Syncing Airbnb and Booking.com calendars so a room never sells twice

HostBooking · Updated Nov 2, 2026 · 7 min read

Airbnb and Booking.com both support iCal, so you can link their calendars both ways without paid software. Airbnb re-reads outside calendars every 3 hours and Booking.com every 2 hours: that gap is where double bookings come from. Booking.com only allows sync when each room type has exactly one unit. Here is how to link, check and recover.

What each side supports

This is the easiest pair among the OTAs Vietnamese homestays use: both publish official instructions, and both can export and import a calendar link. The differences are refresh timing and Booking.com’s eligibility rule.

Both figures come from Airbnb and Booking.com themselves. A night just sold on Booking.com can stay open on Airbnb for up to 3 hours, and the other way round for up to 2. For stays booked weeks ahead that rarely matters. For a booking made for tonight, it is a real risk.

Booking.com’s one-unit-per-room-type rule

Booking.com only enables calendar sync when the property has 20 room types or fewer and each room type has a single unit. Its own example: "Sea-view studio A", "Sea-view studio B" and "Loft C" are three types of one unit each, which is fine; a "Standard double room" with five identical units is not.

If your homestay sells four identical rooms under one Booking.com room type, you can either split them into four one-unit types and link each, or use a channel manager connected to Booking.com directly. Airbnb works per listing, one room per listing, so it does not have this limit.

Direct link or a central calendar

Direct: the Airbnb link goes into Booking.com and the Booking.com link into Airbnb. Enough if these are your only two channels and you take no phone or repeat bookings.

Central calendar: each OTA imports one link from your software, and the software imports each OTA. It adds a few minutes (HostBooking reads OTA calendars every 5 minutes), but you gain three things: website and walk-in bookings block both OTAs too, you see everything in one place, and the software warns you when a night is double-booked. Do not use both methods for the same room: the calendars end up blocking each other and cancelled nights are hard to release.

Setting it up

1. On Booking.com, open Rates & Availability → Sync calendars and check your room is eligible (one unit per type).
2. Click Add calendar connection on the right room, choose Skip to export, name it ("Airbnb"), click Copy link.
3. On Airbnb, open Calendar, pick the listing, go to Availability → Connect calendars → Connect to another website. Paste the Booking.com link, name it, click Add calendar.
4. On the same screen, copy the listing’s Airbnb calendar link.
5. Back on Booking.com, under Sync calendars click Complete setup (or Add calendar connection), paste the Airbnb link, name it, click Next step, then Done.
6. Wait for the Booking.com status to read Okay. Import only or Export only means one direction is missing.
7. Click Import now on Booking.com and Refresh Calendar on Airbnb, then compare one real stay on both sides.

With a central calendar, steps 3 and 5 use your software’s link instead of the other OTA’s. On HostBooking each OTA gets its own link that leaves out that OTA’s own guests, so the calendars cannot lock each other.

What iCal does not carry

• Prices: a price change on Airbnb does not reach Booking.com.
• Guest details: name, phone and party size do not travel over iCal.
• Booking rules: minimum stay or preparation time set on Airbnb may not carry over. Airbnb also says nights blocked on another site may not block on Airbnb.
• Several units under one type: Booking.com will not sync them, as above.

Checklist against double bookings

• Booking.com shows Okay; Airbnb shows a recent last-updated time for the import.
• Each room is linked on its own; never one link for several rooms.
• For a booking for today or tomorrow, close that night by hand on the other OTA right after accepting.
• If you regenerate a link on one side, paste it again on the other at once.
• Once a week, compare both calendars for the next 14 days.

If a double booking still happens

Booking.com side: move the guest to a room of the same or better standard if you have one. If not, you must find comparable or better accommodation elsewhere and cover the cost, ideally including transport. Contact Booking.com to mark the reservation as a double booking. Booking.com waives commission on it only if the property has been live under 30 days, or has had no more than four double bookings in 12 months.

Airbnb side: a host who cancels a confirmed booking pays 10% of the reservation amount if more than 30 days out, 25% at 2–30 days, 50% within 2 days, with a USD 50 minimum. Those dates are blocked for other guests, and Superhost status can be lost.

Because Airbnb charges a percentage while Booking.com asks you to rehouse the guest, many owners keep the Airbnb guest and relocate the Booking.com one. Price both before deciding.

On HostBooking

OTA calendar sync reads Airbnb and Booking.com every 5 minutes, gives each OTA its own link, and alerts you when a night is double-booked. If you forward the booking emails from Airbnb and Booking.com, bookings arrive with the guest name and price, often before the next iCal read. HostBooking takes no commission on bookings; plans are on the pricing page. The basics of iCal and its common failures are in the iCal sync guide.