Do I need an operating agreement if it's just my co-founder and me?

This question comes up constantly from two-person founding teams, usually framed the same way: we trust each other completely, we're splitting everything 50/50, do we really need to formalize this in writing? Yes. Not because the trust isn't real, but because an operating agreement isn't really about trust. It's about the conversation you're forced to have before there's money or tension on the table.

Without an operating agreement, your LLC falls back on default state rules, and those defaults were not written with your specific situation in mind. They govern who can bind the company, how profits get distributed, what happens if one of you wants out, and what happens if one of you stops contributing. None of those defaults are likely to match what you and your co-founder would actually choose if you sat down and thought it through, and you won't find out they don't match until you're in a disagreement and reaching for the document that isn't there.

The real value of the operating agreement is what it forces you to decide now, while you still agree on everything: What happens if one founder wants to leave in year two? Does their equity vest, or do they walk away with the full stake day one? What happens if one of you stops showing up, keeps their ownership, and the other is doing all the work? Who has authority to sign contracts or spend above a certain amount without the other's sign-off? What happens if you deadlock on a decision and can't agree?

Every one of those questions is easy to answer calmly before there's a dispute. None of them are easy to answer in the middle of one. That's the actual argument for doing this early, not "trust each other" versus "get it in writing" as if those are opposites. The agreement is what your trust looks like once it's written down clearly enough that neither of you has to rely on memory or goodwill six months from now.

The practical version: even a straightforward operating agreement for a two-person LLC should cover vesting or buyback terms if someone leaves, decision-making authority and what requires both signatures, and a mechanism for resolving a deadlock. Get that in place before the business has anything worth arguing over, not after.