It applies to any time and all accounts as George stated. If you sell at a loss, you can't buy back within 30 days in any of your accounts or you kick in superficial tax loss. You don't lose the tax loss forever but do for that year unless you completely sell out the position before the end of that year. In a year that you completely sell out the position, you can then claim the loss all the way back to the superficial loss which has then become not superficial. You could sell right now and if you bought back before 30 days, it would be superficial at that point for 2020. If then, you sold your complete position in September 2020, it would then become not superficial as long as you didn't buy back again within 30 days so could all then be claimed in 2020. If you instead didn't sell the complete position until 2021 and then didn't buy back in for 30 days, it would all become not superficial and be able to claim in 2021. Koo - it was designed to stop short term year-end tax loss selling and that is why you can make it elligible again when you do it over a longer term.