A lot of us may have some unclaimed property from old bank accounts, rebates, and over payments of bills. Most state controllers have a site where you can make a claim from their database. Here is an example from California.
“California’s Unclaimed Property Law requires corporations, businesses, associations, financial institutions, and insurance companies (referred to as “Holders”) to annually report and deliver property to the California State Controller’s Office after there has been no activity on the account or contact with the owner for a period of time specified in the law - generally (3) three years or more.”
I got around $40 from Sprint 5 years ago using a state unclaimed funds search. Also found about $2k for my grandpa in California (utility credits, I believe). Can be very helpful, especially if you’ve moved between states.