I used my email and account for my son's tax return previously, can I simply change the personal details and enter my own tax return this year?

posted

No. You need to set up your own online account.

Online is only good for one return per account. But you can use the same email address for 5 accounts. So don't use your account or you will overwrite your return.

The Desktop program can do unlimited returns and efile 5 federal for free. You can buy the Desktop Download program here,
https://turbotax.intuit.com/personal-taxes/cd-download