An offering circular is a document issued by companies or other entities that are offering newly issued securities to the public in accordance with U.S. federal law and Securities and Exchange Commission (SEC) regulations. It serves as a regulatory disclosure document that provides potential buyers with essential information about the security offering.

In the United States, an offering circular must be filed with the SEC in order for a company to make an offering not limited to sophisticated investors such as qualified institutional buyers, accredited investors, or qualified purchasers. The offering circular includes basic information about the issuer, type of security being offered, and intended use of the proceeds.

Essential information contained in an offering circular includes the issuer’s name, address and other contact information, the duration of the offering, the business operations and history of the company, the names of directors, the terms and conditions of the security being offered, the structure of the offering, the reason intended to raise capital, the risks associated with the offering, and the use of proceeds. The offering circular also includes key information such as the offering's registration statement, associate documents, financial statements, and other relevant documents such as agreements associated with the offering and number of shares being offered.

The terms of the offering must also include an offer of rescission to investors who purchase securities and then wish to terminate their purchase within a certain time frame. The offering circular must also include the issuer's audited financial statements and applicable reports made to the SEC.

The offering circular should be read and fully understood before any individual or entity purchases a security. It is important to note that the SEC does not approve offering circulars and will not comment on them.

In conclusion, an offering circular is an important document that provides investors with essential information about the offering, such as the issuer, security type, terms and conditions, use of proceeds, and risks, which are all necessary for potential investors to make an informed decision.