Business income includes income from any activity you do for profit. For example, income from a service business is business income. However, business income does not include employment income.
Include all your income when you calculate it for tax purposes. If you do not report all your income, you may be subject to a penalty of 10% of the amount your did not report after your first omission.
A different penalty may apply if you knowingly or under circumstances amounting to gross negligence participate in making a false statement or an omission on your income tax return. This penalty is 50% of the tax attributable to the omission or the false statement (minimum $100).