Moreover, credit unions seem to have good relationships with each other. I've never actually even seen a branch of the credit union I've been using for ten years in real life. But, if I need a notarization or to deposit a cheque, I can easily visit a branch of any credit union and they are usually happy to do it for me.
I've been hit with fines for my mistakes (transferring money out of the wrong account) but I've never paid them since they are always willing to remove them via a simple text chat. (I find text chats much easier than phone calls, too.)
The majority of credit unions share a vendor that handles a lot of their logistics for them. That's one of the reasons why they're so accommodating about certain inter-credit-union transactions. It's a value added service of a shared vendor, who just pushes some numbers around in a database.
I've been hit with fines for my mistakes (transferring money out of the wrong account) but I've never paid them since they are always willing to remove them via a simple text chat. (I find text chats much easier than phone calls, too.)