Legal Question in Business Law in California

No, but you are fools if you don't.

Without a proper and detailed agreement, how do you plan on proving what the 'deal' is when a dispute arises?

There is no requirement that partnerships have to have a written agreement to be formed, but it is very very very important to have one. Again, I highly advise that you enter into an written agreement for your partnership.

Best,

Jim Betinol

It depends upon what you mean by "agreement."

General partnerships can be formed by written agreement, oral agreement, or by an implied agreement, e.g., conduct of the parties showing that they are operating as general partners even though they haven't formed an "actual" agreement in words. See Corporations Code section 16101(10).

Mr. Whipple is correct. In fact the default business form if owned by more than one person, and if you do not have a formal agreement and related filings to be something else, is that you are automatically a partnership. If you don't have an agreement, the Corporations Code provisions on partnerships become your partnership agreement by default once you agree to conduct business together, or create an implied agreement to do so by going out and doing business together.

You have gotten great advice, get an attorney and set up the agreements or in the end you will get what you paid for.