It’s a difficult question because you really almost have to have a vision of the future in order to prevent something like that happening. If you live in a community property state like California, there is nothing that you can do to declare, “This was my business and I earned all of this money,” unless you had a prenup in place. The nature of community property laws are that if you are married and any of your earnings from your job, business, whatever you may have, that’s automatically 50/50 community property.
The only real way to prevent something like that happening is to have a prenup in place where you started from the start stating that what each party earns is their own property. Many couples will do this and keep their assets completely separate and then have a joint account to pay bills. But as far as being able to predict the future and know this business is going to explode and I am eventually going to get divorced, there’s not really a whole lot that you can do to once you’re at the point where you’re ready to divorce, you’ve had no prenup, you’ve had no post-nup, which is an option, you’re really stuck in the situation where you are going to be splitting your assets or whatever the divorce court decides is what you have to follow.