What is ARI (availability, rates, inventory)?
ARI stands for availability, rates and inventory — the three pieces of information a channel manager keeps in sync between your property and every OTA you sell on.
The three parts of ARI
Availability: whether a room type can be booked for a given date — open or closed for sale.
Rates: the price for that room type and date, including any rate plan rules such as minimum stay or non-refundable vs flexible.
Inventory: how many units of a room type exist and how many are left to sell for a given date — relevant for room types with several identical units (say, 6 Standard Double rooms), as opposed to availability, which can be a simple yes/no for a single unique room.
Why ARI needs to move together, not separately
If only rates sync but inventory doesn't, an OTA can keep selling a room type after it's actually full. If only availability syncs but not rates, a price change on one channel won't show up on others, which can quietly break rate parity (see our rate parity glossary page). ARI is usually described as one combined feed precisely because the three pieces only make sense kept in sync with each other, in near real time, across every channel at once.
ARI in practice
| Term | What changes it | What happens if it's wrong |
|---|---|---|
| Availability | A room type opens or closes for sale on a date | An OTA can still take a booking for a room that's actually sold out → overbooking |
| Rate | You change a price, or a rate plan rule changes | A channel shows an outdated price → lost revenue or a guest dispute at check-in |
| Inventory | A unit's remaining count for a date | Multi-unit room types oversell past the number of physical rooms you actually have |
Where ARI comes from
Most channel managers and OTAs exchange ARI over an XML or API connection, sometimes through a connectivity partner that both sides certify against, pushed whenever something changes on either side rather than on a fixed schedule — though sync speed and reliability vary by OTA and by channel manager.
How Prime Host handles ARI
One ARI feed for the calendar and the booking engine
The same availability, rates and inventory that drive your calendar also drive your direct booking engine, so there's one source of truth instead of two systems that can drift apart.
Confirmed, not assumed
Every ARI update is read back from the channel before Prime Host marks it done.
Bulk changes without breaking sync
Rate and availability changes across many dates and channels at once are checked against min/max guardrails so a bulk edit doesn't silently go wrong.
Frequently asked questions
What does ARI stand for?
Availability, rates and inventory — the three things a channel manager keeps synced between your property and every OTA.
What's the difference between availability and inventory?
Availability is whether a room type can be booked at all on a date. Inventory is how many units are left, for room types that have more than one identical room.
How often does ARI update across channels?
It varies by OTA and connection — most push on every change rather than a fixed schedule, but the real speed depends on both sides.
What happens if ARI gets out of sync?
Overbooking, lost sales from a stale high price, or rate parity problems.
Do I need to update ARI manually on each OTA?
Not if you use a channel manager connected to all your channels — you update once, centrally.
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