All businesses except partnerships must file an annual income tax return and must pay tax on income as it is earned or received during the year; this includes attorneys entitled to a portion of any damages award or settlement amount. If you are a Sole proprietor then you may be liable for: 1) income tax; 2) self-employment tax; 3) estimated tax; 4) employment taxes; and 5) excise taxes. If you are a partnership then you may be liable for: 1) annual return of income; 2) employment taxes; and 3) excise taxes. If you are a partner in a partnership (individual) then you may be liable for: 1) income tax; 2) self-employment tax; and 3) estimated tax. If you are a corporation or S corporation then you may be liable for: 1) income tax; 2) estimated tax; 3) employment taxes; and 4) excise taxes. If you are a S corporation shareholder then you may be liable for: 1) income tax; and 2) estimated tax.