A capital gain will occur when you have disposed of an asset such as property, shares in a company, units in a trust or crypto. If you have sold any of these, then we are likely to need purchase price, purchase date, purchase costs, holding/other costs, sale costs, sale date and sale amount as a minimum. If you are unsure what you need to provide us, please provide as much information/commentary as possible and we will request anything additionally when we complete your return.