A business that is operated out of a business owner's residence and can be located in an established office within the residence. A small office/home office is considered a microenterprise since it typically has fewer than ten employees and is categorized one notch below a "small business." Traditionally, SOHOs are focused on white-collar jobs.

Prior to the proliferation of larger-scale businesses during the 19th century, most businesses would be categorized as SOHO. Entrepreneurs running this type of office include lawyers, consultants and freelancers who might not require a formal office to meet clients. Because a SOHO operates out of a home, some tax issues are treated differently by the Internal Revenue Service (IRS).