I work full time and put in zero dependents on my W4. I also work 2 part time (adjunct professor) and put zero. I don't know if this is correct at all.
I just got divorced, so now single. (I changed my w4s in March after the divorce to single. But when I look at my numbers it shows me probably owing $3000. Why is that and what can I do to fix that. I definitely don't have $3000 to pay the IRS.
You can have additional taxes taken out of your paycheck. You can state that on your W4. You can use the IRS W4 calculator.
You can also pay estimated taxes:
Who Must Pay Estimated Tax
Individuals, including sole proprietors, partners, and S corporation shareholders, generally have to make estimated tax payments if they expect to owe tax of $1,000 or more when their return is filed.
Corporations generally have to make estimated tax payments if they expect to owe tax of $500 or more when their return is filed.
You may have to pay estimated tax for the current year if your tax was more than zero in the prior year. See the worksheet in Form 1040-ES, Estimated Tax for Individuals (PDF), or Form 1120-W, Estimated Tax for Corporations (PDF), for more details on who must pay estimated tax.