S corporations that are required to file 10 or more returns in a calendar year (calculated by aggregating all returns of any type) are required to e-file their Forms 1120-S, effective for returns required to be filed on or after January 1, 2024. Find details on the final e-file regulations. For more e-file information, see E-file for business and self-employed taxpayers.

S corporations are corporations that elect to pass corporate income, losses, deductions, and credits through to their shareholders for federal tax purposes. Shareholders of S corporations report the flow-through of income and losses on their personal tax returns and are assessed tax at their individual income tax rates. This allows S corporations to avoid double taxation on the corporate income. S corporations are responsible for tax on certain built-in gains and passive income at the entity level.

In order to become an S corporation, the corporation must submit Form 2553, Election by a Small Business Corporation signed by all the shareholders. See the Instructions for Form 2553 PDF for all required information and to determine where to file the form.