I paid $9600 (annual tot) extra fed tax withholding via a W4 form. Do I record this amt as "Add Payment" on Turbotax page "How much did you pay in fed estimated taxes"?

[DoninGA]

The additional taxes you paid through payroll withholding be included in box 2 of the W-2.

[xmasbaby0]

"...via W-4..." means you had your employer withhold tax from your paycheck.  You indicated to the employer how much tax to withhold from your paychecks when you gave the W-4 to the employer.  The amount the employer withheld for federal tax is in box 2 of your W-2.  You do not enter that amount anywhere else---just enter it from your W-2.  

[VolvoGirl]

No, estimated taxes are only paid on a 1040ES quarterly during the year by you directly not a W4.   The W4 extra amount will be included on your W2 box 2.  It isn't broken out.  Only enter W2 box 2.    Your total W2 withholding will show up on 1040 line 25a.