[Aurornis]

All companies are registered. They have to be registered to be legal entities, have bank accounts, and comply with tax laws.

Private companies don’t need to publicly divulge a lot, though. It’s between the company and their investors. It’s only once a company wants to trade publicly that they have to provide a lot of public details and financials.

[trollbridge]

You don’t have to register a general partnership as long as it has one of the partners’ last name in the partnership name, although I guess you have to get an EIN to file partnership taxes.

A sole proprietorship doesn’t have to register anything ever at all.

[SoftTalker]

Although in most cases it’s sensible to register a single member LLC instead of operating as a sole proprietor. That way the LLC can be separate from the owner’s personal assets.

[Aurornis]

Great point. I suppose I should have said all companies like this (the corporation Bezos is involved with) are registered entities.

There are ways to do business activities yourself without registering an official business, though it’s generally discouraged because forming an LLC is so cheap and easy and provides some protections and benefits.