Majority of business owners don't have payroll. For them, taxes must be paid every quarter or penalties and interest will follow. A business owners must pay estimated income tax if they expect to owe more than $ 1000. For more information refer to IRS publication 505, Tax withholding and Estimated Tax.
Payment dates for estimated tax are :

• First Quarter: April 15


• Second Quarter: June 15


• Third Quarter: September 15


• Fourth Quarter: January 15