• The first element of cost (generally the purchase price and any transportation and installation costs).
• Any second elements of cost (generally amounts paid on improving or upgrading the asset ready for use).
• The opening adjustable value for the income years you hold the asset and are claiming a deduction.
• Any adjustments made to the cost or adjustable value and evidence to support this.
• 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 years in which you hold it.
• 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.
• Diary or other records showing the taxable purpose portion of the asset.