A "sole proprietor" is a person who owns and operates a business by themselves. They have full control and responsibility for everything that happens in the business. Full definition
For the next 22 years, the Keenans worked as sole proprietors of Keenan Cabinetry, working exclusively for Canac. (thelitigator.ca)
It's been fascinating to discover how many people there are who believe in «anthropogenic global warming» and believe in climate science but really, strongly dislike Mann, his methods, and his promotion of himself as sole proprietor of Global Warming, Inc.. (steynonline.com)
More specifically, it's for sole proprietors who need a little help staying organized. (creditdonkey.com)