You didn't pay the tax, you had tax withheld, just like W-2 withholding that will be applied now to pay the tax.
The actual tax depends on your other income and margional tax bracket. If not enough tax was withheld, you will owe more.
The box 4 (or box 12 state) withholding will be added to all other withholding, such as W-2 withholding, and be shown on line 64 on the 1040 form to offset your overall tax liability.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
