iCal Sync Explained: How to Stop Double Bookings Across Airbnb, Booking.com & Your Own Site
What iCal sync is, why it's the single most important feature for shortlet hosts listing on multiple channels, and how to set it up so a booking on Airbnb blocks your own calendar instantly.
By StayOS Team · Channels · 2026-02-18
The most expensive bug in short-term rentals isn't in any code — it's two guests with keys to the same apartment on the same night. Double bookings happen the moment you list the same unit on two channels and keep two calendars. iCal sync exists to make that impossible.
What iCal actually is
iCal (Internet Calendar) is the standard calendar format used by Airbnb, Booking.com, Vrbo and Google Calendar. Every platform can publish its booked dates as an iCal feed — a URL — and import feeds from other platforms. Sync is just connecting those feeds in both directions.
Why it matters more than ever
- You list on Airbnb for reach, Booking.com for corporate guests, and now your own discovery page for commission-free direct bookings
- A booking on any one channel must block the dates on every other channel — instantly
- Without sync, you're the human API between three calendars, and you will slip up eventually
How a booking flows through sync
Guest books Monday–Wednesday on Airbnb. Airbnb publishes those dates to its iCal feed. Your management platform imports that feed, blocks Monday–Wednesday on the unit's availability calendar, and exports the block back out — so Booking.com and your discovery page also show the unit unavailable. Nobody updates anything by hand.
What to look for in iCal support
- Both directions: import external calendars and export yours
- Per-unit feeds, not just per-house — a 4-unit building needs four calendars
- Conflict detection — if a direct booking collides with an imported block, you're warned, not silently double-booked
- Manual blocking support — maintenance and owner-use blocks should propagate outward too