How can I protect my commission with a failing business?
You don't have any good options. All contracts contain an extra unwritten term, one added by the law: the "implied covenant of good faith and fair dealing." (That's the traditional term; it's possible your state has a different term for it.) This obligates the other side to not deliberately take steps or do things to destroy the purpose or value of the contract to you--such as, for example, deliberately delaying closings or works when they don't otherwise have to, to avoid paying earned commissions. If they violate this covenant by acting in bad faith, you could sue them for the breach, to get your money. But the reason this is not a good option is that, as you can imagine, "good faith" is a subjective thing--there is no hard-and-fast definition of what is good faith or not, but rather it's up to the court, on a case-by-case basis, to decide what is and is not good faith. It can be hard to convince a court that someone acted in bad faith if there they can put up *any* plausible explanation for their actions or a delay--e.g. a cash flow shortage or difficulties, which is highly plausible if the buisness has been having difficulties. You might not be able to prove their bad faith so as to win the lawsuit.