What Is ARI in Hotels?
Availability, Rates and Inventory — the data every PMS and channel manager pushes to OTAs, and the full vocabulary of restrictions (stop sell, CTA, CTD, MinLOS, MaxLOS) that travels with it.
ARI Definition
ARI stands for availability, rates and inventory — the three pieces of data a property management system or channel manager pushes out to every OTA so guests see accurate rooms, prices and booking rules everywhere at once.
Every OTA search a traveller runs is answered from ARI data. If a hotel's ARI is wrong or late, the symptoms show up as overbookings, mismatched prices, or rooms that look sellable online when they aren't. Getting ARI right is less about any one setting and more about the full vocabulary below — because availability, a rate, and a restriction can each independently be correct while the combination still sells a room that shouldn't be sold.
The ARI Vocabulary: A Spec Table
Terminology for the restriction types follows Google's Hotel Prices ARI documentation (master/stop-sell, arrival/departure, length-of-stay and stay-through, booking offset)[1] and channel-manager vendor documentation on CTA/CTD behaviour.[2]
What Is a Stop Sell in a Hotel?
A stop sell closes a room type or rate plan for a specific date, making it unbookable everywhere it's pushed — regardless of how many rooms are actually still in inventory.
It's the blunt instrument of ARI: unlike availability, which is a running count, a stop sell is a flag that overrides the count entirely. A property with 8 rooms technically free can still show zero availability if a stop sell is active — useful for holding rooms back for maintenance, an owner block, a group that hasn't confirmed, or simply pausing OTA sales while the front desk sorts out a walk-in. Because a stop sell overrides the count rather than changing it, forgetting to lift one is one of the most common causes of a hotel looking "sold out" on an OTA while rooms sit empty.
What Is a Rate Plan?
A rate plan is a named pricing and policy package tied to a room type — covering the price, the cancellation terms, what's included, and who is allowed to book it.
The same physical room can be sold under several rate plans at once, each with its own price and its own restrictions. A Deluxe King might carry a cheaper Non-Refundable Saver plan with a 3-night MinLOS during a busy weekend, and a pricier Flexible Rate plan with no stay restriction at all, sold side by side on the same OTA. Rate plans are also where breakfast inclusion, parking, or a corporate-only rate typically live, which is why "what's my rate plan structure" is usually the first question a channel manager setup needs answered before any restriction can be applied sensibly.
What Are CTA and CTD?
Closed to Arrival (CTA) stops new stays from starting on a date; Closed to Departure (CTD) stops a stay from ending on one. They solve opposite problems.
CTA is used to smooth a flood of check-ins around a date you already know will be busy at the front desk — a guest who is already staying through that date can still leave normally, but nobody new can check in that day. CTD does the reverse: it prevents a stay from ending on a date you don't want empty rooms appearing, usually a sold-out night or the final night of an event, by requiring anyone already in house to stay at least one more night. A channel-manager vendor's own documentation describes the same mechanic for short-term rentals — CTA and CTD toggles that sync across every connected channel the moment either is set.[2]
How Is ARI Sent to OTAs?
Push, pull, and why the gap between them is where overbookings live.
Most modern connections are a push: the property management system or channel manager sends availability, rates and restrictions out to each OTA the instant something changes, rather than waiting for the OTA to ask. The reverse direction is effectively a pull from the hotel's side — new reservations, modifications and cancellations are picked up from each OTA and pulled back into one system automatically. A true two-way API integration does both in real time; a weaker connection, such as a scheduled or manual calendar import, pushes on a delay measured in minutes or hours rather than seconds.
That gap is precisely why sync speed matters for overbooking. If a room sells on one channel and a second guest searches a different channel before the availability update arrives, both bookings can be confirmed for the same room. The faster the push, the smaller that window gets — which is the entire reason a channel manager exists rather than every property updating each OTA extranet by hand. FrontDesko's own OTA connections page documents pushing availability, rates and restrictions — stop-sell, minimum and maximum stay, and closed to arrival and departure — out in real time, with new reservations, modifications and cancellations flowing back automatically; see the full channel manager breakdown for how that connects to pricing tools. For what happens when the gap is too wide, see hotel overbooking management.
Common ARI Mistakes Small Hotels Make
Both are configuration problems, not software problems — but they show up as if the software is broken.
