"Federal Estimated Tax Payments" allows you to record payments made to the IRS on income that may not be subject to withholding.
If you are filing as a sole proprietor, partner, S Corporation shareholder and/or self-employed, you will generally need to make estimated tax payments if you expect to owe tax of $1,000 or more at the time you file your return. Generally, estimated payments are made quarterly.
You can also elect to make estimated payments if the amount of income tax being withheld from your salary, pension, or other income is not enough.