If the de minimis and the safe harbor exceptions do not apply, use IRS Form 2210 to compute the underpayment penalty using the annualized method. 

The worksheet annualizes the tax at the end of each period based on actual income, deductions, and other items relating to events that occurred since the beginning of the tax year through the end of the period. If this exception is used, Form 2210 must be attached to the tax return.