In any business entity, the type of business determines the income tax return form to be filed. In other words, the business structure determines the legal and tax considerations. S Corporation is one of the most common forms of business structure with a limited number of shareholders that is treated as a partnership for tax purposes.

An S Corporation is a type of corporation that is taxed under subchapter S of the Internal Revenue Code. Small business proprietors commonly use the S Corporations structure. There are no corporate taxes. Profits and losses directly pass to stockholders. S Corporations allow pass-through tax treatment and thus avoid double taxation associated with standard C corporations. The percentage of ownership determines the percentage of pass-through income. An S Corporation can have only one class of stock. It can have a single owner and cannot have associated self-employment taxes. The ownership of an S Corporation is restricted to no more than 75 shareholders. The shareholders must be citizens of the Unites States. In order to be treated as an S Corporation, all shareholders must sign and file IRS Form 2553.

For federal taxation purposes, the S Corporation files its annual return using Form 1120S. The 1120S is an informational return. It simply informs the federal tax authorities the amount of net profit or loss made by the S Corporation. There is no tax payment or refund associated with the 1120S tax return, as the S Corporation does not have independent tax status. The S Corporation is managed and run by its directors and officers. The directors are appointed by shareholders and are responsible for corporate governance and overall management of the corporation. The directors in turn appoint officers for the day-to-day management and operations. In small businesses, one person can be the only shareholder, the only director, and the only officer. In order to qualify as an S Corporation for the 2006 tax year, the corporation must file the IRS Form 2553 by March 15, 2006.