Well the simple way to look at this is that usually when you transact with another bank, you're required to have an account at that bank. Just as a consumer can

Well the simple way to look at this is that usually when you transact with another bank, you're required to have an account at that bank. Just as a consumer can't magically change their balance, a bank simply can't magically increase their balance at other banks. To perform increased transactions, you have to send money to that bank.