Enter your estimated taxes paid in the Taxes Paid group of the TurboTax Interview. (This group is also where you enter all state and local taxes you paid, 2015 tax refunds you applied to this year's returns, payments you made with extensions, and tax withholdings not reported to you on Forms W-2, 1099, or W-2G.

1. Click on the Federal Taxes tab
2. Got to Deductions & Credits
3. Scroll down to Estimates and Other Taxes Paid
4. Click start next to Estimates