Once a TurboTax account is created, it cannot be deleted. You can simply abandon it.
If you'd like to clear any data that you may have entered into the program, as long as you haven't submitted payment, deducted the TurboTax fee from your refund, or registered, you can use the "Clear and Start Over" feature. See instructions below.https://ttlc.intuit.com/replies/4248526