How Treatwell automated 75% of call handling with AI & Twilio

Discover how Treatwell automated 75% of call handling with AI and Twilio, delivering 50% faster bookings and a 10% increase in appointments.

About Treatwell

Treatwell is Europe’s leading platform for beauty and wellness appointments, connecting millions of customers to salons and spas across the continent. But behind their sleek digital interface, there was a challenge brewing: their inbound call system was overworked, heavily manual, and only available during business hours.

With rising call volumes and growing expectations for on-demand service, Treatwell set out to create a booking experience as modern and effortless as their app, one that could handle calls quickly, reliably, and around the clock.

Streamlining Calls Without Losing the Personal Touch

57% of customer service leaders expect call volumes to rise in the next 1–2 years, even with more digital options. At the same time, brand loyalty could fall by 25% if businesses don’t deliver fast, seamless, on-demand experiences.

Treatwell’s salon partners were overwhelmed by phone calls. Appointment requests tied up front desks, led to long wait times, and left customers without answers after hours. With innovation at the core of its business, Treatwell saw an opportunity to expand its offering. By introducing Voice AI, they could give salons a fully automated phone channel available 24/7, natural-sounding, and still able to escalate to an agent when needed.

“Our goal was to reduce pressure on staff without compromising experience, we wanted a solution that could have a real conversation, not just read a script.”

The Zennify Solution

Channels enabled

24/7 AI voice assistant, seamless agent handoff, multilingual roadmap

Systems integrated

Twilio Voice and Studio Flow, ConversationRelay STT/TTS, Treatwell APIs

Processes automated

Intent capture, booking and confirmation, contact collection

Third-party applications

Twilio Voice, ConversationRelay, Zennify AI Assistant Kickstarter

AI-Powered Voice Booking, Built on Twilio

To bring this to life, Treatwell partnered with Zennify (formerly Terazo) to design and implement an intelligent voice assistant using Twilio Voice, Twilio’s new ConversationRelay, and Zennify’s AI Assistant Kickstarter framework.

Here’s how it works:

When a customer calls, Twilio routes the interaction through Studio Flow and launches a GenAI-powered voice assistant, built by Zennify. The assistant:

Understands caller intent through natural language conversations
Pulls real-time data from Treatwell’s APIs, including service menus, prices, and availability
Guides the caller to select a treatment and choose an appointment
Collects contact details and confirms the booking, automatically
Escalates to a live agent at any point if the customer needs help or reassurance

ConversationRelay enhances the experience with fast, reliable speech-to-text (STT) and text-to-speech (TTS) capabilities.

Each step is powered by a modular AI architecture designed for clarity, speed, and precision. It’s automation with empathy, designed to sound natural and feel seamless.

“We built the assistant to be fast, flexible, and feel like a real conversation. It’s not just automation, it’s a better experience for customers and staff.”

— Tobi Schoder, Lead Product Manager, Zennify

Results that speak for themselves

75%

of calls are now handled entirely by AI

50%

faster appointment booking

10%

increase in total bookings

What changed for Treatwell

The impact was immediate and measurable. With the AI voice assistant fully live, Treatwell saw meaningful improvements across customer experience, staff efficiency, and business growth:

75% of calls are now handled entirely by AI: Most callers now complete their booking from start to finish without needing an agent. The AI assistant understands their needs and gets them scheduled, quickly and naturally.
‍
50% faster appointment booking: Conversations are shorter and more focused, cutting booking time in half. That means staff spend less time on the phone, and more time delivering great in-salon service.
‍
10% increase in total bookings: With 24/7 availability, Treatwell now captures more appointments than ever, especially during evenings and weekends.

“It’s been a game-changer for our team and our customers. People can book anytime, the experience feels natural, and our staff finally have time to focus on what matters most, taking care of clients.”

What’s next: Smarter conversations, broader reach

With their AI assistant now live and driving results, Treatwell is looking ahead. Plans are already underway to expand into new channels, add multilingual capabilities, and tailor conversations based on customer history.

This success story is just the beginning. Together with Zennify and powered by Twilio, Treatwell is proving that even the most personal of experiences can be made better, faster, and more human through smart technology.