Among forms of business organization, lawyers probably like partnerships least, and they recommend them to clients only rarely. Still, thousands of partnerships exist in New Mexico, despite what attorneys think of them.
Partnerships are easy to create, which is why there are so many.
A partnership is simply two or more people in business to make a profit. You don't need legal documents. Undocumented deals always carry the risk that months or years later, participants will remember details differently. Sometimes the difference is so great that it's hard to believe that people are talking about the same thing. One big job of business lawyers is to write all this down at the beginning to avoid misunderstandings later.