[qiemem]

CHAR(8)

[mistercow]

Worse yet, it seems to imply that they aren't hashing, which is simply preposterous for a financial institution.

[codesuela]

Many banks require you to use numbers only for your pin a smart engineer probably figured that cracking 10 char numerical "passwords" is trivial so hashing would be a waste of resources and hence energy and emissions. It is greener that way.