There it's two records in two banks (in the general case) for each transaction. The sum must check out to be zero. And beside that there are laws that are enfor

There it's two records in two banks (in the general case) for each transaction. The sum must check out to be zero. And beside that there are laws that are enforced because it is not legal to create money out of thin air. Ok, it is done anyway (when the government prints more money and thus increases inflation) and to a degree banks are allowed to do that in some sense as well (they loan can a certain percentage more money than they actually have). The whole system isn't perfect (hence the economic crisis), but there are enforced laws that aren't written by companies (well, mostly).