First, you need to know the estimated useful life of the asset. Let us say, you purchased the asset on 01 January 2011and the estimated useful life is 5 years, then the asset is fully depreciated. You still have to recognize the depreciation but instead of debiting depreciation expense, retained earnings account should be used since it pertain to previous years.
However, if the estimated useful life of the asset is 6 years, then the entry should debit retained earnings for the 5 years from 01 January 2011 to 31 December 2016 and then another debit for depreciation expense from January 2016 up to the latest financial cut off period and of course the credit to accumulated depreciation.
