I accidentally made two accounts. This is my second. I filed my 2016 taxes correctly with my old account (the one I used for 2015 Taxes). Can I delete this account?

Unfortunately, there is no way to delete an account. If you have not purchased anything on your account though, you may clear your information from your Account settings / Clear and start over and allow the account to go dormant. When you clear and start over, it WILL save your personal information, just not your tax information.

Here is an article to walk you through the steps of clearing and starting over, if applicable...

https://ttlc.intuit.com/replies/4248526

If you have made prior purchases on this account, you may contact customer service, and have them deactivate your account.

https://ttlc.intuit.com/replies/3300041