If you incorporate, this is handled by creating or exchanging shares. You would probably start out owning 100% of it -- say there are 100 shares. If you sell so

If you incorporate, this is handled by creating or exchanging shares. You would probably start out owning 100% of it -- say there are 100 shares. If you sell someone else one third to fund the business, they will own 50 shares (out of 150 now outstanding) and the company will get the money. So yes, they should expect a payout, even if they don't invest the next time you ask. And when you think about it, that makes sense: the opposite would be to sign a contract saying "I will invest $X in the company. And if they ask for more money, I will either give it to them or forfeit my investment." It would make it very easy for a startup to screw anyone who backed them.