An S corporation, for United States federal income tax purposes, is a corporation that makes a valid election to be taxed under Subchapter S of Chapter 1 of the Internal Revenue Code.

In general, S Corporations do not pay any federal income taxes. Instead, the corporation's income or losses are divided among and passed through to its shareholders. The shareholders must then report the income or loss on their own individual income tax returns. This concept is called single taxation; if the corporation is taxed as a C Corporation, it will face double taxation, meaning both the corporation's profits, and the shareholders' dividends, will be taxed.

An overview of S corporations

S corporation status provides many of the benefits of partnership taxation and at the same time gives the owners limited liability protection from creditors. The S corporation rules are contained in Subchapter S of Chapter 1 of the Internal Revenue Code (sections 1361 through 1379). S status combines the legal environment of C corporations with U.S. federal income taxation similar to that of partnerships.

Like a C corporation, an S corporation is generally a corporation under the law of the state in which the entity is organized. S corporations are separate legal entities from their shareholders and, under state laws, generally provide their shareholders with the same liability protection afforded to the shareholders of C corporations. For Federal income tax purposes, however, taxation of S corporations resembles that of partnerships. As with partnerships, the income, deductions, and tax credits of an S corporation flow through to shareholders annually, regardless of whether distributions are made. Thus, income is taxed at the shareholder level and not at the corporate level. Payments to S shareholders by the corporation are distributed tax-free to the extent that the distributed earnings were not previously taxed. Also, certain corporate penalty taxes (e.g., accumulated earnings tax, personal holding company tax) and the alternative minimum tax do not apply to an S corporation.

Unlike a C corporation, an S corporation is not eligible for a dividends received deduction.

Unlike a C corporation, an S corporation is not subject to the 10 percent of taxable income limitation applicable to charitable contribution deductions.

Qualification for S corporation status

In order to make an election to be treated as an S corporation, the following requirements must be met:

• Must be an eligible entity (a domestic corporation, or a limited liability company.
• Must have only one class of stock.
• Must not have more than 100 shareholders.
• Spouses are automatically treated as a single shareholder. Families, defined as individuals descended from a common ancestor, plus spouses and former spouses of either the common ancestor or anyone lineally descended from that person, are considered a single shareholder as long as any family member elects such treatment.

If a corporation meets the foregoing requirements and wishes to be taxed under Subchapter S, its shareholders may file Form 2553: "Election by a Small Business Corporation" with the Internal Revenue Service (IRS). The Form 2553 must be signed by all of the corporation's shareholders. If a shareholder resides in a community property state, the shareholder's spouse generally must also sign the 2553.

The S corporation election must typically be made by the fifteenth day of the third month of the tax year for which the election is intended to be effective, or at any time during the year immediately preceding the tax year. Congress has directed the IRS to show leniency with regard to late S elections. Accordingly, often, the IRS will accept a late S election.

Some states such as New York and New Jersey require a separate state-level S election in order for the corporation to be treated, for state tax purposes, as an S corporation.

If a corporation that has elected to be treated as an S corporation ceases to meet the requirements (for example, if as a result of stock transfers, the number of shareholders exceeds 100 or an ineligible shareholder such as a nonresident alien acquires a share), the corporation will lose its S corporation status and revert to being a regular C corporation.

Furthermore, if more than 25% of a S-corporation's gross receipts consists of passive income for three consecutive years when the corporation has accumulated earnings and profits, the S corporation will automatically lose its subchapter S status and revert to being a regular C corporation.

Taxation issues

The S election affects the treatment of the corporation for Federal income tax purposes. The election does not change the requirements for that corporation for other Federal taxes such as FICA and Federal unemployment taxes.

FICA

As is the case for any other corporation, the FICA tax is imposed only with respect to employee wages and not on distributive shares of shareholders. Although FICA tax is not owed on distributive shares, the IRS and equivalent state revenue agencies may recategorize distributions paid to shareholder-employees as wages if shareholder-employees are not paid a reasonable wage for the services they perform in their positions within the company.

Distributions

Actual distributions of funds, as opposed to distributive shares, typically have no effect on shareholder tax liability. The term "pass through" refers not to assets distributed by the corporation to the shareholder, but instead to the portion of the corporation's income, losses, deductions or credits that are reported to the shareholder on Schedule K-1 and are shown by the shareholder on his or her own income tax return. However, a distribution to a shareholder that is in excess of the shareholder's basis in his or her stock is taxed to the shareholder as capital gain.

Conversion from C Corporation

S corporations that have previously been may also, in certain circumstances, pay income taxes on untaxed profits that were generated when the corporation operated as a C corporation. This is very common with uncollected accounts receivable or appreciated real estate.