TurboTax accounts cannot be deleted. You can simply abandon your account and allow it to go dormant if you will not be using it in the future, although if you have used online TT for past year returns, you should keep a record of how to access your account. Returns are saved in your online account for seven years--the same amount of time as the IRS saves them. Nothing is ever "downloaded" to your account unless you initiate that by importing data.