Under Missouri Law, a general partnership, unlike a limited liability or corporation, does not necessarily require that the owner(s) file an organization or incorporation document with the Secretary of State. Rather, Missouri law will recognize the existence of a general partnership when 1) two or more people 2) carry on a business as co-owners with 3) the intent to make a profit. Even if it is unintentional, a Court will determine that such a relationship is a general partnership.
Although general partnerships are quite easy to start, they have some major downsides. The biggest downside is that there is no limitation of liability. As such, the owners in a general partnership will be held personally liable for the liabilities of the business. Thus, while it may be simpler to avoid the legalese and simply go out with your business partners and plant your flag, it is infinitely better to draft up legal documents which clearly articulate the role of business partners and flesh out the function and nature of the business enterprise.