Based on your financial expertise, provide your response or viewpoint on the given financial question or topic. The response format is open.

question regarding W4
Yes. W4 determines how much your employer will withhold from your wages. Leaving everything at default would mean that your salary is your only taxable income, and you only take default deductions. Your employee will calculate your tax withholding based on that. But, if your salary is >200k, I assume that you have other income (investment/capital gains, interest on your bank account), which you will have to pay taxes on. You're probably going to have some deductible expenses (business/partnership expenses, mortgage interest, donations, college funds etc) as well. So it is very likely, unless you're really not smart about money, that you have more to do with your taxes than just the employers' withholding.