I keep copies of key documents all in one place, my Personal Reference Binder, and it’s stored away from my house, so if there was a fire or flood or whatever, I’d still have the information. I also scan most of the documents and save them to a cloud service, which came in handy when I was travelling and needed to find the phone number to call on the back of a debit card that was stolen! Here’s the list of my binder:

Personal Reference Binder