I think the advice you've gotten so far is poor. There's only one thing you should do at this point: talk to a lawyer. Any other action you take is foolish. It

I think the advice you've gotten so far is poor. There's only one thing you should do at this point: talk to a lawyer. Any other action you take is foolish. It depends on where you live, and it depends on what your contract says (you did sign something, right?). For what it's worth, the entire scale is heavily slanted in their favor. They could simply give you a new contract to sign that prohibits that specific project and fire you if you refuse to sign it (yes, that's 100% true, in contract law maintaning your job is a form of Consideration(1) ). Typically side projects are documented and signed off on by the company at which point you are in the clear. You are far better off assuming that anything that isn't explicitly stated will end up working in their favor. (1) https://en.wikipedia.org/wiki/Consideration https://en.wikipedia.org/wiki/Consideration