When is the right time to test non current asset for impairment?

AT the period end or when any external or internal signs show they the asset may be impaired.

according to international reporting financial standards non current asset should be reviewed for impairment annually........

At the end of each reporting period, an entity is required to assess whether there is any indication that an asset may be impaired (i.e. its carrying amount may be higher than its recoverable amount).

The recoverable amounts of the following types of intangible assets are measured annually whether or not there is any indication that it may be impaired. In some cases, the most recent detailed calculation of recoverable amount made in a preceding period may be used in the impairment test for that asset in the current period.an intangible asset with an indefinite useful life an intangible asset not yet available for use goodwill acquired in a business combination