Answer:
Only to amortize intangible assets which are recognised as finite useful life. There are tow models, one is cost model, another is revaluation model. The way to charge intangible assets' amortisation is same as charging depreciation on physical non current assets.
Carrying amount (net book value) is equal cost or re-valuated amount less any subsequent accumulated amortisation and any impairment losses.
However, Revaluations should be regularly made so the carrying amount does not differ from the recoverable amount (it is the higher amount of net realisable value or value in use) at the end of the reporting period.
On the other hand, If the intangible assets are recognised as definite useful life, there is no need to charge amortisation on the profit and loss. But annually impairment test should be carried out. A impairment loss or a revaluation surplus will be adjusted on both income statement and balance sheet.
Hope it is helpful!