When you acquire a capital gains tax (CGT) asset, you need to start keeping accurate records as there may be a long period of time between acquiring and disposing of the asset. Without these records, you may end up paying more tax than necessary. 

How long you need to keep capital gains tax (CGT) records 

You need to keep CGT records for 5 years after you sell or dispose of an asset, unless you keep an asset register. 

Keeping an asset register may allow you to discard some records that you might otherwise need to keep for a long time. Once details have been entered into the register and the register has been certified by an approved person (such as a registered tax agent), you only have to keep the documents for 5 years from the date the register is certified. 

For a CGT event that resulted in a capital loss which you've offset against a capital gain in a later year, you need to keep records from the year of the offset, for a further: 

• 2 years for individuals or small businesses 
• 4 years for other taxpayers.