An Airport Slot is the permission granted by an airport authority to airline operators for landing and taking off (Slot-Pair). The allocation of a slot also grants the airline operators the use of all necessary airport infrastructure and services. In business valuation, an airport slot is one of the important intangible assets which some airline operators collateralise to raise debt on the financial market. Airport slots qualify as intangible assets because they can be recognised, identified and the economic value accurately measured. Airport slots give airlines a competitive advantage and incremental economic benefits to the owners. Business valuators estimate the fair market value of airport slots by applying techniques under the cost, market, and income methods.