• The first element of cost (generally the purchase price).
• Any second elements of cost (generally the expense of getting the asset ready for use). 
• The opening adjustable value for the income year. 
• Any adjustments made to the cost or adjustable value. 
• The date you started holding the asset and its start time. 
• The rate or effective life used to work out the decline in value. 
• The method used to work out the decline in value. 
• The amount of your deduction for the decline in value and any reduction for use of the asset for a non-taxable purpose. 
• The adjustable value at the end of the income year. 
• Any recoupment of cost you have included in assessable income. 
• If a balancing adjustment event occurs for the asset during the year: 
  • the date of the balancing adjustment event 
  • termination value 
  • adjustable value at that time 
  • the balancing adjustment amount 
  • any reduction of the balancing adjustment amount 
  • details of any rollover or balancing adjustment relief. 

You must also keep: 

• details of how you worked out the effective life of a depreciating asset where you have not adopted the effective life determined by the Commissioner of Taxation 
• if you have recalculated the effective life of an asset 
  • the date of the recalculation 
  • the recalculated effective life 
  • the reason for the recalculation 
  • details of how you worked out the recalculated effective life 
• information you used to work out your claim, such as the amount of any private use of the assets.

• Original documents such as suppliers’ invoices and receipts for expenditure on the depreciating asset. 
• Depreciation schedule. 
• Sale contract.