Most companies will have (and should have) a clause saying that unless its totally unrelated to the company's business, then they own it. If you quit a job and

Most companies will have (and should have) a clause saying that unless its totally unrelated to the company's business, then they own it. If you quit a job and start a company that is unrelated to your ex-employers business then you are in the clear provided you can demonstrate that you didn't start generating ideas until you after you left. If you quit a job and start something that competes, then you need to take at least 6 months off and go travel the world. Otherwise they can sue you, and probably win. Getting sued at this stage is probably enough to destroy your business. Getting sued by someone who is probably going to win is guaranteed to destroy your business. Unless you can demonstrate the 6 months off, very compellingly, you will get sued when you launch at the latest. Your source code and the equipment its on will be sought as evidence. IANAL, but this was the advice I was given by someone who would know. One thing you can do is have an attachment to the contract that lists all IP that you already own, and further, get it agreed that this IP is unrelated to the company's business so you can keep working on it.