Once again, the IRS recommends filling out these lines on the W-4 form associated with the highest-paying job; on your other W-4 forms, leave those two lines blank.

To do so, you’ll need to fill out Form W-4V, Voluntary Withholding Request, and indicate how much you want withheld.

The W-4 is the form you fill out when starting a new job to determine how much federal income tax is withheld from your paycheck. While the default W-4 settings will work for many people, you may ...