Board Structure, Composition & Independence

NED Capital Knowledge Centre  |  Adrian Lawrence FCA, Founder

A company’s board structure is the governance architecture through which its directors exercise collective authority over the business — the combination of board size, composition ratios, independence requirements, committee structure and accountability relationships that determines how effectively the board can govern. Getting board structure right is one of the most consequential governance decisions a company makes, because the structure shapes who is in the room, what authority they hold and how effectively the board can exercise independent oversight of management.

This guide explains how UK company boards are structured, what the governance codes require, how independence is assessed and what different company types — listed, private, PE-backed and not-for-profit — need from their board structure to govern effectively.

The Legal Foundation of Board Structure

A company’s board structure is established at two legal levels: the Companies Act 2006, which defines directors’ legal duties and the company’s governance obligations; and the company’s articles of association, which set out the specific provisions governing how the board is constituted, how it meets, what constitutes quorum and how directors are appointed and removed.

The Companies Act 2006 requires every company to have at least one director who is a natural person (an individual rather than a corporate entity). For public companies, the minimum is two directors. Beyond these minimum requirements, the number and composition of the board is determined by the articles of association and, in practice, by the applicable governance code and the expectations of the company’s shareholders, investors and regulators.

The articles of association — the company’s constitutional document — typically specify: the minimum and maximum number of directors; the quorum required for board meetings; the process for appointing and removing directors; whether directors must retire by rotation and seek re-election; and any special provisions that require specific director types (for example, a requirement that a certain proportion of the board must be independent non-executive directors).

Board Composition — The Governance Code Requirements

The specific board composition requirements applicable to a company depend on its governance framework — primarily which governance code applies and whether the company has additional regulatory requirements.

FRC UK Corporate Governance Code (FTSE main market premium listed companies). The FRC Code requires that at least half of the board (excluding the chair) should be independent non-executive directors for FTSE 350 companies. For companies outside the FTSE 350, the Code requires that at least two members of the board should be independent NEDs. The chair should be independent on appointment. The CEO should not go on to become chair of the same company (unless exceptional circumstances are clearly explained). The FRC Code operates on a comply-or-explain basis — companies may depart from specific provisions but must explain departures in their annual report.

QCA Corporate Governance Code (AIM and smaller listed companies). The QCA Code requires a board that has an appropriate combination of skills, experience, independence and knowledge. AIM Rule 26 requires AIM companies to adopt and disclose their application of a recognised corporate governance code — the QCA Code is the most commonly adopted. The QCA Code does not specify the exact proportion of independent NEDs required, but expects at least two independent NEDs and explicitly expects board composition to include sufficient independence to provide objective oversight of management.

Private companies (no applicable code). Private companies are not subject to any governance code by default. Their board structure is entirely voluntary beyond the Companies Act minimum. In practice, private company boards that are PE-backed or approaching institutional investment adopt governance structures that broadly follow the spirit of the governance codes — balanced composition, meaningful independence and committee oversight — because investors expect and require it. Owner-managed businesses at early stage typically have informal boards that formalise as the business grows and governance complexity increases.

Regulated financial services firms (FCA/PRA requirements). FCA and PRA-regulated firms face specific governance requirements under the Senior Managers and Certification Regime (SMCR) that overlay the governance code requirements. The FCA’s expectations for INED independence and the PRA’s requirements for board composition at dual-regulated firms are among the most prescriptive board structure requirements in the UK market. See our Financial Services NED Recruitment page for detailed treatment of regulated firm board structure.

Understanding Board Independence

Independence is the most important — and most frequently misunderstood — concept in board composition. An independent director is one whose judgement is not materially influenced by a relationship with the company, its management or its controlling shareholders that could compromise their ability to act in the interests of all shareholders rather than a specific constituency.

The FRC Code sets out specific circumstances that would cause the board to determine that a director is not independent. These are not absolute disqualifiers — the board may determine that despite one of these circumstances, the director remains independent — but each requires specific board consideration and, where the board determines the director is independent despite the circumstance, explanation in the annual report.

