cashier; accountant; treasurer
Refers to a person responsible for handling money, keeping accounts, or managing finances in a shop, office, or organization. The exact role depends on context.
He works as a cashier at that store.
The accountant handles the bookkeeping tasks.
レジ係 is a cashier at a register, more common in retail settings, while 勘定係 is broader and can include back-office accounting roles.
Compound of 勘定 (かんじょう, 'calculation, bill, account') and 係 (がかり, 'person in charge').