The S corporation tax return due date falls on quarterly dates throughout the year, but different forms are required for tax reporting purposes and those forms have varied due dates. 

S Corporation: A Brief Overview

An S corporation is a corporate structure known as a pass-through entity. The reporting of profits and losses from the corporation are the responsibility of the individual shareholders as is the paying of taxes. The corporation itself has a responsibility to file an information income tax return along with other tax forms that include payroll taxes for employees. 

S-Corporation Income Tax Return Deadline

The filing date for an S corporation is the 15th day of the third month that follows the end of the tax year. This date is usually March 15 but is subject to change in the event the due date falls on a holiday or weekend. Always make sure to check with the IRS to determine the due date. 

The corporation does not pay federal taxes, but it still has to prepare federal tax returns.  All financial activity has to be reported on Form 1120S, and a Schedule K-1 needs to be attached for each shareholder. The Schedule K-1 is a report of each shareholder's share of the taxable income of the business and allows them to report it on their personal returns. Shareholders who are paying tax on corporate income are subject to the personal income tax deadline of April 15 of every year. 

The completed Schedule K-1 is provided to all shareholders and shows that shareholder's portion of the company's:

  • Losses
  • Deductions
  • Credits

These are reported on the shareholder's personal income tax return. 

In the event the S corporation has employees it pays wages to, it is then responsible for the withholding of federal and state income taxes along with FICA taxes from their paychecks. The corporation has to file an IRS Form 941 every quarter to report the total amount it withholds from payroll and remits it to the IRS under each employee name.  Form 941 is due four times a year on:

  • January 31
  • April 30
  • July 31
  • October 31

Information reported on Form 941 includes:

  • Quarterly wages
  • Tips
  • Federal income tax withholdings
  • Social Security
  • Medicare
  • COBRA credit

Another required form is Form 940 which reports annual Federal Unemployment Taxes, known as FUTA. The purpose of Form 940 is to report the amount of wages the corporation has to pay unemployment taxes for. If the payments are more than $500 in any quarter, they become due and have to be paid by the last day of the month after the quarter. If the payments are under $500, they are due by January 31. In the event FUTA taxes were paid during a year in which the totals were more than $500, Form 940 is due in February. 

Making Federal Tax Payments

The IRS has a preference to receive all federal tax payments via its Electronic Federal Tax Payment System, also known as EFTPS. There are no fees for filing through EFTPS. If a corporation does not wish to use EFTPS, it can make a payment using a same-day wire transfer from its bank or financial institution. An alternative option is to have a payroll service or tax professional make the payment on behalf of the corporation. Keep in mind that a service may charge fees for the filing service. 

All federal and state tax notices have a published deadline that state what date the taxpayer has to respond by. Always respond in a prompt manner and consult with a tax professional if you need assistance with how to proceed. 

Late Filing Penalties

If an S corporation fails to file Form 1120S by the due date, whether normal or extended, the IRS imposes a minimum penalty of $195 for each month, whether it's a whole or partial month, and multiplies the penalty by the number of shareholders. 

In the event the corporation files its Form 941 after the deadline without filing an extension and has an unpaid tax balance, the IRS may assess a 5-percent penalty for each whole or partial month the tax is late. 

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