How much does having a written operating agreement change my case?

Substantially, and in ways that touch nearly every aspect of how your case would actually proceed. A written operating agreement might contain a mandatory arbitration clause, contractually requiring your dispute to be resolved through private arbitration rather than the public court system entirely. It might also specify a buyout formula, a predetermined method for calculating the price of a departing or aggrieved partner's ownership interest, which could significantly simplify or complicate your damages calculation depending on its specific terms, or a fee-shifting provision governing who pays legal costs.

If no written agreement exists between you and your partner, California's default partnership statutes, found in the Corporations Code as the Revised Uniform Partnership Act, automatically supply the governing terms instead. These default rules commonly assume equal profit sharing between partners regardless of how much capital or effort each partner actually contributed, which can work distinctly against a partner who contributed disproportionately more, absent some other way of proving a different arrangement was actually agreed to through conduct or communications.