Your employer reports your bonus income on your year-end W-2 tax form and is part of your gross income for tax purposes. However, your work may withhold a different tax percentage than your regular pay. The tax software will calculate your total tax liability after compiling your taxable income, total withholding, tax deductions, and tax credits when you file your tax return. If you apply for financing, the lender may request that you separate your regular pay from any bonuses or overtime you earn to establish your base annual salary accurately.