In the hectic times after my divorce and relocating, new bank accounts, I missed payments for the first time in my life. I was more concerned with with the penalties for not paying anything. I called up and they refunded most of my penalties. Not sure what it did to my credit score.

Usually when I switch bank accounts, I leave the old one open with some money in it for a while so I can make sure I got everything. I also maintain a document with all my bills and account numbers and how/when they are paid.