There are people who steal the identity of the dead. I don't know how easy that is to do now but it has been done in the past. In fact, my now deceased MIL was agressivley courted by a man who had done this in the past. We were able to get her to see him for what he was but he was a lifelong criminal. Can't be too careful.
Check with the bank. It used to matter if the checks said "and" so and so, or "or" so and so. I don't think that matters anymore. When my dad died, I never had to change a thing on Mom's account, but you need to call the bank and ask them what their rules are. Take care, Carol
Take care,
Carol