Why do I have a penalty?

[DoninGA]

Go to this IRS website for information on the Underpayment of Taxes penalty - https://www.irs.gov/payments/underpayment-of-estimated-tax-by-individuals-penalty

[JohnB5677]

You will have a penalty if you don't fulfill at least one of these IRS requirements.

• You paid 90% of the tax that you owe for the current year.  
• If the current taxes paid are equal to 100%, (110% for higher incomes) of your taxes owed the previous year.  
• The IRS also says you can probably avoid the penalty if the amount you owe is less than $1,000.

To avoid this, you should change your W-4 to take extra taxes from your paycheck, or pay estimated taxes. 

 For more information, see,  Avoid a tax penalty