What Is an Amortized Bond?

An amortized bond is one in which the principal (face value) on the debt is paid down regularly, along with its interest expense over the life of the bond. A fixed-rate residential mortgage is one common example because the monthly payment remains constant over its life of, say, 30 years. However, each payment represents a slightly different percentage mix of interest versus principal. An amortized bond is different from a balloon or bullet loan, where there is a large portion of the principal that must be repaid only at its maturity.

Understanding Amortized Bonds

The principal paid off over the life of an amortized loan or bond is divvied up according to an amortization schedule, typically through calculating equal payments all along the way. This means that in the early years of a loan, the interest portion of the debt service will be larger than the principal portion. As the loan matures, however, the portion of each payment that goes towards interest will become lesser and the payment to principal will be larger. The calculations for an amortizing loan are similar to that of an annuity using the time value of money, and can be carried out quickly using an amortization calculator.

Amortization of debt affects two fundamental risks of bond investing. First, it greatly reduces the credit risk of the loan or bond because the principal of the loan is repaid over time, rather than all at once upon maturity, when the risk of default is the greatest. Second, amortization reduces the duration of the bond, lowering the debt’s sensitivity to interest rate risk, as compared with other non-amortized debt with the same maturity and coupon rate. This is because as time passes, there are smaller interest payments, so the weighted-average maturity (WAM) of the cash flows associated with the bond is lower.

Example of Amortizing a Bond

30-year fixed-rate mortgages are amortized so that each monthly payment goes towards interest and principal. Say you purchase a home with a $400,000 30-year fixed-rate mortgage with a 5% interest rate. The monthly payment is $2,147.29, or $25,767.48 per year.

At the end of year one, you have made 12 payments, most of the payments have been towards interest, and only $3,406 of the principal is paid off, leaving a loan balance of $396,593. The next year, the monthly payment amount remains the same, but the principal paid grows to $6,075. Now fast forward to year 29 when $24,566 (almost all of the $25,767.48 annual payments) will go towards principal. Free mortgage calculators or amortization calculators are easily found online to help with these calculations quickly.

Straight-Line vs. Effective-Interest Method of Amortization

Treating a bond as an amortized asset is an accounting method used by companies that issue bonds. It allows issuers to treat the bond discount as an asset over the life of the bond until its maturity date. A bond is sold at a discount when a company sells it for less than its face value and sold at a premium when the price received is greater than face value.

If a bond is issued at a discount—that is, offered for sale below its par or face value—the discount must be treated either as an expense or it can be amortized as an asset. In this way, an amortized bond is used specifically for tax purposes because the amortized bond discount is treated as part of a company’s interest expense on its income statement. The interest expense, a non-operating cost, reduces a company’s earnings before tax (EBT) and, therefore, the amount of its tax burden.

Effective-interest and straight-line amortization are the two options for amortizing bond premiums or discounts. The easiest way to account for an amortized bond is to use the straight-line method of amortization. Under this method of accounting, the bond discount that is amortized each year is equal over the life of the bond.

Companies may also issue amortized bonds and use the effective-interest method. Rather than assigning an equal amount of amortization for each period, effective-interest computes different amounts to be applied to interest expense during each period. Under this second type of accounting, the bond discount amortized is based on the difference between the bond’s interest income and its interest payable. Effective-interest method requires a financial calculator or spreadsheet software to derive.

What Is the Amortization of Intangibles?

Amortization of intangibles, also simply known as amortization, is the process of expensing the cost of an intangible asset over the projected life of the asset for tax or accounting purposes. Intangible assets, such as patents and trademarks, are amortized into an expense account called amortization. Tangible assets are instead written off through depreciation. The amortization process for corporate accounting purposes may differ from the amount of amortization used for tax purposes.

Understanding the Amortization of Intangibles

For tax purposes, the cost basis of an intangible asset is amortized over a specific number of years, regardless of the actual useful life of the asset (as most intangibles don’t have a set useful life). The Internal Revenue Service (IRS) allows intangibles to be amortized over a 15-year period if it’s one of the ones included in Section 197.

Intangible assets are non-physical assets that can be assigned an economic value. Intellectual property (IP) is considered to be an intangible asset and is a broad term that encompasses most intangible assets. Most IP is covered under Section 197. Examples of these Section 197 intangible assets include patents, goodwill, trademarks, and trade and franchise names.

Not all IP is amortized over the 15-year period set by the IRS, however. There are certain exclusions, such as software acquired in a transaction that is readily available for purchase by the general public, subject to a nonexclusive license, and has not been substantially modified. In those cases and select others, the intangibles are amortized under Section 167.

Special Considerations

When a parent company purchases a subsidiary company and pays more than the fair market value (FMV) of the subsidiary’s net assets, the amount over fair market value is posted to goodwill (an intangible asset). IP is initially posted as an asset on the firm’s balance sheet when it is purchased.

IP can also be internally generated by a company’s own research and development (R&D) efforts. For instance, a company may win a patent for a newly developed process, which has some value. That value, in turn, increases the value of the company and so must be recorded appropriately.

