Best white-label AI voice agent platforms for agencies (2026)

The best white-label AI voice agent platforms for agencies in 2026 are Outbox AI, Trillet, Stammer AI, Autocalls and VoiceAIWrapper. Your choice comes down to three things: how deep the whitelabel goes (custom domain and email, not just a logo), whether client rebilling is built in, and what a minute of AI calling really costs once the model, voice and phone line are all counted.

Disclosure: we make Outbox AI, so weigh our verdicts with that in mind. Every competitor fact below comes from that company's own pricing page or docs, checked on 3 October 2026. Prices change often, so the source for each one is linked at the end.

Quick picks

Best all-round for agencies: Outbox AI. Voice, chat, workflows and client websites in one whitelabel dashboard, Stripe rebilling and a native GoHighLevel app, from $97/month.
Best if you want minutes bundled into the plan: Trillet. The $99 and $299 plans include 1,000 and 3,000 minutes respectively. Custom domain and custom markup need the $299 tier.
Best for chat-first agencies on a budget: Stammer AI. Strong chat agents, with full whitelabel and usage reselling on the $99 plan.
Best if you already build on Vapi or Retell: VoiceAIWrapper. A whitelabel client portal on top of your existing provider keys, with no per-minute markup.
Best if you never want to leave HighLevel: HighLevel's built-in Voice AI. Rebilling needs the $497 Agency Pro plan. Our GoHighLevel guide covers this in detail.

What to look for in a whitelabel voice AI platform

Whitelabel depth. Logo-only whitelabel isn't enough. Clients should log in at your domain, get emails from your address and never see the vendor's name. Check which plan includes the custom domain: it's often not the cheapest one.
Built-in rebilling. You want to charge each client your own per-minute rate through your own Stripe account, with wallets that top up automatically. Without it you're invoicing usage by hand every month.
All-in cost per minute. Some platforms quote a low "hosting" rate and bill the language model, voice and transcription on top. Compare the price with model and voice included, and check whether phone-carrier minutes are extra (they usually are).
Client sub-accounts and concurrency. Count how many client companies each plan allows, and how many calls can run at once. Concurrency matters as soon as you run outbound campaigns.
CRM fit. If your clients live in GoHighLevel, a native marketplace app with workflow actions is far easier than wiring up webhooks.
More than voice. Most clients eventually want SMS and web chat follow-up too. A platform that does both saves you a second tool.

Comparison table

Platform	Whitelabel with custom domain	Built-in client rebilling	GoHighLevel	AI voice cost per minute	Based in
Outbox AI	From $97/mo (Starter)	Stripe, from $149/mo (Growth)	Native marketplace app + workflow actions	14¢ / 12¢ / 10¢ by plan, model and voice included	Perth, Australia
Trillet	$299/mo (Agency); $99 Studio has branding without custom domain	Stripe on both; custom markup on $299	Native (contact sync, workflow triggers)	$0.12 after included minutes; telephony extra	Australia
Stammer AI	$99/mo (Pro White Label)	Resell usage at your own prices	Marketplace app (chat-focused)	$0.11-$0.17 depending on model	USA
Autocalls	$419/mo (White Label, monthly)	Stripe	OAuth via your own GHL app	$0.09 overage on Agency/White Label	Romania
VoiceAIWrapper	From $79/mo (Growth)	Stripe	Webhooks / API / Zapier	Your provider's rates (Vapi, Retell etc.), no markup	UAE
HighLevel Voice AI	Included with GHL ($97+)	Agency Pro ($497/mo) only	It is HighLevel	$0.045 engine + LLM + voice, or $97/mo per sub-account unlimited	USA
Synthflow	Yes (sub-accounts, logos, domains)	Stripe reselling removed 15 Sep 2026	Native marketplace app	Not published; enterprise from $30,000/yr	Germany
Assistable	Yes	Yes	Native workflow actions	Custom proposal, quarterly commitment	USA

Phone-carrier minutes (Twilio, Telnyx and similar) are billed separately on almost every platform unless stated.

The platforms in detail

1. Outbox AI: best all-round whitelabel platform for agencies

Outbox AI is built specifically for agencies that resell AI. Each client gets a sub-account under your brand, with voice agents, chat agents (SMS, WhatsApp, Messenger, Instagram, web), workflows and an AI-built website in the same dashboard.

Whitelabel: logo, custom domain and sender email from the $97 Starter plan. Custom dashboard branding from Growth, API whitelabel on Scale.
Rebilling: connect your own Stripe account, set your own call and chat rates, and client wallets top up automatically (Growth, $149, and above). Outbox takes no revenue share. You can also publish SaaS plans that clients subscribe to themselves.
Voice: sub-800ms responses, barge-in and warm transfers (with a summary, a message or a concierge-style handover). Runs on Twilio, Vonage, Telnyx or SIP, in 100+ languages.
GoHighLevel: a native marketplace app that books into HighLevel calendars and syncs logs to the contact timeline. It adds Send AI Call and Activate AI Chat Agent actions to HighLevel workflows.
Price: $97, $149 or $279 a month, plus 14¢, 12¢ or 10¢ a minute for AI calls with model usage included. 14-day free trial.

Watch out for: Starter caps you at 3 client companies, and automated rebilling starts on Growth.

2. Trillet: best for bundled minutes

Trillet is an Australian whitelabel voice AI platform for agencies.

