I think it depends. There are two sides to this and two ways of looking at it. You were allegedly a partner yet you say you 'left the business in 2010'. If this is the case what is someone who is your partner to do? If it is unworkable to manage without you in the existing set up, and you aren't there, I don't see that he had any choice but to stop himself. The fact that he then restructured work he was obviously experienced with and set up a new company as a sole trader is neither here nor there to your original problem and it would not be in his interest to buy you out of a non trading company. That part is very simple. The difficulty arises if you were indeed legal partners and he dissolved the company without your agreement, or if he is possibly still using the domain name etc, but it's unreasonable and illogical to think that he wouldn't set up his own company doing exactly what he was before because that's what most people would do. Get some good legal advice and see what you can salvage, as someone else said it should be part of your divorce settlement.