A chief financial officer runs the finance function and, in most companies, sits on the board. What the title does not carry is statutory weight: the Companies Act 2006 imposes no requirement to appoint a CFO and does not define the role. The duties that bite come from being a director, not from the job title — and in one sector, academy trusts, the CFO requirement is real and about to get harder.
The role in outline
The CFO owns the numbers and the systems that produce them: financial reporting and the statutory accounts, planning and forecasting, cash and treasury, tax compliance, the control environment, and the relationships with auditors, lenders and investors. In a growing business the role usually arrives when the finance function outgrows a financial controller — when someone has to sit in strategic conversations with the authority to say what the business can afford.
That is a description of practice rather than of law. Unlike a company secretary — where the Companies Act says expressly that a private company is not required to have one, and provides for what happens when there is none — there is no statutory scaffolding around the CFO at all.
What actually creates the obligations
If the CFO is appointed to the board, they are a director, and the general duties in Part 10 of the Companies Act 2006 apply in full:
- Section 171 — act in accordance with the constitution, and only exercise powers for the purposes for which they are conferred;
- Section 172 — act in good faith to promote the success of the company for the benefit of the members as a whole, having regard to long-term consequences, employees, supplier and customer relationships, community and environmental impact, reputation, and fairness between members;
- Section 173 — exercise independent judgment;
- Section 174 — exercise reasonable care, skill and diligence;
- Section 175 — avoid conflicts of interest, including exploitation of property, information or opportunity;
- Section 176 — do not accept benefits from third parties conferred by reason of being a director;
- Section 177 — declare an interest in a proposed transaction before the company enters into it.
Section 174 is the one that falls hardest on a finance director. The standard has two limbs: objectively, the general knowledge, skill and experience reasonably expected of someone carrying out that director's functions; and subjectively, the director's own actual knowledge, skill and experience. A qualified accountant on the board is judged against what a qualified accountant should have known — the subjective limb raises the bar, it does not lower it.
The duties are owed to the company, and several continue after a director leaves.
Senior accounting officer
For larger groups, the tax equivalent of a personal accountability regime is the senior accounting officer requirement. A qualifying company is one with, either alone or aggregated with other UK companies in the same group, turnover exceeding £200 million and/or a relevant balance sheet total exceeding £2 billion in the preceding financial year. Either test alone is enough.
Only UK-incorporated companies are in scope, and the determination has to be made for each financial year — a group that crosses the line does not get a grace period. "Turnover" takes its Companies Act meaning. The SAO is usually, though not necessarily, the CFO, and the appointment carries personal obligations around appropriate tax accounting arrangements. Our guide to the senior accounting officer regime covers the duty in detail.
Governance: Provision 29 is now live
For listed companies, the UK Corporate Governance Code applies on a comply-or-explain basis to companies in the commercial companies or closed-ended investment funds categories, regardless of where they are incorporated. The 2024 Code applies to financial years beginning on or after 1 January 2025.
Provision 29 applies to financial years beginning on or after 1 January 2026 — so for a calendar-year company it is live now. The board must monitor the risk management and internal controls framework and review its effectiveness at least annually, covering all material controls: financial, operational, reporting and compliance. It must then make a declaration on the effectiveness of material internal controls.
Which controls are "material" is company-specific and determined by the board, and external assurance over them is a matter for each board rather than a requirement. In practice this lands on the CFO, because the evidence base — control documentation, testing, remediation tracking — has to exist before a declaration can honestly be made.
The exception: academy trusts
One sector does mandate the role. The Academy Trust Handbook 2026, effective 1 October 2026, requires the board to appoint a chief financial officer to whom responsibility for the trust's detailed financial procedures is delegated. Finance staff should be appropriately qualified or experienced, assessed against the trust's risk, scale and complexity.
There is a deadline attached. For trusts with more than 3,000 pupils the Handbook says the CFO should hold a professional accountancy qualification, and that new CFO recruitment should specify a qualified accountant with relevant professional body membership or the CIPFA level 7 qualification. From 1 September 2027 that becomes a must, unless DfE receives advance notice with justification. Our guide to the Academy Trust Handbook sets out the wider requirements.
When a business needs one
The honest answer is that most businesses need the capability before they need the headcount. The trigger is usually one of: a transaction in prospect, external funding that brings reporting obligations, a control environment that has outgrown the people running it, or a management team making decisions on numbers nobody owns.
A part-time or interim CFO covers that gap without committing to a senior salary, and it is often the right first step — particularly where the need is a specific project rather than a permanent function. What does not work is leaving the role unfilled and assuming the auditors will catch what goes wrong; they are looking at a different question, at a materiality level set for the accounts rather than for the business.
Acumon provides finance leadership through interim accountant and CFO services and an outsourced finance function, with management accounts and corporate governance support alongside — see also our guide to the outsourced finance function. If your board is making decisions on management accounts nobody has signed off, that is the gap to fill first.