Amortisation (or amortization) is the process of decreasing or accounting for an amount; over a period. The word comes from Middle English amortisen to kill, alienate in mortmain, from Anglo-French amorteser, alteration of amortir, from Vulgar Latinadmortire "to kill", from Latinad- and mort-, "death".
When used in the context of a home purchase, amortization is the process by which loan principal decreases over the life of a loan, typically an amortizing loan. With each mortgage payment that is made, a portion of the payment is applied towards reducing the principal, and another portion of the payment is applied towards paying the interest on the loan. An amortization schedule, a table detailing each periodic payment on a loan, shows this ratio of principal and interest and demonstrates how a loan's principal amount decreases over time. An amortization schedule can be generated by an amortization calculator. Negative amortization is an amortization schedule where the loan amount actually increases through not paying the full interest.
In business, amortization allocates a lump sum amount to different time periods, particularly for loans and other forms of finance, including related interest or other finance charges. Amortization is also applied to capital expenditures of certain assets under accounting rules, particularly intangible assets, in a manner analogous to depreciation.
In the context of zoning regulations, amortization refers to the time period a non conforming property has to conform to a new zoning classification before the non-conforming use becomes prohibited. For example, if the city rezones property from industrial to residential and sets an amortization period of one year, all property within the rezoned boundary must move from industrial use to residential use within one year.