title: "iCal Sync: Preventing Double Bookings" description: "How to keep availability in sync across Airbnb, Booking.com, Vrbo, and your direct booking site without a channel manager." date: "2026-02-02" author: "Alveriano" category: "operations" tags: ["iCal", "operations", "availability", "channel management"] featured: false draft: false
A double booking is the most operationally damaging mistake a property can make. You either relocate a guest (expensive and reputation-damaging) or cancel a booking (refund plus potential review penalty). Both outcomes are worse than the vacancy you were trying to avoid.
iCal sync is the simplest way to keep availability consistent across platforms without investing in a full channel manager.
How iCal sync works
iCal is a calendar format (.ics) that every major booking platform supports. Each platform publishes a feed URL containing your blocked dates. Other platforms read that feed and block the same dates automatically.
The chain:
- Guest books on Airbnb → Airbnb blocks those dates in its calendar
- Booking.com reads Airbnb's iCal feed → blocks the same dates
- Your direct booking site reads both feeds → blocks the same dates
- Reverse sync: each platform's feed is imported into the others
The result: when a booking is made on any platform, all other platforms update within the sync interval.
Setting up iCal sync: platform by platform
Airbnb
- Go to your listing → Availability → Pricing and availability
- Scroll to "Connect calendars"
- Copy your Airbnb iCal export URL
- Import iCal URLs from Booking.com, Vrbo, and your direct site
Booking.com
- Go to Property → Calendar → Sync
- Copy the export link
- Add import links from other platforms
- Set sync frequency (Booking.com defaults to every 4 hours)
Vrbo
- Go to Calendar → Import/Export
- Export your Vrbo calendar URL
- Import URLs from other platforms
Your direct booking site
Most booking engines support iCal import. Add the export URLs from each OTA platform. Ensure your site also publishes its own iCal feed that the OTAs can import.
The sync delay problem
iCal sync is not real-time. Most platforms pull external calendars every 2–6 hours. This creates a window where a double booking can occur.
Risk scenario: Guest A books on Airbnb at 10:00 AM. Booking.com won't see this update until its next sync cycle, potentially 14:00–16:00. If Guest B books the same dates on Booking.com at 11:00, you have a double booking.
Mitigating sync delays
Option 1: Buffer days. Block the day before and after each booking as unavailable. This reduces maximum occupancy but eliminates most overlap risk.
Option 2: Manual calendar checks. After every booking on any platform, manually update the others immediately. This is reliable but doesn't scale.
Option 3: Instant sync tools. Services like iCalSync or Hospitable offer near-real-time sync by polling feeds every 15–30 minutes. This is the practical middle ground.
Option 4: Channel manager. Tools like Lodgify, Hostaway, or Guesty provide API-level integration with each platform. Availability updates are near-instant. This is the right solution once you're managing more than 2–3 properties.
Common iCal sync problems
1. One-way sync
Importing a feed only blocks dates. It doesn't push your bookings back to the source. You need bidirectional sync — each platform imports every other platform's feed.
For 3 platforms, that's 6 connections:
- Airbnb → imports Booking.com + Vrbo + Direct
- Booking.com → imports Airbnb + Vrbo + Direct
- Vrbo → imports Airbnb + Booking.com + Direct
2. Stale feeds
If a platform's export URL changes (it shouldn't, but it happens after account updates), the sync breaks silently. Check your feeds monthly.
3. Timezone mismatches
Ensure all platforms are set to the same timezone as your property location. A booking blocked for "15 February" in UTC might appear as "14 February" or "16 February" in a different timezone, creating gaps or unnecessary blocks.
4. Cancelled bookings not clearing
When a booking is cancelled, the calendar should unblock those dates. Most platforms handle this correctly, but verify after each cancellation. Stale blocks mean lost availability.
When to upgrade to a channel manager
iCal sync works well for:
- Single properties listed on 2–3 platforms
- Properties with moderate booking frequency (fewer than 20 bookings per month)
- Owners who check calendars regularly
Consider a channel manager when:
- You manage 3+ properties
- Booking frequency is high enough that sync delays create real risk
- You need rate sync (iCal only syncs availability, not pricing)
- You want automated messaging across platforms
Checklist for reliable iCal sync
- [ ] Export URLs set up on every platform
- [ ] Import URLs added to every other platform (bidirectional)
- [ ] Sync frequency set to maximum on each platform
- [ ] Timezone consistent across all platforms
- [ ] Monthly feed health check scheduled
- [ ] Process for manual updates after each booking
- [ ] Cancellation verification process in place
iCal sync is the minimum viable solution for multi-platform availability management. It's not perfect, but it prevents the majority of double bookings without requiring paid tools or complex setup.