A controller is the head of accountant of the company. They supervise other accountants and oversee the preparation of financial reports. It exercises a line function. They are the one responsible for ensuring that all accounting allocations are appropriately made and documented. It exercises a line function.

A line function is one that is directly involved in the core operations of the company.

In smaller companies, the controller may also perform cash management functions and oversee accounts payable, accounts receivable, cash disbursements payroll and bank reconciliation functions.

The main duties of a controller are as follows:

1. Prepare budgets and determines expectations regarding future outcomes of different courses of actions (Control Planning)
2. Summarize financial data and present to the different levels of management (Internal Reporting and Interpreting)
3. Analyze financial data and give advice to management in making decisions (Evaluation and Consulting)
4. Supervising formulation and implementation of tax policies and consider its implications to tax-related decisions (Tax Administration)
5. Prepare financial statements according to the accounting standards (External reporting)
6. Implement internal controls to protect company assets against fraud, natural disasters, etc.
7. Assess the impact of economic, social and government influences to the business (Economic Appraisal)

A treasurer, on the other hand, serves as the protector of a company’s value and finances from financial risk that arises from business activities. He manages the company’s cash flows and ensure that the company meets the financial goals expressed in the budget.

The treasurer has a watchdog role over all aspects of financial management, working closely with other members of the Management Committee to safeguard the organization’s finances. It exercises a staff function.

Staff function provides support to the organization. They support the company by providing vital information to the management’s decision-making process.

A treasurer has the following responsibilities:

1. Interact with shareholders, bankers, current and potential investors (Investor Relations)
2. Obtain loans and other forms of credit from outside sources (Capital Provision)
3. Manage cash flow of the business
4. Oversee the extension of credits to customers (Credits and Collection)
5. Analyze investment prospects to maximize use of company’s unused cash and assets (Investment)
6. Use various hedging strategies in order to reduce risk related to changes in the value of company assets, and interest rates, etc.
7. Keep the bankers of the company updated to the company’s financial condition and projections as well as its possible needing of borrowed funds.

To summarize its differences, see the following comparison:

Sources: https://smallbusiness.chron.com/responsibility-financial-controller-47296.html
https://strategiccfo.com/duties-of-a-financial-controller/
https://www.accountingtools.com/articles/2017/5/14/treasurer-job-description
http://www.diycommitteeguide.org/resource/what-role-of-treasurer