Are you required to make estimated tax payments?
An individual who receives income not subject to withholding and whose liability exceeds $1,000 is subject to remittance otherwise they are facing sizable, nondeductible penalties.
The IRS imposes penalties for failing to make estimated payments and also for failure to remit those installments on time.
Guess what?!? If the prior three quarters were underpaid and the balance was paid with the final installment, chances are the IRS will not forgive the penalties of underpayments.