The FRC Code’s independence tests include:

Current or recent employment. A director who has been an employee of the company or group within the past five years would not normally be considered independent. This includes former executive directors who have transitioned to non-executive roles — the FRC Code’s “cooling off” period is five years from the date of leaving employment, not from the date of the non-executive appointment.

Material business relationship. A director who has, or has had within the past three years, a material business relationship with the company — either directly or as a partner, shareholder, director or senior employee of a body that has such a relationship — would not normally be considered independent. This includes former advisers, auditors and consultants whose firms have material relationships with the company.

Additional remuneration. A director who receives or has received additional remuneration from the company beyond the standard NED fee — including participation in the company’s share option or performance-related pay scheme — would not normally be considered independent. NEDs who receive performance-related pay have a financial interest in the company’s short-term performance that compromises the objective oversight function independence is designed to provide.

Cross-directorships. A director who has close family ties with any of the company’s advisers, directors or senior employees, or who has significant links with other directors through involvement in other companies or bodies, may have their independence compromised. Cross-directorships — where two directors each serve on the other’s board — are a specific independence concern that boards should actively monitor and disclose.

Significant shareholder representation. A director who represents a significant shareholder — one who holds a substantial equity stake in the company — is not normally considered independent, because their governance function is to represent the interests of a specific shareholder rather than to exercise objective judgement in the interests of all shareholders. The threshold for “significant” shareholding that affects independence is a matter of board judgement.

Tenure exceeding nine years. A director who has served on the board for more than nine years from the date of first appointment is not normally considered independent unless the board provides a specific explanation. This is a rebuttable presumption — not an absolute limit — but it creates a strong governance expectation that tenure should be managed proactively to avoid widespread board over-tenure.

Board Size — What Is Right?

The optimal board size depends on the company type, complexity and governance code requirements. There is no universal answer, but governance research and practice have identified consistent patterns across different company categories.

FTSE 100 boards typically comprise 9–13 directors — the chair, 2–4 executive directors (CEO, CFO, and sometimes others) and 5–8 independent NEDs. The larger FTSE 100 companies tend toward the upper end of this range; smaller FTSE 100 companies toward the lower. Boards substantially larger than 13 members are generally regarded as too large for effective governance — the research evidence consistently shows that board effectiveness diminishes as size increases beyond a certain point because the dynamics of large group discussion inhibit genuine deliberation.

FTSE 250 boards typically comprise 7–10 directors, with the same general structure (chair, 2–3 executives, 4–6 NEDs).

AIM and smaller listed company boards typically comprise 5–7 directors — chair, CEO, CFO and 2–3 independent NEDs. The minimum to satisfy QCA Code independence requirements (at least two independent NEDs) and committee composition requirements (audit and remuneration committees each need at least two independent NEDs) practically requires a minimum of 5 directors with 2 independent NEDs.

PE-backed company boards typically comprise 5–7 members — CEO, CFO, 1–2 investor representatives, 1–2 independent NEDs and sometimes an independent chair. The PE governance structure is typically smaller and more commercially focused than equivalent listed company boards.

Private company boards should have a minimum of 3 directors (typically founder/CEO, CFO and at least one independent NED) to provide meaningful governance. Family company boards often include family members alongside independent directors, which raises independence management challenges discussed further in the independence section above.

Committee Structure

Board committees are sub-committees that exercise specific delegated governance authority on behalf of the full board. For listed companies, three committees are standard under the FRC Code; for other company types, committee structure should reflect the governance requirements of the specific business.

Audit committee. Required for all FRC Code companies and expected for QCA Code companies. The FRC Code requires a minimum of three independent NEDs, with at least one having recent and relevant financial experience (typically a qualified accountant with senior financial reporting or auditing experience). The audit committee oversees the integrity of financial reporting, the external audit relationship, internal controls effectiveness and the internal audit function. For regulated financial services firms, the audit committee has specific responsibilities under the FCA’s systems and controls framework.

