> If you didn't incorporate yet, then you owe each other nothing.
Anything that does business is a company (incorporation is needed to form a corporation, which is a specific kind of company; the term is often also used for forming a LLC, another particular kind of company); if two people have joined together with the intent of making a for-profit enterprise but with no formal agreement, it is a partnership.
See, e.g., the first couple paragraphs of this piece, even though the whole piece is focussed on unincorporated nonprofit associations: http://www.nolo.com/legal-encyclopedia/what-an-unincorporate...
And, even when informally formed, partnerships do have consequences while they exist and steps that need to occur to finally end them. Particularly, getting rid of a partner in such a situation generally means dissolving the partnership. Here's one guide, but definitely not complete info for all scenarios: http://smallbusiness.chron.com/dissolve-informal-partnership...