I completed my taxes for 2015 recently and submitted $4597 along with my filing for federal taxes I owed. I have a new bill from the IRS for additional payments

[boxsteron]

The payments are for penalties and interest.  How do I know those are correct and why didn't Turbotax warn me about those?  Isn't Turbotax supposed to take care of all those issues?  With what I pay you for it, it absolutely should

[VolvoGirl · Accepted solution]

If you paid a tax due after April 18 there is interest and penalties.  Turbo Tax can only estimate the amount on 1040 line 79.  It's based on exactly when the IRS gets your payment and Turbo Tax wouldn't know the exact date the IRS will get your payment..  It's common for the IRS to bill you for more.

[VolvoGirl]

Did you get an extension?  An extension is only to file the return.  Any tax due was still due back on April 18.  You were suppose to send in a payment with the extension with an estimate of what you might owe.  Here is a FAQ I found so far,
<a rel="nofollow" target="_blank" href="https://ttlc.intuit.com/questions/2550071-does-an-extension-give-me-more-time-to-pay-my-taxes">https...>