The Facts About Income Tax Millions faithfully file their 1040 forms each April. But some things about federal income taxes may surprise you. Share | Related Content Tax Freedom Day Assess how many days you'll work to pay your federal tax liability. How to Appeal Your Property Taxes For homeowners who think their property taxes are too high, there are ways to appeal. Comparing Investments This calculator compares the net gain of a taxable investment versus a tax-favored one.