What it means
Amortise means to spread a cost or value over time, and in accounting it describes how a balance changes gradually rather than all at once. Amortised cost applies this idea to financial instruments such as loans, bonds, and receivables that a business holds in order to collect payments.
Under IFRS 9 and US GAAP, many of these instruments are measured at amortised cost rather than at their current market price. For a loan, amortised cost tracks the balance still outstanding after each repayment, so the balance sheet shows what the business really owes.
Any fees paid to arrange the loan can be built into the carrying amount and spread over its life in the same way. This is why the figure on the books can differ from the cash paid in any single month.
For bonds, the concept deals with the gap between the price paid and the face value repaid at maturity. A bond bought at a discount is recorded at a lower value, and that discount is gradually recognised as interest income until the bond matures at face value.
The effective interest method does this at a steady rate, although simple examples often spread the discount evenly for clarity. Amortised cost is not the same as depreciation, which spreads the cost of a physical asset such as a van or machine over its useful life.
Amortisation of intangible assets, such as software licences, is a related but separate rule for spreading the cost of non-physical items. Keep the distinction in mind, because the two terms are often mixed up in management reports.
For non-finance managers, amortised cost explains why the profit and loss statement can differ from the bank balance. Non-cash entries, such as the gradual unwinding of a discount, change reported earnings without money physically leaving or entering the business.
Knowing this helps you ask sharper questions when the finance team presents results.
In practice
Real-world examples
Example 1
A small business takes out a $50,000 bank loan repayable over five years. Under amortised cost, the balance sheet shows the principal still owed after each scheduled repayment, not the original $50,000. The interest paid on the loan is recorded as a finance cost in the profit and loss statement, separate from the balance owed. Each repayment reduces the balance, so the balance sheet always reflects the current debt.
Example 2
An investor buys a $100,000 corporate bond for $95,000 with five years to maturity. Its amortised cost starts at $95,000 and rises by $1,000 a year as the discount unwinds. At maturity the carrying amount equals the $100,000 repaid, so there is no further gain or loss on the balance sheet.
Example 3
A software company buys a five-year software licence for $10,000 upfront. Because the licence is an intangible asset rather than a financial instrument, the company amortises it straight-line, recording $2,000 a year as an expense. This is amortisation of an intangible asset, which is related to, but separate from, amortised cost.
Think of it
Imagine buying a massive block of high-end cheese to eat over a year. Instead of counting the whole block as eaten on day one, you slice off a small piece each week to match your actual consumption.
Formula
Calculation
Amortised Cost = Initial Amount + Discount Amortised to Date - Principal Repaid. For example, a company buys a $100,000 bond that matures in five years for $95,000, so the $5,000 discount is spread evenly at $1,000 per year. After one year the amortised cost is $95,000 + $1,000 = $96,000, and after two years it is $97,000. By maturity the amortised cost reaches the full $100,000 face value, and this example assumes straight-line spreading for simplicity.Case study
Seen in the real world
This is a fictional, illustrative scenario. Riverside Catering, a small events business, invested $38,000 in bonds with a combined face value of $40,000. The bonds mature in four years and pay 5% interest on the face value each year. The finance manager recorded the bonds at amortised cost, so the $2,000 discount is spread over the four years at $500 a year.
At the end of year one, the amortised cost of the bonds was $38,500, which is the figure the balance sheet reports. The bonds paid $2,000 of cash interest, and the $500 discount amortisation was added to that income, giving $2,500 of interest income for the year. Market prices of similar bonds moved during the year, but those movements did not change the reported figure. This case uses straight-line spreading for simplicity, which approximates the effective interest method.
The finance manager explained to the board that the bonds would reach their $40,000 face value at maturity on a steady, predictable path. The board appreciated that reported income was not distorted by short-term market swings. The finance manager also reminded the board that the approach only fits bonds the company intends to hold until they mature. If the company planned to sell them, a different measurement basis would apply.
Watch out
Common mistakes
- Assuming amortised cost represents the current market value of an asset.
- Confusing the amortised cost of a loan with the total amount of cash paid including interest.
- Failing to update the amortised book value on financial statements at the end of each reporting period.
Questions
People also ask
Is amortised cost the same as cash flow?
No. Amortised cost spreads income and expenses on paper over time, while cash flow tracks actual money entering and leaving the business.
Why do we use amortised cost instead of market value?
Market values fluctuate constantly, which would make financial planning unpredictable, so amortised cost gives a stable, reliable historical baseline.
Does every asset use amortised cost?
No. Physical assets such as vans and machinery are depreciated instead, and land is not depreciated because it does not wear out.