What Does a Controller Do? Role, Responsibilities, and Skills
A financial controller runs a company's accounting operations, the books, the close, reporting, and controls. Here is what a controller does, their core responsibilities, how the role differs from a CFO, the skills it takes, and how AI is changing it.
Every company that takes its numbers seriously has someone who owns them. That person is usually the financial controller. The controller runs the accounting engine of the business, making sure every transaction is recorded correctly, the books close on time, the financial statements are accurate, and the controls hold. It is one of the most important and least understood roles in finance.
This guide explains what a controller does, their core responsibilities, how the role differs from a CFO, the skills it takes, and how AI is changing it.
What is a financial controller?
A financial controller is the senior accounting leader responsible for a company's day-to-day accounting operations and the integrity of its financial records. They own the general ledger, the month-end close, financial reporting, and the internal controls that keep the numbers accurate and auditable. The controller typically reports to the CFO and leads the accounting team.
If the CFO is responsible for where the company is going financially, the controller is responsible for knowing exactly where it is right now. The controller owns the truth of the numbers.
What does a controller do? Core responsibilities
- Owns the close. Runs the month-end close, ensuring the books are closed accurately and on time each period.
- Manages the general ledger. Oversees the GL, journal entries, and reconciliations so every balance ties to source.
- Produces financial statements. Prepares the income statement, balance sheet, and cash flow statement, and the reporting leadership and auditors rely on.
- Maintains internal controls. Designs and enforces the controls (including SOX, where applicable) that prevent errors and fraud.
- Manages the accounting team. Leads accountants and AP/AR staff and sets accounting policy.
- Supports audit and compliance. Serves as the point person for external auditors and ensures GAAP compliance.
Controller vs. CFO
| Controller | CFO | |
|---|---|---|
| Focus | Accuracy of the numbers (backward-looking) | Strategy and the future (forward-looking) |
| Owns | Accounting, the close, reporting, controls | Finance strategy, capital, fundraising, investors |
| Question | Are the numbers right? | What do we do with them? |
| Reports to | The CFO | The CEO and board |
In smaller companies one person may wear both hats, but as a business grows the roles separate: the controller ensures the numbers are right, and the CFO decides what to do with them. Between them sometimes sits a financial controller's counterpart on the cash side, the treasurer.
Skills of a great controller
- Deep accounting expertise. Mastery of GAAP, the close, and financial reporting, often with a CPA.
- Precision and control. An instinct for accuracy, documentation, and auditability.
- Process and systems. The ability to run a repeatable close and manage the accounting tech stack.
- Leadership. Managing and developing an accounting team under deadline pressure.
- Communication. Translating the numbers for the CFO, the board, and auditors.
How AI is changing the controller role
The controller role is being reshaped by AI, because so much of what controllers oversee, reconciliations, journal entries, the close, and reporting, is exactly the high-frequency, rules-plus-judgment work AI agents handle well. Rather than the accounting team doing all of it by hand, agents can run the recurring work while the controller reviews, approves, and owns the judgment and controls.
This does not replace the controller; it elevates the role. The controller shifts from running the mechanics to directing the systems that run them, with every number still traceable to source and defensible to an auditor. See how this works in AI agents for controllers.
Frequently asked questions
What does a financial controller do?
A financial controller runs a company's accounting operations: the general ledger, the month-end close, financial statements, internal controls, and the accounting team. They ensure the numbers are accurate, on time, and auditable, and typically report to the CFO.
What is the difference between a controller and a CFO?
The controller owns the accuracy of the numbers, accounting, the close, reporting, and controls, and is backward-looking. The CFO owns financial strategy, capital, fundraising, and investor relations, and is forward-looking. The controller usually reports to the CFO.
What skills does a controller need?
Deep accounting expertise (often a CPA), precision and a controls mindset, process and systems skills to run a repeatable close, team leadership, and the ability to communicate the numbers to the CFO, board, and auditors.
How is AI changing the controller role?
AI agents now handle much of the recurring work controllers oversee, reconciliations, entries, the close, and reporting, while the controller reviews, approves, and owns the judgment and controls. The role shifts from running the mechanics to directing the systems that run them.
The bottom line
The financial controller is the owner of a company's accounting truth: the close, the general ledger, financial statements, and the controls that keep them accurate. It is a role defined by precision and accountability, and it is being elevated by AI, which takes the mechanical work so the controller can focus on judgment, controls, and leadership.
If you want AI agents to run the recurring accounting work your controllership oversees, with every number traceable and a human approving, talk to our team.
