In business, amortization refers to spreading payments over multiple periods. The term is used for two separate processes: amortization of loans and amortization of assets. In the latter case it refers to allocating the cost of an intangible asset over a period of time.

## Amortization of loans

In lending, amortization is the distribution of loan repayments into multiple cash flow installments, as determined by an amortization schedule. Unlike other repayment models, each repayment installment consists of both principal and interest. Amortization is chiefly used in loan repayments (a common example being a mortgage loan) and in sinking funds. Payments are divided into equal amounts for the duration of the loan, making it the simplest repayment model. A greater amount of the payment is applied to interest at the beginning of the amortization schedule, while more money is applied to principal at the end. Commonly it is known as EMI or Equated Monthly Installment.[1]

${\displaystyle P\,=\,A\cdot {\frac {1-\left({\frac {1}{1+r}}\right)^{n}}{r}}}$

or, equivalently,

${\displaystyle A\,=\,P\cdot {\frac {r(1+r)^{n}}{(1+r)^{n}-1}}}$

where: P is the principal amount borrowed, A is the periodic amortization payment, r is the periodic interest rate divided by 100 (nominal annual interest rate also divided by 12 in case of monthly installments), and n is the total number of payments (for a 30-year loan with monthly payments n = 30 × 12 = 360).

## Negative amortization

Negative amortization (also called deferred interest) occurs if the payments made do not cover the interest due. The remaining interest owed is added to the outstanding loan balance, making it larger than the original loan amount.

If the repayment model for a loan is "fully amortized", then the very last payment (which, if the schedule was calculated correctly, should be equal to all others) pays off all remaining principal and interest on the loan. If the repayment model on a loan is not fully amortized, then the last payment due may be a large balloon payment of all remaining principal and interest. If the borrower lacks the funds or assets to immediately make that payment, or adequate credit to refinance the balance into a new loan, the borrower may end up in default.

## Amortization of intangible assets

In accounting, amortization refers to expensing the acquisition cost minus the residual value of intangible assets in a systematic manner over their estimated "useful economic lives" so as to reflect their consumption, expiry, and obsolescence, or other decline in value as a result of use or the passage of time.

Depreciation is a corresponding concept for tangible assets. Methodologies for allocating amortization to each accounting period are generally the same as these for depreciation. However, many intangible assets such as goodwill or certain brands may be deemed to have an indefinite useful life and are therefore not subject to amortization (although goodwill is subjected to an impairment test every year).

While theoretically amortization is used to account for the decreasing value of an intangible asset over its useful life, in practice many companies will amortize what would otherwise be one-time expenses through listing them as a capital expense on the cash flow statement and paying off the cost through amortization, having the effect of improving the company's net income in the fiscal year or quarter of the expense.[2]

Amortization is recorded in the financial statements of an entity as a reduction in the carrying value of the intangible asset in the balance sheet and as an expense in the income statement.

Under International Financial Reporting Standards, guidance on accounting for the amortization of intangible assets is contained in IAS 38.[3] Under United States generally accepted accounting principles (GAAP), the primary guidance is contained in FAS 142.[4]