A sole proprietorship is a business owned by an individual or husband and wife, and which is not a business entity (like an LLC or corporation). Sole proprietorships often use an assumed business name (“ABN”) which is a name used to identify themselves to the public (like “Bill’s Bakery” or “A&M Corner Store” etc). A sole proprietorship is an extremely poor form under which to do business because it provides its owners with no legal protection against liability. Essentially the business is an alter-ego of the owner(s) and therefore the owner(s) would be responsible for all of the business’ debts and liabilities. What this means in practical terms is that if anyone successfully sued a sole proprietorship, then they could seize the owner(s)’ personal assets (their house, cars, investments etc) to satisfy the judgment. This is in contrast to operating as a business entity where, if it was operated properly, creditors could not access the personal assets of its owners (except under certain circumstances like fraud, or criminal/quasi-criminal conduct).