In either case, the process of amortization allows the company to write off annually a part of the value of that intangible asset according to a defined schedule.

Amortization vs. Depreciation

Assets are used by businesses to generate revenue and produce income. Over a period of time, the costs related to the assets are moved into an expense account as the useful life of the asset dwindles. By expensing the cost of the asset over a period of time, the company is complying with GAAP, which requires the matching of revenue with the expense incurred to generate the revenue.

Tangible assets are expensed using depreciation, and intangible assets are expensed through amortization. Depreciation generally includes a salvage value for the physical asset—the value that the asset can be sold for at the end of its useful life. Amortization doesn’t take into account a salvage value.

Types of Amortization

For accounting (financial statement) purposes, a company can choose from six amortization methods: straight line, declining balance, annuity, bullet, balloon, and negative amortization. There are only four depreciation methods that can be used for accounting purposes: straight line, declining balance, sum-of-the-years’ digits, and units of production.

For tax purposes, there are two options for amortization of intangibles that the IRS allows. These are straight line and the income forecast method. The income forecast method can be used instead of the straight-line method if the asset is: motion picture films, videotapes, sound recordings, copyrights, books, or patents. For depreciation of physical assets, the IRS only allows the Modified Accelerated Cost Recovery System (MACRS).

Example of Amortization

Assume, for example, that a construction company buys a $32,000 truck to contractor work, and that the truck has a useful life of eight years. The annual depreciation expense on a straight-line basis is the $32,000 cost basis minus the expected salvage value—in this case, $4,000—divided by eight years. The annual deprecation for the truck would be $3,500 per year, or ($32,000 – $4,000) ÷ 8.

On the other hand, assume that a corporation pays $300,000 for a patent that allows the firm exclusive rights over the intellectual property for 30 years. The firm’s accounting department posts a $10,000 amortization expense each year for 30 years.

Both the truck and the patent are used to generate revenue and profit over a particular number of years. Since the truck is a physical asset, depreciation is used, and since the rights are intangible, amortization is used.

What Is an Amortized Loan?

An amortized loan is a type of loan with scheduled, periodic payments that are applied to both the loan’s principal amount and the interest accrued. An amortized loan payment first pays off the relevant interest expense for the period, after which the remainder of the payment is put toward reducing the principal amount. Common amortized loans include auto loans, home loans, and personal loans from a bank for small projects or debt consolidation.

How an Amortized Loan Works

The interest on an amortized loan is calculated based on the most recent ending balance of the loan; the interest amount owed decreases as payments are made. This is because any payment in excess of the interest amount reduces the principal, which in turn, reduces the balance on which the interest is calculated. As the interest portion of an amortized loan decreases, the principal portion of the payment increases. Therefore, interest and principal have an inverse relationship within the payments over the life of the amortized loan.

An amortized loan is the result of a series of calculations. First, the current balance of the loan is multiplied by the interest rate attributable to the current period to find the interest due for the period. (Annual interest rates may be divided by 12 to find a monthly rate.) Subtracting the interest due for the period from the total monthly payment results in the dollar amount of principal paid in the period.

The amount of principal paid in the period is applied to the outstanding balance of the loan. Therefore, the current balance of the loan, minus the amount of principal paid in the period, results in the new outstanding balance of the loan. This new outstanding balance is used to calculate the interest for the next period.

Amortized Loans vs. Balloon Loans vs. Revolving Debt (Credit Cards)

While amortized loans, balloon loans, and revolving debt–specifically credit cards–are similar, they have important distinctions that consumers should be aware of before signing up for one.

Amortized Loans

Amortized loans are generally paid off over an extended period of time, with equal amounts paid for each payment period. However, there is always the option to pay more, and thus, further reduce the principal owed.

Balloon Loans

Balloon loans typically have a relatively short term, and only a portion of the loan’s principal balance is amortized over that term. At the end of the term, the remaining balance is due as a final repayment, which is generally large (at least double the amount of previous payments).

Revolving Debt (Credit Cards) 

Credit cards are the most well-known type of revolving debt. With revolving debt, you borrow against an established credit limit. As long as you haven’t reached your credit limit, you can keep borrowing. Credit cards are different than amortized loans because they don’t have set payment amounts or a fixed loan amount.

Example of an Amortization Loan Table

The calculations of an amortized loan may be displayed in an amortization table. The table lists relevant balances and dollar amounts for each period. In the example below, each period is a row in the table. The columns include the payment date, principal portion of the payment, interest portion of the payment, total interest paid to date, and ending outstanding balance. The following table excerpt is for the first year of a 30-year mortgage in the amount of $165,000 with an annual interest rate of 4.5%

What Is an Amortization Schedule?

Amortizing loans feature level payment amounts over the life of the loan, but with varying proportions of interest and principal making up each payment. A traditional mortgage is a prime example of such a loan.

A loan amortization schedule represents the complete table of periodic loan payments, showing the amount of principal and interest that comprise each level payment until the loan is paid off at the end of its term. Early in the schedule, the majority of each payment goes toward interest; later in the schedule, the majority of each payment begins to cover the loan’s remaining principal.

