Investment Read Time: 3 min Key Money Moments: 4 Times You Should Talk to a Pro Share | Related Content You May Need to Make Estimated Tax Payments If… Have income that isn’t subject to tax withholding? Or insufficient withholdings? You may have to pay estimated taxes. Four Really Good Reasons to Invest There are four very good reasons to start investing. Do you know what they are? Federal Income Tax Use this calculator to estimate your income tax liability along with average and marginal tax rates.