The term Block Allotment is used in the Travel industry to designate a certain block of pre-negotiated rooms, Flights/seats, and rental cars that have been bought out and held by a third party such as a travel wholesaler, tour operator, travel agent, or Online Travel Agent such as Priceline, etc. Allotments can be contracted with a tour operator or an OTA for a specific period such as a whole season, part of a season, or for any single date, and then resold to travel partners and final customers around the globe. A few days before guest arrival unsold flights, rooms, or rental cars may be released back to the supplier if such an agreement exists between the two parties. An allotment release back period is also negotiated as part of the allotment contract (e.g. four days before arrival). This frame of time is called the release period or cut-off date. Once this cutoff date occurs OTA’s no longer have that inventory available on its website until the new Block Allotment period goes into effect which is usually less than a day. In the transition from one Allottment Period to another, one OTA’s website may not have the same inventory available as another.