Intangible assets must be written off over the useful economic life of the intangible asset.

Where in exceptional cases the useful life of intangible assets cannot be reliably estimated, such assets must be written off over a period chosen by the directors of the company.

The period referred to in sub-paragraph (2) must not exceed ten years.

There must be disclosed in a note to the accounts the period referred to in sub-paragraph (2) and the reasons for choosing that period.