To be self-employed means one conducts business on their own, as a partner or owner, rather than working for employers. According to the instruction of IRS (on page 2), the person who will “carry on a trade or business as a sole proprietor or an independent contractor” is a self-employed person. The self-employed individual is generally required to submit an annual tax return and pay tax in advance quarterly by Form 1040 or Form 1040-SR.
See also: self-employment tax
[Last updated in March of 2022 by the Wex Definitions Team]