I've decided to use a CPA this year to file my taxes. I used turbotax to go through the motions, but for a little more money I'd rather have a pro deal with this. Understandably he's over capacity so I'll be filing an extension and he'll get to me in early May.
For lines 4 and 5 on form 4868, what number is used? Federal taxes, social security?
Here's the form: https://www.irs.gov/pub/irs-pdf/f4868.pdf
If you've already used TurboTax on your 2015 taxes, you can use the numbers TurboTax gave you as your reasonable estimate.
Line 4 is your estimate of total tax liability for 2015. This would be line 63 of form 1040. This is Federal income tax only, not Social Security tax.
Line 5 is the total of tax payments you made last year. You should be able to read this off your W-2 forms, Box 2. It corresponds to line 74 on the 1040.
Line 6 is the difference between lines 4 and 5. You can't claim a refund on the extension, so if line 5 is more than line 4, enter 0. Otherwise, subtract line 5 from line 4, and enter it in line 6. This is the amount you should send in with the form to minimize any penalty due with your taxes later.
The TurboTax software can generate this extension form automatically, I believe.
Also, don't forget to give a copy of this extension form to your tax preparer. He will need to know the amount you sent in.
