Sure, there's nothing wrong with costing a company money. There's also nothing wrong with costing a person money - for example: if I make a bid at an auction i

Sure, there's nothing wrong with costing a company money. There's also nothing wrong with costing a person money - for example: if I make a bid at an auction it causes another bidder to pay more. The point is that you should treat others like you want to be treated. Do you want people to break their word to you? If not, don't break your word to them, even if they have formed a group which is legally recognised as a company. Also consider that it is possible for a single person to form a 'company' to run his business - is it OK to break your word to this person? Or only when he takes on a business partner?