The point in time when an asset that can be depreciated is first placed in use. The date the asset is placed in service marks the beginning of the depreciation period. The date of purchase usually marks when an asset is placed in service, but not always.



Owners of depreciable assets should take note of the date that their depreciable assets are first placed in service, because they must record that date on their tax returns for depreciation calculations. The receipt for the good will effectively double as both proof of purchase and proof of date placed in service for the IRS in the event of an audit.