Understanding an Amortization Schedule

If you are taking out a mortgage or auto loan, your lender should provide you with a copy of your loan amortization schedule so you can see at a glance what the loan will cost and how the principal and interest will be broken down over its life.

In a loan amortization schedule, the percentage of each payment that goes toward interest diminishes a bit with each payment and the percentage that goes toward principal increases. Take, for example, a loan amortization schedule for a $165,000, 30-year fixed-rate mortgage with a 4.5% interest rate:

Amortization schedules can be customized based on your loan and your personal circumstances. With more sophisticated amortization calculators, like the templates you can find in Excel you can compare how making accelerated payments can accelerate your amortization. If for example, you are expecting an inheritance, or you get a set yearly bonus, you can use these tools to compare how applying that windfall to your debt can affect your loan’s maturity date and your interest cost over the life of the loan.

In addition to mortgages, car loans and personal loans are also amortizing for a term set in advance, at a fixed interest rate with a set monthly payment. The terms vary depending on the asset. Most conventional home loans are 15- or 30-year terms. Car owners often get an auto loan that will be repaid over five years or less. For personal loans, three years is a common term.

Formulas Used in Amortization Schedules

Borrowers and lenders use amortization schedules for installment loans that have payoff dates that are known at the time the loan is taken out, such as a mortgage or a car loan. There are specific formulas that are used to develop a loan amortization schedule. These formulas may be built into the software you are using, or you may need to set up your amortization schedule from scratch.

If you know the term of a loan and the total periodic payment amount, there is an easy way to calculate a loan amortization schedule without resorting to the use of an online amortization schedule or calculator. The formula to calculate the monthly principal due on an amortized loan is as follows:

Principal Payment = Total Monthly Payment – [Outstanding Loan Balance x (Interest Rate / 12 Months)]

To illustrate, imagine a loan has a 30-year term, a 4.5% interest rate, and a monthly payment of $1,266.71. Starting in month one, multiply the loan balance ($250,000) by the periodic interest rate. The periodic interest rate is one-twelfth of 4.5% (or 0.00375), so the resulting equation is $250,000 x 0.00375 = $937.50. The result is the first month’s interest payment. Subtract that amount from the periodic payment ($1,266.71 – $937.50) to calculate the portion of the loan payment allocated to the principal of the loan’s balance ($329.21).

To calculate the next month’s interest and principal payments, subtract the principal payment made in month one ($329.21) from the loan balance ($250,000) to get the new loan balance ($249,670.79), and then repeat the steps above to calculate which portion of the second payment is allocated to interest and which is allocated to the principal. You can repeat these steps until you have created an amortization schedule for the full life of the loan.

An Easier Way to Calculate an Amortization Schedule

Calculating an amortization schedule is as simple as entering the principal, interest rate, and loan term into a loan amortization calculator. But you can also calculate it by hand if you know the rate on the loan, the principal amount borrowed, and the loan term.

How to Calculate the Total Monthly Payment

Typically, the total monthly payment is specified by your lender when you take out a loan. However, if you are attempting to estimate or compare monthly payments based on a given set of factors, such as loan amount and interest rate, you may need to calculate the monthly payment as well.

If you need to calculate the total monthly payment for any reason, the formula is as follows:

Total Monthly Payment = Loan Amount [ i (1+i) ^ n / ((1+i) ^ n) – 1) ]

where:

• i = monthly interest rate. You’ll need to divide your annual interest rate by 12. For example, if your annual interest rate is 6%, your monthly interest rate will be .005 (.06 annual interest rate / 12 months).
• n = number of payments over the loan’s lifetime. Multiply the number of years in your loan term by 12. For example, a 30-year mortgage loan would have 360 payments (30 years x 12 months).

Using the same example from above, we will calculate the monthly payment on a $250,000 loan with a 30-year term and a 4.5% interest rate. The equation gives us $250,000 [(0.00375 (1.00375) ^ 360) / ((1.00375) ^ 360) – 1) ] = $1,266.71. The result is the total monthly payment due on the loan, including both principal and interest charges.

30-Year vs. 15-Year Amortization Table

If a borrower chooses a shorter amortization period for their mortgage—for example, 15 years—they will save considerably on interest over the life of the loan, and they will own the house sooner. That’s because they’ll make fewer payments for which interest will be amortized. Additionally, interest rates on shorter-term loans are often at a discount compared to longer-term loans.

There is a tradeoff, however. A shorter amortization window increases the monthly payment due on the loan. Short amortization mortgages are good options for borrowers who can handle higher monthly payments without hardship; they still involve making 180 sequential payments (15 years x 12 months).

It’s important to consider whether or not you can maintain that level of payment based on your current income and budget.

Using an amortization calculator can help you compare loan payments against potential interest savings for a shorter amortization to decide which option suits you best. Here’s what a $500,000 loan with a 6% interest rate would look like, with a hypothetical 30-year and 15-year schedule to compare: