1. Get in touch with your co-founder. It's just not practical to split up any other way. Time is not critical, if it takes 2 weeks, so be it. 2. Once you talk,

1. Get in touch with your co-founder. It's just not practical to split up any other way. Time is not critical, if it takes 2 weeks, so be it. 2. Once you talk, make sure your co-founder agrees with leaving without creating a mess. The 50/50 split is a potential issue here. Technically, you may not have the power to remove your co-founder. Did you have vesting in place? Did you incorporate with a decent lawyer? If I understand your train of thought, you are thinking of leaving the company, ignore it and continue working on the idea. If you do so and later become successful, definitely expect a big lawsuit from your old co-founder claiming his share... Not to mention the fact that investors will not like hearing about such a liability. If at all possible, work out something with your co-founder.