How can I close my online turbotax account?

[xmasbaby0]

You do not have to "close" it.  If you have decided not to use the TT account, just clear it out and abandon it.

https://ttlc.intuit.com/questions/2586254-how-do-i-clear-and-start-over

[kipfenberg]

Thank you, but I am unable to clear it.  The account automatically fills in again what I delete.  I have nevery prepared a return on online, and have not been a customer of TurboTax for some years now.  I just don't like having that account out there with personal information, knowing I will never use it again!

[xmasbaby0]

Oh--you did not mean you wanted to clear out a tax return--you want to deactivate your TT account?

Per Critter:

There is a new service being offered…it  is the ability to deactivate the account .... Contact support for a case number if you really want to put forth the effort to use that feature ....

Use the following TurboTax website to contact TurboTax customer service/support.   

Submit your question/problem during business hours and then use the option for Call.  
There will be some personal information gathered so a case can be created for you.  A phone number will then be provided, specific to your case, to speak directly with a TurboTax agent.
https://support.turbotax.intuit.com/contact/
Note:  The Call option will not be available when TurboTax Support is closed.

https://ttlc.intuit.com/questions/2930711-account-deactivation-verify-your-identity