The calendar is the whole job

Almost everything that goes wrong in a short-let is fixable. The boiler dies and you call someone. The cleaner is ill and you go yourself. A guest breaks a glass and you buy a glass.

Selling the same week twice is different. There is no version of that afternoon where everybody is happy. Someone has booked flights around a house they cannot have, and you are the person telling them.

Why it happens

It happens because availability lives in more than one place at once. A listing on one platform, a listing on another, a direct site, a spreadsheet, and your own head. Every additional place is another chance for the truth to diverge.

The standard answer is iCal. Each platform publishes a calendar file; every other system reads it periodically and blocks what it finds. It works, it is free, and it is what almost every tool in this category is doing underneath.

What iCal cannot do

It is worth being blunt about the limit, because the marketing around this usually is not.

iCal is a file that gets fetched on a schedule. It is not a live connection. Between one fetch and the next there is a window — usually minutes — where a date is sold on one platform and still open on another. Two guests booking the same night inside that same window is unlikely. It is not impossible, and no iCal-based system anywhere avoids it, including ours.

Anyone promising a system that makes double bookings impossible is either using a real two-way API integration with that specific platform, or is being loose with the truth.

What actually reduces the risk

Connect every platform you are still listed on, not just the busy one. The calendar you forgot is the one that will eventually sell a week you have already sold.

Block your own stays by hand — your family visiting is a booking, and it should behave like one.

Check the sync status occasionally. iCal URLs expire quietly, and a calendar that stopped updating three weeks ago looks exactly like a calendar with no bookings.

And keep fewer channels than you think you need. Every platform you add is a small permanent tax on your attention.