Self-employment is the state of working for oneself rather than an employer. Tax authorities will generally view a person as self-employed if the person chooses to be recognised as such or if the person is generating income for which a tax return needs to be filed. In the real world, the critical issue for tax authorities is not whether a person is engaged in business activity (called trading even when referring to the provision of a service) but whether the activity is profitable and therefore potentially taxable. In other words, the trading is likely to be ignored if there is no profit, so occasional and hobby- or enthusiast-based economic activity is generally ignored by tax authorities. Self-employed people are usually classified as a sole proprietor (or sole trader), independent contractor, or as a member of a partnership.

Self-employed people generally find their own work rather than being provided with work by an employer and instead earn income from a profession, a trade, or a business that they operate. In some countries, such as the United States and the United Kingdom, the authorities are placing more emphasis on clarifying whether an individual is self-employed or engaged in disguised employment, in other words pretending to be in a contractual intra-business relationship to hide what is in fact an employer-employee relationship.

Self-employment provides work primarily for the founder of the business. The term entrepreneurship refers to all new businesses, including self-employment and businesses that never intend to grow big or become registered, but the term startup refers to new businesses that intend to provide work and income for more than the founders and intend to have employees and grow large.

In summary:

Although the common perception is that self-employment is concentrated in a few service sector industries, like salespeople and insurance agents, research by the Small Business Administration has shown that self-employment occurs across a wide segment of the U.S. economy. Furthermore, industries that are not commonly associated as a natural fit for self-employment, such as manufacturing, have in fact been shown to have a large proportion of self-employed individuals and home-based businesses.

In the United States, any person is considered self-employed for tax purposes if that person is running a business as a sole proprietorship, independent contractor, as a member of a partnership, or as a member of a limited liability company that does not elect to be treated as a corporation. In addition to income taxes, these individuals must pay Social Security and Medicare taxes in the form of a SECA (Self-Employment Contributions Act) tax.

In 2016, the median income for individuals self-employed at their own incorporated businesses was $50,347. For individuals self-employed at their own unincorporated firms, this figure was $23,060.

Self-employment is relatively common among new immigrants and ethnic minorities in the United States. In the United States, immigrants tend to have higher rates of self-employment than native-born Americans regardless of race or ethnicity. But, self-employment in the United States is unevenly distributed across racial/ethnic lines. Immigrants and their children who self-identify as White have the highest probability of self-employment in lucrative industries such as professional services and finance. In contrast, racial and ethnic minorities are less likely than native-born Whites to be self-employed, with the exception of Asian immigrants who have a high rates of self-employment in low prestige industries such as retail trade and personal services. Much like the regular labor market, self-employment in the United States is stratified across racial lines. In general, self-employment is more common among immigrants than their second-generation children born in the United States. However, the second-generation children of Asian immigrants may continue to seek self-employment in a variety of industries and occupations.