What is the consequence of underpayment of estimated taxes?

• A. No penalty if under $500 owed
• B. A flat fee regardless of the amount owed
• C. Interest and possibly a penalty if the taxpayer owes $1,000 or more when filing
• D. Immediate audit by the IRS

Answer: (C)

The consequence of underpayment of estimated taxes primarily involves interest and possibly a penalty if the taxpayer owes $1,000 or more when filing their return. This is based on the IRS guidelines that mandate individuals to pay a certain amount of their tax liability throughout the year, typically through withholding or estimated tax payments.

If a taxpayer's total liability exceeds this threshold and they have not made sufficient payments through estimated taxes, the IRS assesses both interest on the unpaid amount and a penalty, which serves as an incentive to ensure timely payment of taxes. The penalty can apply if at least 90% of the current year's tax or 100% of the previous year's tax is not paid through withholdings and estimated payments.

The other options do not reflect the full scope of consequences for underpayment. For example, a threshold of $500 or low flat fees do not account for the penalties imposed by the IRS under different circumstances, and an immediate audit is not a standard procedure for underpayment. The correct response accurately highlights significant financial implications of underpayment that taxpayers should be aware of to avoid penalties.