TurboTax accounts can never be merged or combined. If you are using your own account with your own user ID no one else can access your new account.
However----if your ex-spouse has access to the old account that you used for joint returns---your SSN is there and you can do nothing about that. Your ex has the right to look at any joint return that her name was signed to.
If the two of you are disputing who can claim the children----the IRS cares who the children lived with. The custodial parent is the one who the children lived with for at least 183 nights of the tax year.
If the non-custodial parent files first and their return is accepted, then any other tax return using the children's Social Security numbers will be rejected. If that happens, the return claiming the children must be filed by mail---and then the IRS sorts out who could claim the children,
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
