Here is a question that sounds technical and is actually about fairness: you and your cofounder have been building for ten months, and now you are incorporating. Your vesting starts at four years. Four years from when?
If the answer is "from incorporation", the founder who quit her job ten months ago just watched those ten months vanish from her schedule. On paper, she has earned nothing yet. If she left three months after incorporation, a standard one-year cliff would hand her zero equity for thirteen months of real work. Nobody sitting at that table believes that outcome is fair. The document says it anyway.
This is why the honest answer is usually yes: vesting should recognize the work that predates the company. The clean way to do it is vesting credit, sometimes called backdated vesting. The schedule still runs four years, but its start date is set at the moment the real commitment began, not the day the lawyer filed the paperwork. Ten months of credit means ten months already earned on day one of the company. The cliff, if you keep one, has often already been served by the time you incorporate, which matches the reality: the risky, unpaid, uncertain period is precisely the one you just survived together.
Two warnings from the disputes side. First, the start date must be a fact, not a feeling. "When we got serious" is not a date; it is a future argument. Pick something verifiable: the day someone went full time, the first commit on the shared repo, the date on your founder agreement. Write the date and write why. Second, credit must be symmetric in method, not necessarily in amount. If one founder started six months before the other, their credits differ, and that is fine, because the rule that produced them is the same. What breaks teams is not different numbers. It is numbers nobody can explain a year later.
One more reason to settle this before incorporation rather than after: leverage moves. Before the company exists, you are two people agreeing on what is fair. After incorporation, with shares issued and roles set, the same conversation becomes a negotiation, and whoever benefits from the default schedule has quietly gained the upper hand. The founder agreement you sign now can fix the vesting start date in writing, so the incorporation documents inherit the decision instead of reopening it.
Your startup existed before your company did. Your vesting should know that.