What is amortisation?

Amortisation (definition)

Amortisation is the depreciation of intangible assets for bookkeeping and tax purposes. It can also refer to the reduction of a loan over time.

Amortisation is how a business records the purchase of an intangible asset in its accounting records and on its tax returns. The purchase price is written off gradually over the asset’s useful life. Amortisation can also refer to paying down a debt over time.

What is asset amortisation vs loan amortisation

When a business buys an asset, it typically writes off the cost over time rather than all at once. For physical (or tangible) assets, this process is called depreciation. For intangible assets like patents, trademarks, copyrights or goodwill, the process is called amortization.

Paying down a debt is referred to as loan amortisation. While it’s important to understand loan amortisation, this glossary definition deals with asset amortisation.

Why asset amortisation matters

Amortisation gives businesses a better sense of their profit and loss from year to year. Writing off the full value of an asset at the time of purchase would make profits look artificially low for that year.

Say a business buys a 20-year patent for $100,000. If it wrote off the full value of the patent straight away, its profit would dip $100,000 in that year alone. In subsequent years, profits would look a lot higher even though the business is still getting value from the asset. Amortising the asset by $5000 every year for 20 years better distributes the cost so the business can see its profitability from year to year.

How amortisation works

The business records the full value of the asset on its balance sheet at the time of purchase. At the end of every year, it amortises that asset to reflect its loss of value over time.

The amount amortised is reflected on the balance sheet and is recorded as an expense on the profit and loss statement. Recording amortisation as an expense helps to lower taxes.

This process continues throughout the useful life of the asset. So if it’s a patent, it continues until the patent expires.

How to calculate amortisation

Amortising assets is complicated and the formula may change depending on the amortisation method being used. The process starts by recording the purchase price of the asset and then amortising a certain amount each year. The amount amortised depends on:

  • the value of the asset
  • the asset’s lifespan (this number may be set by the tax office)
  • the amortisation method being used (which is also subject to rules)

Some accounting software will automate these calculations but the input must be correct and compliant with rules set by the IRAS.

Consult with an accountant or bookkeeper to avoid costly mistakes. You can find one in the Xero advisor directory.

Four common methods of amortisation

As noted, the IRAS sets rules about which amortisation methods can be used in given situations. Always consult with an expert before choosing a method.

  1. Straight-line amortisation: An equal portion of the asset's value is amortised each year of its useful life. For example, a $150,000 asset with a 15-year lifespan would be amortised $10,000 per year.
  2. Declining balance method: The asset is amortised more during the early years of its life and by lower amounts in subsequent years. For example, if the asset costs $10,000 the business might amortise at a rate of 30% per year. That would equate to $3000 the first year. The following year, the remaining value would be $7000, so 30% amortisation would be $2100. This pattern would continue until the asset is fully amortised.
  3. Double declining balance method: This is a form of declining balance where the rate of amortisation is set in a certain way. Specifically, the rate is calculated by dividing the number 2 by the useful life of the asset. So an asset with a useful life of 5 years would be amortised at 40% (2 / 5 x 100 = 40%) per year.
  4. Annuity method: The asset is amortised according to how much money it earns the business in a given year. This requires a model for figuring out the lifetime income the asset will generate. As a result, it’s the most complex of all the methods.

Amortisation vs depreciation

Amortisation and depreciation work the same. Amortisation is the word used for intangible assets, which are non-physical things like patents, copyrights and licences. Depreciation is for tangible assets, which are physical things like vehicles, tools, and equipment.

See related terms

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This glossary is for small business owners. The definitions are written with their requirements in mind. More detailed definitions can be found in accounting textbooks or from an accounting professional. Xero does not provide accounting, tax, business or legal advice.