- Too many rate plans. Every additional rate plan is another set of restrictions to keep correct across every channel. Properties that spin up a new plan for every promotion end up with dozens of plans, most forgotten, some still carrying a stop sell or MinLOS from a sale that ended months ago. Fewer, well-understood rate plans are easier to keep accurate than many clever ones — see rack rate vs. BAR for how to structure a base plan before layering promotions on top.
- Mismatched room-type mapping. Each OTA maintains its own name and ID for a property's room types, and the channel manager has to map "Deluxe King" in the PMS to the equivalent listing on each OTA. If a mapping is wrong — pointing a channel's "Deluxe King" at the PMS's "Superior King" inventory pool, for instance — availability and restrictions sync perfectly and still apply to the wrong room, which looks like a software bug but is really a one-time setup error that was never corrected.
Frequently Asked Questions
What does ARI stand for in hotels?
ARI stands for Availability, Rates and Inventory. It is the set of data a property management system or channel manager sends to every connected OTA so each channel shows the same sellable rooms, the same prices and the same booking rules at the same time.
What is a stop sell in a hotel?
A stop sell closes a room type or rate plan for a specific date, making it unbookable everywhere it's pushed, regardless of how many rooms are actually still in inventory. It's a manual override used for maintenance, owner blocks, or protecting the last few rooms for a walk-in or VIP.
What is the difference between closed to arrival and closed to departure?
Closed to arrival (CTA) blocks new stays from starting on a specific date, though guests already in house can still leave that day. Closed to departure (CTD) blocks a stay from ending on a specific date, so anyone in house must stay through it. They solve opposite problems: CTA smooths a flood of arrivals, CTD prevents a flood of same-day checkouts on a sold-out night.
What is minimum length of stay (MinLOS) in a hotel?
Minimum length of stay (MinLOS) sets the fewest nights a guest must book depending on the arrival date. A MinLOS of 3 on a festival weekend means nobody can book just one or two nights starting that day, which protects high-demand dates from being filled with short, lower-yield stays.
What is the difference between MinLOS-arrival and MinLOS-through?
MinLOS-arrival only checks stays that start on the restricted date — a booking that begins earlier and simply passes through it is unaffected. MinLOS-through (also called stay-through or forward-stay) applies to any stay that includes that date at all, even if it started earlier, which closes the loophole of booking around the restriction.
What is a rate plan in a hotel?
A rate plan is a named pricing and policy package tied to a room type — covering the price, cancellation terms, what's included (breakfast, parking) and who can book it. The same Deluxe King room might be sold under a cheaper Non-Refundable plan and a pricier Flexible plan at the same time, each with its own rate and restrictions.
How fast does ARI need to update across OTAs?
As close to instant as the connection allows. The gap between a booking happening on one channel and every other channel reflecting the reduced availability is exactly the window in which the same room can be sold twice. A true two-way API connection updates within seconds; a scheduled or manual update can leave that gap open for hours.
What happens when ARI isn't synced correctly?
Overbookings, rate parity violations, and guests arriving to find no room, or the wrong price honoured on arrival. Most cases trace back to one of two causes: a slow or manual sync that updates channels minutes or hours apart, or a room-type mapping error where two different OTAs' versions of the "same" room don't actually share one inventory pool.
Sources
[1] Google, "Availability Message" — Hotel Prices developer guide, defining master/stop-sell restrictions, arrival/departure restrictions, length-of-stay and stay-through (forward-stay) restrictions, and booking-offset (minimum advance booking) restrictions: developers.google.com/hotels/hotel-prices/dev-guide/ari-availability-message.
[2] Uplisting Help Center, "Closed for Arrival (CFA) & Departure (CFD)," describing the CTA/CTD toggle and its sync across Airbnb, Booking.com, Vrbo and a direct booking site: support.uplisting.io/en/article/closed-for-arrival-cfa-departure-cfd-1e16h2m.
Stop Fixing ARI Mistakes After They Overbook a Room
Frontdesko pushes availability, rates and restrictions to every connected OTA in real time, with the PMS underneath it free forever.
Related Guides
Turn ARI into a working distribution setup
What Is a Channel Manager?
The software layer that actually keeps ARI consistent across every OTA, in plain English.
OTA Connections
Which booking portals Frontdesko connects to, and exactly what syncs in each direction.
Rack Rate vs. BAR
How to structure a base rate before layering rate plans and restrictions on top of it.