Double bookings are every holiday host's nightmare. iCal sync is the standard solution — but it only works if you understand how it behaves and where it falls short.
Double bookings are one of the most damaging things that can happen to a holiday rental host. You have two guests expecting to arrive on the same dates, one of whom you have to cancel at the last minute. The OTA may penalise you with a reduced ranking or automatic bad review. The cancelled guest is angry, and rightly so. Your credibility with both platforms takes a hit.
The good news is that double bookings are almost entirely preventable. The mechanism is iCal sync, and this guide explains exactly how it works, how to use it correctly, and what to do when iCal alone is not enough.
iCal is short for iCalendar, an open file format for sharing calendar data over the internet. It was standardised in 1998 and is now universally supported by calendar applications — Google Calendar, Apple Calendar, Outlook, and nearly every holiday rental platform.
An iCal feed is a web address (URL) that, when accessed, returns your calendar data in a structured text format. The data includes which dates are blocked or booked. Any system that can read an iCal URL can import those blocked dates into its own calendar.
For holiday hosts, this is the mechanism that allows Airbnb, Booking.com, Vrbo, and your direct booking site to communicate with each other about availability — even though they are completely separate systems with no direct integration.
Here is the flow:
In the reverse direction, if a booking comes in on Booking.com first, your Airbnb account should have Booking.com's iCal feed imported — so Airbnb will see those dates are blocked and prevent a second booking.
The essential point: iCal sync is only effective if it is set up in both directions, between every platform you use.
Every major OTA generates an iCal export URL for each listing. Here is how to find them:
Go to: Calendar > Availability Settings > Sync Calendars > Export Calendar
Copy the link that starts with https://www.airbnb.co.uk/calendar/ical/...
Go to: Property > Calendar > iCal Export Copy the iCal URL from the export dialog.
Go to: Listing > Calendars > Import/Export > Export your calendar
Copy the .ics URL.
Most property management platforms (including LetPilot) generate an iCal URL for each property. Find it in your property settings or calendar section.
If you list on three platforms — let us call them A, B, and C — you need the following imports to achieve full two-way sync:
| Platform | Import From |
|---|---|
| A | B's iCal URL, C's iCal URL |
| B | A's iCal URL, C's iCal URL |
| C | A's iCal URL, B's iCal URL |
That is six separate imports for three platforms. For four platforms, it is twelve. The number grows quickly, which is why a central management platform that handles all sync relationships from one place is significantly easier to maintain.
Here is the critical limitation that catches many hosts off guard: iCal sync is not instant.
When a booking is confirmed on Platform A, the blocked dates do not immediately appear on Platform B. Platform B needs to "poll" (fetch) Platform A's iCal URL, and it does this on its own schedule — which you cannot control.
Typical polling frequencies in 2025:
This means that for up to six hours after a booking on Airbnb, Vrbo might still show those dates as available. If your property is popular and you receive frequent enquiries, another guest could book the same dates on Vrbo before the block propagates.
For most hosts, this is a low-probability risk. But it is not zero. During peak summer season in a popular UK destination, receiving enquiries every few hours is normal.
Most OTAs allow you to set a preparation or buffer time between bookings. Even a 24-hour buffer means that a booking on Airbnb blocks the day before and after in addition to the booked dates. This gives the sync time to propagate and prevents a back-to-back booking on another platform during the window before sync completes.
Longer minimum stays reduce the number of bookings you receive, which in turn reduces the frequency of sync events. A property with a 3-night minimum has fewer booking changes per month than one that accepts 1-night bookings, and fewer opportunities for sync lag to cause a problem.
Property management platforms that have direct API connections to Airbnb and Booking.com do not rely on iCal polling. Instead, they receive and send booking data in real time via API calls. When a booking arrives on Airbnb, the management platform's server is notified immediately and pushes a block to all other channels within seconds.
This is the most reliable way to prevent double bookings across channels. It is available on most paid property management platforms, including LetPilot.
Understanding what data is in an iCal feed helps you avoid common mistakes. A standard iCal export from an OTA typically contains:
Important: some platforms only export confirmed bookings in their iCal feed, not pending enquiries or hold requests. If you put a date on hold to consider an enquiry, that hold may not appear in your iCal feed — meaning other platforms will still show it as available.
Never assume iCal sync is working. Test it:
Repeat this test after any listing update on any platform, as some updates can regenerate the iCal URL.
iCal sync is a good solution for independent hosts with moderate booking volumes. It becomes inadequate when:
In these situations, a property management platform with real-time API connections is the right investment.
To put the risk in perspective:
One double booking can easily cost £200–£500 in direct costs and an unknown amount in lost future bookings due to ranking and review damage. Against this, the cost of a paid management platform with robust sync is trivial.
LetPilot manages iCal sync across all your platforms automatically, with built-in conflict detection and real-time calendar updates — so double bookings become a thing of the past. Try LetPilot free at letpilot.co — no credit card required.