Booking automation is supposed to simplify life—especially when you’re running paid events and every slot on your calendar equals money. So, imagine the revenue shock when your once-reliable Calendly account starts double-booking paid calls immediately after transitioning from a free trial to a paid plan. That’s exactly what happened to me. What initially looked like a technical blip turned out to be a configuration issue with syncing availability across event types and calendars. After sifting through forums, support tickets, and my own logs, I implemented a slot-sync fix that not only resolved the glitch but saved potentially thousands in lost revenue.
TL;DR
After upgrading from a Calendly trial to a paid plan, I encountered a bug where paid event types began to double-book clients. The issue stemmed from overlapping availability not being properly synced across different event types. The solution was to implement a “slot-sync” fix by restructuring availability and calendar integrations. Once applied, the fix prevented overlapping bookings, safeguarded my revenue stream, and restored trust in the booking process.
What Went Wrong After the Trial Ended?
During Calendly’s generous trial period, all premium features are activated. I took full advantage—creating multiple event types, integrating two calendars (personal and business), and offering both free and paid consultations. Everything worked smoothly, lulling me into a sense of security. But once my trial ended and I subscribed to the Essentials plan, things changed—quietly but drastically.
I began noticing that people were able to book during the same time slot across different event types. One day, I had three overlapping 30-minute paid consultations at 2:00 PM. Not only was this logistically impossible, it embarrassed me professionally and damaged my clients’ experience.
The Root of the Problem: Calendly’s Availability Logic and Event Hierarchy
The crux of the issue lies in how Calendly handles availability management across event types, especially when you upgrade from a free trial to a paid plan with more limited features.
- During the trial, Calendly allows synced calendars to apply availability globally across all event types.
- After upgrading, certain granular availability settings become restricted based on your subscription tier.
- Conflict detection between event types and calendars becomes less predictable unless explicitly configured.
Calendly calculates open slots per event type, rather than viewing all your events holistically. If two different event types (say, a free intro call and a paid deep-dive session) happen to allow bookings at the same time, and there’s no configured conflict logic, Calendly treats those times as available independently—hence the double bookings.
This behavior seemed counterintuitive since I expected Calendly to block out booked time slots across all event types once a commitment was scheduled.
Client Trust and Lost Revenue
The financial implications became unbearable quickly. Each missed or overbooked paid appointment meant a refund, an apology, and sometimes a lost client. But even worse was the trust erosion. Clients booking high-ticket sessions expect reliability—not confusion.
One client who experienced the double-booking fiasco wrote, “It didn’t feel professional. I thought I had the slot confirmed, and then someone else was on the call. I won’t be back.” That sentence hit like a brick.
The Invisible Conflict: How Test Event Types Wreak Havoc
Another discovery I made was that inactive or hidden test event types from the trial were still influencing slot availability. Even though they were unpublished, Calendly continued to reserve time slots “just in case” anyone had a link. This meant actual paid events were being denied access to my real availability because ghost events were blocking them.
This was compounded by the fact that calendar sync settings didn’t always carry over after the trial. My business calendar was connected, but was not actively limiting availability post-upgrade the way it had previously during the trial. The sync needed to be manually refreshed.
The Slot-Sync Fix
Implementing the slot-sync fix required a multi-step strategy to recalibrate availability. Here’s how I did it:
- Audit All Event Types: I reviewed every active and inactive event type, deleting old test links and archives that could access the calendar.
- Standardize Duration & Buffers: I reformatted all paid sessions into 30-minute or 60-minute blocks with clear buffer times around each to prevent overlap.
- Manually Sync Calendars: I disconnected and reconnected both my business and personal calendars through Calendly’s integrations. This helped reset any default behavior carried over from the trial.
- Use the Work Hours Template: Rather than inputting availability individually per event type, I created a standardized availability template across all events via the “Work Hours” setting.
- Enable Conflict Detection for All Calendars: I made sure Calendly was set to check all integrated calendars before opening up time slots per event. This required toggling hidden settings under Calendar Connections.
Once complete, I ran simulations by attempting to book overlapping sessions. The system now accurately prevented overlap, and all future appointments reflected real, watertight availability.
Calendly Support: Helpful but Limited
While I have to credit Calendly’s support team for trying to assist, their responses were largely procedural. They pointed me to FAQ articles and encouraged upgrading to higher-tier plans for additional features like round-robin availability, but the immediate issue had to be solved with careful backend changes.
The experience revealed a need for better documentation around trial-to-paid transitions. Most users won’t know their system behavior has changed—and unfortunately, they’ll only notice once something breaks.
Takeaways and Best Practices
This experience served as a wake-up call about the fragility of automation tools when misconfigured. Here are my top lessons for anyone running paid events on Calendly or a similar tool:
- Always triple-check your availability after upgrading or changing settings. Don’t assume older events work the same way.
- Keep your calendar integrations clean. Remove unused accounts or test profiles that can introduce conflicting slots.
- Test your booking links as if you were a client. Simulate overlaps, cancellations, and changes.
- Use buffers and standardized durations to maintain consistent time slots and eliminate ambiguity.
Calendly Is Still Worth It—But Only with Precision
Despite my frustrations, I’m still using Calendly. Scheduling is a nightmare without automation, especially when money hinges on every call. But the experience taught me that automation without oversight is wishful thinking.
With the slot-sync fix in place and better calendar hygiene practices, bookings are accurate, clients are happy, and my revenue is protected. Calendly is powerful, but it’s only as good as the setup behind it.
Make sure yours is airtight—your wallet will thank you.
