Amortisation is the gradual spreading of a cost across time. In company accounts it usually means allocating the cost of an intangible asset, such as a licence or software, to profit and loss over the period it is expected to generate benefits.
The word is also used for loans, where amortisation is the step‑by‑step repayment of principal through regular instalments. Same term, two related ideas: a planned reduction over time.
What amortisation means in company accounts
In financial statements, amortisation is the non‑cash expense that reduces the carrying value of an intangible asset with a finite life, and records a matching charge in the income statement each period. Tangible assets like machines are depreciated. Intangible assets like patents, customer lists and software are amortised.
When a business pays for an intangible that will help it for several years, accounting rules do not usually allow the full cost to hit profit immediately. Instead, the asset goes on the balance sheet and is then amortised over its useful life. This aligns cost with revenue, which helps investors compare performance across periods.
Goodwill, which often arises after an acquisition, is typically not amortised under major accounting standards. It is tested for impairment, meaning it is written down only if its value has fallen. Other intangibles with indefinite lives are treated the same way. Exact rules vary by accounting framework and jurisdiction.
How the expense is calculated
The most common approach is straight‑line amortisation. You estimate the asset’s useful life, subtract any expected residual value, and spread the remainder evenly.
- Straight‑line example: A company buys a five‑year licence for £10 million with no residual value. Annual amortisation is £2 million, recorded as an expense each year. On the balance sheet, the licence starts at £10 million and falls by £2 million per year to zero at the end of year five.
- Accelerated patterns: If the asset’s benefits are front‑loaded, a faster pattern can be used so more expense is recognised early on. The method chosen should reflect how the asset is consumed.
- Impairment interaction: If the recoverable amount drops below the carrying value at any point, an impairment loss may be recognised in addition to regular amortisation.
Amortisation is a non‑cash charge in the period. You will usually see it added back in the operating section of the cash flow statement. Analysts also focus on EBITDA, which excludes depreciation and amortisation expenses, to compare operating performance before non‑cash charges. That said, cash was spent upfront to acquire the asset, and future replacements may require cash again, so the charge is not irrelevant to long‑term economics.
Accounting and tax treatments can differ, and tax rules can change. Companies may report one amortisation pattern in accounts while using another to calculate taxable profit, depending on local regulations.
Loan amortisation and payment schedules
For borrowing, amortisation is the process of paying down principal through regular instalments that also include interest. An amortisation schedule lists every payment, showing how much goes to interest and how much reduces the outstanding balance.
In a typical repayment loan, earlier instalments are interest‑heavy because interest is charged on a larger outstanding principal. Over time, as the balance falls, less of each payment is interest and more is principal.
- Illustrative pattern: Suppose a borrower takes a fixed‑rate loan with equal monthly payments over several years. The first payment might be, say, £1,000 in total, of which £700 is interest and £300 is principal reduction. A year later, the £1,000 payment might break down as £600 interest and £400 principal, because the outstanding balance is lower.
- Prepayments: Extra payments reduce principal faster, which can shorten the loan term or lower later instalments, depending on the lender’s rules.
- Negative amortisation: If a scheduled payment is smaller than the interest due, unpaid interest is added to the principal. The balance grows rather than shrinks, which increases future interest costs.
Credit agreements differ. Some loans are interest‑only for a period before switching to amortising payments, and some allow flexible overpayments or holidays. The exact behaviour depends on the product and provider.
Amortisation in bonds and structured products
Fixed‑income investors also meet amortisation in two places:
- Premium and discount amortisation: If you buy a bond above par (a premium), accounting will gradually amortise that premium down to par by maturity. This reduces the carrying value and the recognised interest income over time. If you buy below par (a discount), the discount is accreted, which increases carrying value and recognised interest income. The effective interest method is commonly used to match yield with cash flows.
- Amortising securities: Some instruments, such as certain asset‑backed securities or mortgage‑backed securities, repay principal throughout the life of the deal. Cash flows include both interest and scheduled or prepaid principal, so the outstanding balance amortises over time. Prepayment speeds can change the timing of amortisation, which affects yield.
Where investors will see it reported
In company reporting, look for these lines and notes:
- Income statement: An amortisation expense line, sometimes grouped with depreciation. Sector practice varies on whether it is shown within operating costs or separately.
- Balance sheet: Intangible assets shown net of accumulated amortisation. Notes usually disclose original cost, movements and remaining useful lives.
- Cash flow statement: Amortisation added back in operating cash flows because it is non‑cash in the period.
- Non‑GAAP measures: Management may present results before amortisation of acquired intangibles to highlight underlying trends. Read the reconciliations to see what has been excluded.
For loans and fixed income, amortisation appears in lender statements, amortisation schedules, and yield calculations that assume premium or discount amortisation through to maturity or call dates.
Amortisation, depreciation and impairment compared
- Amortisation: Systematic expense of an intangible asset with a finite life, or scheduled repayment of loan principal.
- Depreciation: Systematic expense of a tangible asset such as equipment or vehicles.
- Impairment: A write‑down when an asset’s recoverable amount falls below its carrying value. It is not a regular schedule and can apply to both tangible and intangible assets, including goodwill.
All three reduce reported profit when they occur, but they tell different economic stories. Amortisation and depreciation reflect planned consumption of assets over time. Impairment signals an adverse change in expected benefits.
For valuation work, understanding which expenses are recurring and which are one‑offs helps. An investor may adjust for amortisation of acquired intangibles when comparing two businesses, while still recognising that cash was paid for those assets at some point. Context matters as accounting policies, tax rules and industry norms differ.