bean counter 
noun informal
A person, typically an accountant or bureaucrat, perceived as placing excessive emphasis on controlling expenditure and budgets: their bean counters will switch to a new way of calculating GDP...
- Enter the bean counter as Southwest's costs grow
- A bean counter will say you should respond by cutting in other places, which usually means shifting the burden onto other people, especially your employees.
- As a small business owner, you are not only the head honcho, but also the bean counter, chief salesman, IT boffin, tax specialist and marketing guru too.