Plans: Studio ($99/month) includes whitelabel branding, 1,000 minutes and 3 workspaces. Agency ($299/month) adds a custom domain, branded emails, unlimited workspaces, 3,000 minutes and custom minute markup.
Rates: after the included minutes it's $0.12/min, covering the platform, transcription, model and voice. Telephony is billed separately.
Rebilling: Stripe billing on both tiers.

Watch out for: a fully branded portal on your own domain means the $299 tier.

3. Stammer AI: best for chat-first agencies

Stammer started as a whitelabel chat agent platform and added voice.

Whitelabel: the Pro White Label plan ($99/month) gives you your own domain, logo and colours.
Rebilling: you can resell chat replies, voice minutes and agents at your own prices.
Voice rates: priced by model, from $0.11/min (GPT-4.1-nano) to $0.17/min (Claude 3.7 Sonnet).
GoHighLevel: a marketplace app, documented for chat messaging.

Watch out for: if voice is your main product, test its voice latency and call handling against voice-first platforms.

4. Autocalls: best for high-volume outbound

Autocalls is a no-code AI calling platform with a dedicated White Label tier.

White Label tier: $419/month billed monthly, or $355/month billed annually. Includes a custom domain, sub-accounts, Stripe billing and 3,500 minutes.
Overage: $0.09/min, including model, voice and transcription.

Watch out for: the whitelabel tier is the most expensive entry point here. GoHighLevel also needs you to create your own private marketplace app.

5. VoiceAIWrapper: best if you already build on Vapi or Retell

VoiceAIWrapper doesn't run calls itself. It's a whitelabel client portal and billing layer on top of your own Vapi, Retell, ElevenLabs, Bolna or Ultravox account.

Plans: from $79/month (Growth, 5 client accounts, then $15 each), up to $249 and $499.
Rebilling: Stripe rebilling included.
Minutes: billed by your provider at its own rates, with no markup.

Watch out for: you manage two vendors, and each provider's separate model, voice and phone charges. GoHighLevel connects through webhooks rather than a native app.

6. HighLevel Voice AI: best if your agency lives in GoHighLevel

HighLevel's built-in voice agent inherits GHL's own whitelabel (custom domain on every plan). You have two ways to pay:

Pay-per-use: $0.045/min engine fee, plus LLM tokens and $0.015-$0.17/min for voice.
AI Employee: a flat $50 (100 minutes) or $97 (unlimited) per sub-account each month.

Phone system charges apply either way. Rebilling AI usage with markup needs the $497/month Agency Pro plan. See best AI voice agent for GoHighLevel.

7. Synthflow: now enterprise-only

Synthflow was a popular agency choice, but its public pricing is now enterprise-only, starting at $30,000 a year. Its docs say the Stripe integration for reselling to sub-accounts was removed on 15 September 2026. Sub-accounts and branding remain. If you're an agency affected by that change, see Synthflow, Vapi and Retell alternatives.

8. Assistable: managed, proposal-based

Assistable is a multi-channel AI agent platform with deep GoHighLevel roots, whitelabel and rebilling. Its main pricing page now says pricing is agreed in a custom proposal, starting with a quarterly commitment. Example voice rates are $0.07/min base, plus the model and telephony.

What about Vapi and Retell AI?

Vapi and Retell AI are excellent developer platforms, but neither ships a native whitelabel client portal or client rebilling. Agencies on them either add a wrapper (such as VoiceAIWrapper) or build their own dashboard and billing. If you'd rather not, a whitelabel platform is faster to launch. Full comparison.

How to choose

You want one platform for voice, chat and automation, rebilled through your own Stripe: Outbox AI.
You want minutes bundled into a flat monthly fee: Trillet, or Autocalls for higher volume.
Your agency is mostly chatbots: Stammer AI.
You already have Vapi or Retell agents and just need a client portal: VoiceAIWrapper.
Every client already runs on GoHighLevel and you're on Agency Pro: HighLevel Voice AI.

Whichever you shortlist, run the same test script on each one: an inbound booking call, an interruption mid-sentence and a transfer to a human. Time the responses before you commit.

Frequently asked questions

What is a white-label AI voice agent platform?

It's software that lets an agency build AI phone agents and sell them to clients as its own product. Clients log in at the agency's domain, see the agency's branding, and pay the agency's prices, while the platform runs the calls behind the scenes.

How much does a white-label AI voice agent platform cost?

Entry plans with a custom domain range from about $79 to $419 a month. AI calling usually costs $0.09 to $0.17 a minute with the model and voice included, plus phone-carrier charges. Outbox AI starts at $97 a month with calls at 10-14¢ a minute.

Which white-label voice AI platforms include client rebilling?

Outbox AI (from Growth), Trillet, Stammer AI, Autocalls, VoiceAIWrapper and Assistable all include built-in client rebilling. HighLevel includes it only on Agency Pro. Synthflow removed its Stripe reselling integration in September 2026.

Can I white-label Vapi or Retell AI?

Not natively. Neither offers a whitelabel client portal or rebilling. You can add a third-party layer such as VoiceAIWrapper, or use a whitelabel platform like Outbox AI that includes voice, branding and billing in one product.

What markup do agencies charge on AI voice minutes?

It varies by niche and by how much done-for-you setup is included. Outbox reports that most agencies on its platform mark up 3-5x on platform cost.

Sources

Prices and features were checked on each company's official site on 3 October 2026:

Spotted something out of date? Email support@getoutbox.ai and we'll correct it.