Only on new shares purchased. All shares purchased are based on each and every transaction date. Your accountant should easily be able to handle for you. I use Turbo Tax in the United States. Not sure about Australia and/or what taxes may owe to U.S. (if any). It's great. Can import both Schwab & TDA tax documents. Calculates everything for me. Can set-up stock transactions and records a number of ways: >> FIFO (First-in, first-out). >> Cost Basis >> Tax Optimization >> Etc. No need to worry, Scruff