Rebilling is built in. Connect your own Stripe account, set a monthly price and per-usage rates for each client, and Centerfy calculates the charges. Your clients are billed by your agency; Centerfy does not appear on their invoices.
- Built for you. You do not have to learn a new builder. Centerfy's team sets the agents up from your prompts and business details, and White Label comes with a dedicated account manager.
- Your brand. Your logo, colours and domain on the workspace, and a sub-account for each client.
- GoHighLevel stays. Centerfy is a standalone CRM that natively integrates with GoHighLevel, and the White Label plan installs into your own GoHighLevel agency.
- Numbers come with you when they are in a Twilio or Telnyx account you control.
- Price match. Centerfy matches or beats any competitor's price on comparable AI agent software; show the offer.
- Hear it first. Call Julie, the Centerfy demo agent, on +1 (650) 316-9306, or talk to her on the homepage.
Centerfy's current plan prices and usage rates, as published on the pricing page:
| Plan | Per month | AI calls | AI chat | Includes |
|---|---|---|---|---|
| Starter | $148.50$297 | $0.14/min | $0.02/msg | One business, fully automated. |
| Unlimited | $248$497 | $0.10/min | $0.02/msg | Every location, no caps. |
| White Label | $497$997 | $0.07/min | $0.02/msg | Resell AI under your brand. |
Frequently asked questions
What is the best Synthflow alternative for agencies?
Should I leave Synthflow?
Which alternatives have rebilling built in?
Which alternatives work with GoHighLevel?
Do I need a developer?
Can I keep my phone numbers if I move?
How much does Centerfy cost compared with Synthflow?
Is this an independent comparison?
Sources
- 1.Synthflow documentation: Reselling Synthflow's own account of the removal: what stopped on September 15, 2026, who is affected, what stays the same, and how to track and bill subaccounts now. Read on November 5, 2026.
- 2.Synthflow documentation: Stripe States that the Stripe integration for reselling was removed, that connected accounts were disconnected, and that agencies can still run subaccounts without it. Read on November 5, 2026.
- 3.Synthflow documentation: Limits & Capabilities Included minutes, auto-overage and who pays for it, concurrent calls, agent and workflow limits. Read on November 5, 2026.
- 4.Synthflow pricing page States that Synthflow is sold as an annual enterprise agreement with no free plan or trial and no rate by the minute, and that white label is available within that agreement. Describes new agreements, not existing accounts. Read on November 5, 2026.
- 5.Synthflow documentation: Billing Overview States that Synthflow no longer bills subaccounts, and that existing workspaces are governed by their own agreement rather than public documentation. Read on November 5, 2026.
- 6.Centerfy help centre: billing and rebilling Connecting your own Stripe account, per-sub-account rebilling, the usage types you can price, default rates and usage tracking.
- 7.Centerfy help centre: white label Logo, favicon, colours, custom domain, SMTP email, custom CSS, JavaScript and menu links.
- 8.HighLevel help centre: overview of Voice AI agents HighLevel's own documentation for its native Voice AI agents, including the LC Phone or Twilio number requirement. Read on November 5, 2026.
- 9.HighLevel help centre: AI Employee access, rebilling and reselling HighLevel's documentation for rebilling its AI products, including Voice AI, to sub-accounts. Read on November 5, 2026.
- 10.Retell AI: GoHighLevel integration Vendor page. Read on November 5, 2026.
- 11.Vapi: GoHighLevel tools Vendor documentation. Read on November 5, 2026.
Centerfy publishes this guide and offers an alternative to Synthflow. Synthflow is an operating company; statements about it are limited to the sources above, read on the dates given, and its product may have changed since. Descriptions of other vendors summarise their public documentation. Source: https://centerfy.ai/resources/synthflow/alternatives