A Mid-Sized UK AIFM is a proposed size-based category for UK alternative investment fund managers whose alternative investment funds have an aggregate net asset value (NAV) of more than £100 million and up to £5 billion. The term is used in the Financial Conduct Authority’s (FCA) April 2025 Call for Input on the future regulation of alternative fund managers as the middle band between small and large AIFMs.
Existing UK AIFM Classification
Under the existing UK AIFM regulatory classification, derived from the onshored Alternative Investment Fund Managers Directive (AIFMD), firms are grouped for regulatory purposes as:
• Full-scope UK AIFMs, where assets under management (AUM) exceed specified legislative thresholds (broadly, €100 million if leverage is used or €500 million if the AIFs are unleveraged and closed-ended for at least five years).
• Small authorised UK AIFMs, which are authorised but remain below those thresholds.
• Small registered UK AIFMs, which are registered rather than authorised and mainly manage particular types of AIF (for example, certain property schemes, RVECA funds or social entrepreneurship funds).
As at Q4 2025, there are 1,284 UK AIFMs based on the total number of authorised and registered AIFMs regulated by the FCA. Full-Scope AIFMs make up the majority (685 firms, or 53.3%), followed by 466 Small Authorised AIFMs (36.3%) and 133 Small Registered AIFMs (10.4%).
To introduce more proportionality by size, the FCA’s April 2025 Call for Input proposes NAV-based bands for UK AIFMs:
• Small UK AIFM: NAV of £100 million or less.
• Mid-Sized UK AIFM: NAV of more than £100 million and up to £5 billion.
• Large UK AIFM: NAV of more than £5 billion.
A Mid-Sized UK AIFM would therefore be a UK AIFM whose aggregate NAV for relevant AIFs is greater than £100 million but does not exceed £5 billion.
Analysis in the FCA’s material indicates that:
• A substantial proportion of firms currently authorised as full-scope UK AIFMs fall within this intermediate NAV range.
• Many firms considered “sub-threshold” under the existing regime would reach the mid-sized band if their NAV grows beyond £100 million.
As at Q4 2025, “Mid-Sized UK AIFM” remains a proposed category. Its precise definition and regulatory consequences depend on future legislative changes and FCA rule-making.
Dataset of UK AIFMs
Core attributes
• 100% Firm Coverage: Comprehensive list of all 1,284 authorised and registered UK AIFMs.
• AIFM Classification: Segmentation of firms by regulatory class as Full-Scope, Small Authorised and Small Registered.
• Permitted Activities: Permissions held across AIFMD, UCITS & MiFID, plus S21 approver status and MiFID client types.
• Governance Structure: Visibility of leadership structure & depth through count of Senior Management Function roles.
• Company Structure: Company registration ID, legal form, incorporation & authorisation dates, region & key financials.
