What ARI means
Every hotel booking depends on three answers: can this room be sold on this date, at what price, and how many are left. ARI is the shorthand for that data. It is the feed a channel manager pushes out and the content a bedbank, OTA or booking engine reads when it builds a hotel offer.
The three parts change at different speeds. Rates are set per room type and rate plan, often by date range and by number of guests. Availability covers open or closed status and restrictions such as minimum stay or closed to arrival. Inventory is the count of rooms that can still be sold, which falls with every booking and rises with every cancellation.
Many ARI interfaces follow OpenTravel Alliance message types. Google's hotel ARI specification, for example, uses separate messages for rate amounts, availability and restrictions, and inventory counts. Each update is keyed to a combination of property, room type and rate plan, so the mapping of those codes between systems has to be exact.
ARI is distinct from static content such as descriptions, photos and amenities, which changes rarely and is handled through content mapping. It also underpins commercial rules: rate parity concerns the R, and an allotment is a slice of the I reserved for one buyer.
How ARI works
ARI flows outward from the hotel's systems, while bookings flow back and change the inventory.
- Hotel sets the source dataRevenue or reservations staff set rates, restrictions and room counts in the PMS, central reservation system or channel manager.
- Updates are packagedThe system builds messages for each property, room type and rate plan, covering a date range, such as a rate change for the next 30 nights.
- Channels receive and store ARIOTAs, bedbanks and metasearch partners load the update into their own cache, which drives search results and prices shown to buyers.
- A booking reduces inventoryWhen a room sells on one channel, the booking flows back to the hotel and the inventory count drops.
- New counts are pushed everywhereThe channel manager sends the reduced inventory to every other channel. Delays at this step are a common cause of overbookings.
ARI in practice
Illustrative ARI update for a city hotel in Dubai for 12 to 15 December:
- Availability: Deluxe King, Flexible rate plan, open; minimum stay two nights; closed to arrival on 14 December.
- Rate: AED 650 for one adult, AED 720 for two adults, breakfast included.
- Inventory: 8 Deluxe King rooms left to sell on 12 December and 3 on 13 December.
In Google's ARI interface the rate goes in an OTA_HotelRateAmountNotifRQ message, restrictions in OTA_HotelAvailNotifRQ and room counts in OTA_HotelInvCountNotifRQ. Google requires transaction, rate, inventory and availability messages before it shows a price.
Who uses it
Advantages and limitations
Advantages
- A single source of ARI lets a hotel sell on many channels without editing each extranet by hand.
- Date-level restrictions give revenue managers precise control, such as minimum stays over peak nights.
- Inventory updates after every booking reduce the risk of selling the same last room twice.
- Standard message types, often based on OpenTravel, make new channel connections quicker.
Limitations
- Any lag in pushing inventory changes can cause overbookings on high-demand dates.
- Room type and rate plan codes must be mapped exactly; a mapping error sends the wrong price to a channel.
- Channels that cache ARI may show prices that are already out of date, raising look-to-book costs.
- Each channel supports a different subset of restrictions, so complex rules may not display everywhere.
Frequently asked questions about ARI
What is the difference between availability and inventory in hotels?
Inventory is the number of rooms of a type that can still be sold on a date. Availability is whether a room type and rate plan is open for sale on that date and under what conditions, such as a minimum stay. A hotel can have inventory left but make a rate unavailable by closing it.
What are common ARI restrictions?
Typical restrictions include minimum and maximum length of stay, closed to arrival, closed to departure, and a full stop sell for a date. They are set per room type and rate plan, and let a hotel shape demand, for example by blocking one-night stays on a peak Saturday while leaving longer stays open.
Why does a hotel show different availability on different websites?
Usually because channels received updates at different times, because the hotel closed a rate on some channels on purpose, or because a reseller is selling from its own allotment. Cached search results also lag behind live inventory, so the room may disappear when the user tries to book.
What is an ARI push versus an ARI pull connection?
In a push connection the hotel or channel manager sends ARI changes to the channel as they happen. In a pull connection the channel requests prices and availability from the supplier's system when it needs them, often at search time. Many hotel APIs combine both, pushing static rates and checking live availability at booking.
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