Monchilla automatically calculates the correct federal income tax withholding on all paychecks, but if you want to manually specify the amount of federal income tax withholding on a paycheck it is easy.
1. Click Payroll>>Paychecks, select the paycheck you want to edit and click Edit Item.
2. Select the Federal Income Tax Withholding line and click Edit Item.
3. Change the Type from Federal Income Tax Withholding to Fixed Amount and change the Value to the amount of Federal Income Tax you want withheld on this paycheck and click Save.
4. Click Save again.
5. You're done.