iCal or API for booking synchronisation: differences and limits
Compare iCal and API booking connections: data, refresh times and checks to prevent duplicates before check-in.
In this guide
Synchronising a calendar and preparing guest registration are related but different tasks. Before choosing a connection, decide whether you need to block dates, import bookings or obtain check-in information. The label iCal or API alone does not explain what information your property will receive.
Data
Scope of each connection
Updates
The provider's update frequency
Verification
Changes and duplicates
What changes between iCal and an API
iCal uses a calendar published by one system and retrieved by another. An API can exchange the information that each provider has implemented and authorised. An API does not guarantee a two-way connection or access to every booking field. Always check the scope of the specific integration.
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Availability: confirm whether the connection transfers bookings, blocked dates or both.
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Data: check which fields arrive and which the guest must complete.
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Changes: verify how new dates, amendments and cancellations appear.
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Direction: distinguish importing from a platform from exporting to it.
Is synchronisation immediate?
Do not assume that a calendar updates instantly. Each system decides when to retrieve the source. Check the frequency and behaviour of each connection separately rather than applying one providerās stated interval to every service.
Airbnb publishes its own import and refresh conditions. Its interval does not describe how often iButlers or another platform retrieves a calendar. Read the linked documentation before arranging an arrival that depends on a recent change.
A check before relying on the connection
Identify the properties
Identify the source and destination properties. Do not rely only on similar names.
Review a booking
Check an authorised test booking or an existing booking you can manage, without adding fictional personal details to official submissions.
Compare the information
Compare dates, reference and status. Also check the time zone used by each tool.
Verify the changes
Verify how changes and cancellations are handled before enabling automation for that property.
Document what is missing
Document which information is missing and how you will request it from the guest. An imported booking is not a completed registration.
What to check if a booking appears twice
Check whether the same property receives bookings through two paths, such as a calendar and a PMS integration. Find both references and their sources before deleting anything. Ask for help if you cannot determine which record retains the changes and associated submissions.
Review before disconnecting
Do not disconnect an integration as your first step without checking upcoming arrivals. Record when the problem occurred and a description without guest data so support can narrow it down.
Prepare the next step in iButlers
If you need the source link, read the existing tutorials. Then review the online check-in service to distinguish an imported booking from collecting guest details.
Online check-in and guest registration with iButlers
Sources and review
Editorial review: 18 October 2026. Menu labels and connection capabilities can change; the relevant providerās help is the reference for configuration.
