Overview
Alternative Investment Fund Managers (AIFMs) are categorised into three regulatory classifications under the UK AIFM regime: Full-Scope, Small Authorised and Small Registered. [1]
As at Q4 2025, there are 1,284 total UK AIFMs based on the total number of authorised and registered entities 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 the remaining consisting of 133 Small Registered AIFMs (10.4%).
| Class |
Firm Count |
% of Total |
| Full-Scope |
685 |
53.3% |
| Small Authorised |
466 |
36.3% |
| Small Registered |
133 |
10.4% |
| Total |
1,284 |
100% |
Classification Types & Criteria
The classification of UK AIFMs is determined by their applicable Assets under Management (AUM) thresholds, which define the scope of regulatory obligations: [2]
Above AUM Threshold:
Full-Scope AIFMs:
AIFMs with aggregate AUM of at least €100 million (including leverage), or at least €500 million for unleveraged AIFs with a minimum five-year investor lock-in. These firms are subject to the full UK AIFM regime, including capital requirements, risk and liquidity management, valuation, depositary appointment, and regulatory reporting.
Sub-threshold:
Small Registered AIFMs:
AIFMs with aggregate AUM below the applicable threshold that are subject to registration rather than authorisation, with limited ongoing obligations focused on registration and reporting.
Small Authorised AIFMs:
AIFMs with aggregate AUM below the applicable threshold that require, or elect to obtain, authorisation under Part 4A of FSMA. These firms are subject to authorisation and the applicable requirements of the UK AIFM regime.
Proposed Classification Changes
In April 2025, HM Treasury opened a consultation regarding reforms to the UK AIFM regime alongside an FCA call for input. [3,4] The proposals would replace statutory AUM thresholds with a three-tier classification in FCA rules (large, mid-sized, small), use net asset value (NAV: assets minus liabilities) as the size metric, require firms to notify the FCA of their category with an option to opt-up, and reorganise requirements into thematic modules aligned to business activities and the product lifecycle.
Proposed NAV-based thresholds:
Large AIFMs:
NAV ≥ £5 billion; a regime broadly similar to current full-scope requirements, covering governance, risk management, and reporting.
Mid-sized AIFMs:
£100 million ≤ NAV < £5 billion; the same regulatory areas would apply with less prescriptive procedural detail.
Small AIFMs:
NAV < £100 million; baseline standards under a simplified entry-level regime replacing the current sub-threshold registration/authorisation categories, with ongoing obligations and limited reporting.
Additional Features:
• Notification to the FCA of a firm’s category (rather than prior approval for classification changes).
• Voluntary opt-up to a higher tier.
• Rules reorganised into thematic modules (e.g., firm governance and systems; pre-investment; during investment; change-related).
See Also
Dataset of UK AIFMsRegulated Activities of UK AIFMs