Article 67 of the Regulations for the Implementation of the Enterprise Income Tax Law of People's Republic of China (PRC) stipulates that the amortization period of intangible assets shall not be less than 10 year. As the investor or transferee of intangible assets, if the relevant laws or contracts stipulate the service life, it can be amortized in installments according to the stipulated or agreed service life. Therefore, the above intangible assets of your company can be amortized for five years according to the time stipulated in the contract.
According to the provisions of Caishui [2008] 1, software purchased by enterprises and institutions that meet the confirmation conditions of fixed assets or intangible assets can be accounted for as fixed assets or intangible assets, and the depreciation or amortization period can be appropriately shortened to 2 years with the approval of the competent tax authorities.
So how long it takes to amortize depends on the specific situation.
I hope I can help you!