API or iCal: what data moves between calendars?

What iCal actually contains

RFC 5545 defines iCalendar as a format for calendar information, including events. Start and end dates and an event identifier are examples of its elements. The standard describes the format; it does not set how often a portal retrieves another calendar.

In accommodation connections, iCal is often used for blocked dates. Airbnb, for example, describes exporting a calendar link and importing a link from another service. Check both services' instructions to understand which blocks transfer and how the receiving system displays them.

A calendar event does not prove that rates, sales conditions or a complete reservation have transferred. If you need these, ask for explicit documentation rather than relying on a synchronisation label.

Why an API connection may cover more data

An API defines the permitted operations and the data a system accepts or returns. Booking.com publishes a Rates & Availability API for inventory, rates and restrictions, and a separate Reservations API for bookings and changes.

ARI stands for availability, rates and inventory. It describes an area of data exchange; it does not confirm that a particular product supports every rate plan, rule or channel.

Check sending and receiving separately for each data type with the supplier. Access to one interface does not automatically mean access to other functions. A portal's public documentation does not confirm the capabilities of your contracted package.

Differences that affect daily work

Assess delays against the way you sell

Airbnb's instructions describe periodic refreshes of imported calendars and manual refreshes subject to limits. Other services do not necessarily use the same interval. Read the current rules in the linked source before setup.

For your own decision, record how long you can accept a mismatch between two views. If the same last available unit can be booked immediately on several portals, check the whole reconciliation process and how discrepancies are handled.

The speed of a specific integration needs measuring in an agreed test. We do not give a universal speed or guarantee that iCal or an API prevents every double booking.

When iCal may be a simple enough solution

Consider iCal if you mainly need to transfer blocked dates, accept both services' refresh rules and are prepared to manage other data separately. This is a criterion for your own assessment, not a recommendation of a brand.

Illustrative example: an owner wants a personal occupancy overview while managing rates on the sales portal. A calendar import may meet that limited need if it transfers the required dates. Check modifications and cancellations before relying on it.

If you need central rate changes, pooled inventory across rooms or specific restrictions, do not assume a calendar will meet the requirement. Ask to see the functions you need and compare them with the API offering.

A short checklist before relying on a connection

This is a proposed supplier demonstration, not a report of completed testing. Use an agreed test property or a safe procedure that does not create real bookings.

1. Record system A, system B, the unit and the data you want to transfer.
2. Agree the starting state and expected result for a new blocked period.
3. Check date changes and cancellation, including reopening dates.
4. For an API offering, demonstrate rates and required restrictions separately.
5. Record the time, status and where to report a mismatch.
6. Decide who monitors errors and how to disconnect without losing sight of reservations.

Match the technical requirement to the quote

Confirm what the connection does first, then request a price for that scope. The cost calculator in the related topics adds up your figures; it does not assume either technology is free or more expensive.

For broader context on inventory, PMS and reservations, open the introductory guide. Source policies and supplier relationships are explained in Methodology and About.