According to the regulations of the State Administration of Foreign Exchange, all commercial banks will not change them. They only accept paper money, and require that the value of a single sheet be above 1 USD, and generally require more than 80% new. Don't accept banknotes and coins that are too old.

Foreign banks love the poor very much, and it is even more impossible to handle this kind of business (even if they handle the handling fee, it will definitely scare people to death) ...