Remuneration committee. Required for all FRC Code companies and expected for QCA Code companies. Must be composed entirely of independent NEDs (at least three for FTSE 350, at least two for other listed companies). The remuneration committee determines executive director remuneration — base salary, bonus structure, long-term incentive plans and pension arrangements. Executive directors may not serve on the remuneration committee or participate in determinations about their own remuneration.

Nomination committee. Required for all FRC Code companies and expected for QCA Code companies. Should be chaired by the board chair or an independent NED (with the board chair not chairing when the committee is dealing with the appointment of their successor). The nomination committee leads board appointment processes, maintains the board skills matrix, oversees board succession planning and monitors board effectiveness in conjunction with the annual evaluation process.

Risk committee. Required for systemically important financial institutions and dual-regulated firms under PRA requirements. Increasingly common in large listed companies and complex organisations as the risk oversight function has grown too substantial for the audit committee to accommodate alongside its financial reporting responsibilities. Typically chaired by an independent NED with risk management experience.

Other committees. Some companies operate additional committees — a technology or digital committee, an ESG committee, a safety committee (in industrial companies) or an investment committee (in financial services) — where specific governance functions require more focused oversight than the full board or standard committees can provide.

Board Structure for Private Companies — Building for Growth

Private companies that are approaching PE investment, an IPO or significant institutional governance for the first time face specific board structure decisions that determine how effectively they can make the governance transition.

When to appoint the first NED. The optimal timing for a first NED appointment is 18–24 months before a planned PE fundraise or institutional governance transition — early enough to establish a governance track record that investors can evaluate, and late enough that the NED has context about the business when the governance challenge is most significant. See our High-Growth Board Governance Before PE page for detailed guidance on this transition.

Separating the chair and CEO roles. The FRC Code prohibits the combined chair-CEO role for premium listed companies. For private companies, separation is best practice rather than mandatory — but the governance rationale for separation is equally valid regardless of listing status. A board on which the CEO also chairs the board meetings, sets the agenda and manages the other directors has no meaningful external governance oversight. Where a founder serves as executive chair, this creates a different governance dynamic from a pure chair-CEO combination but still requires careful management of the independence and accountability relationship with the non-executive board members.

Phased committee development. Private companies approaching governance formalisation typically develop committee structure in phases — establishing an audit function first (financial oversight is the most immediate independent governance requirement), then remuneration governance (often triggered by the need to manage executive pay in a PE context or ahead of listing) and finally a formal nomination function when board composition management becomes a sustained governance priority rather than a one-off activity.

Independence Management in Practice

Managing independence effectively requires active attention rather than passive compliance. Several practical governance actions support effective independence management.

Conduct a formal independence assessment annually for each NED — not a perfunctory confirmation that circumstances have not changed, but a genuine re-evaluation of each director’s independence status against the current FRC Code criteria, including any new business relationships, family connections or cross-directorships that have arisen during the year. Document the assessment in the nomination committee’s minutes and, for listed companies, reflect the outcome in the annual report independence disclosure.

Manage tenure proactively. Directors approaching the nine-year limit should be identified well in advance — the succession planning calendar should show nine-year limits alongside term expiry dates so that independence pressures are anticipated rather than reacted to. Where the board determines to retain a director beyond nine years with an explanation, the explanation should be substantive and specific rather than a generic statement of the director’s continuing contribution.

Address conflicts of interest formally. Related party transactions, cross-directorships and other circumstances that create potential conflicts of interest between a director’s independence obligation and other relationships should be declared, recorded and managed through a formal process — not managed informally or overlooked because the circumstances are minor. The accumulation of minor undisclosed conflicts is a significant governance risk that formal conflict management processes prevent.

Related guides: What Is Corporate Governance?  |  What Is a Board Meeting?  |  Board Skills Matrix Templates  |  Board Composition Reviews  |  NED Knowledge Centre

NED Capital advises on board structure and places non-executive directors for companies across the UK. Call 0203 137 2496 or see our NED Recruitment Agency page to discuss a board appointment.