Impax Asset Management provides portfolio management for individuals and small businesses, portfolio management for investment companies, portfolio management for pooled vehicles, and portfolio management for institutions.
Impax Asset Management reports 686 clients. They include 562 high-net-worth individuals, 33 individual clients and 27 pooled investment vehicles. Of its assets, 94.6% ($24.4B across 676 accounts) are managed with discretion; $1.39B across 10 accounts are not. A wrap fee program the firm both sponsors and manages holds $149M. Of its clients, 8% are outside the U.S. It advised 10 clients without assets under management last fiscal year.
| Client type | Clients | Assets |
|---|---|---|
| Individuals (other than HNW) | 5% | <1% |
| High-net-worth individuals | 82% | <1% |
| Investment companies | <1% | 9% |
| Pooled investment vehicles | 4% | 70% |
| Pension and profit-sharing plans | 1% | 3% |
| Other client typesCharitable organizations; State or municipal government entities; Other investment advisers; Corporations and other businesses; Other | 7% | 17% |
Client breakdown and activity details
| Client type | Clients | Regulatory AUM | AUM share | Avg. per client |
|---|---|---|---|---|
| Individuals (other than HNW) | 33 | $7.15M | 0.0% | $217K |
| High-net-worth individuals | 562 | $218M | 0.8% | $389K |
| Investment companies | 4 | $2.25B | 8.7% | $561M |
| Pooled investment vehicles | 27 | $18B | 69.7% | $667M |
| Pension and profit-sharing plans | 9 | $894M | 3.5% | $99.3M |
| Charitable organizations | 7 | $12.8M | 0.0% | $1.82M |
| State or municipal government entities | 3 | $1.47B | 5.7% | $489M |
| Other investment advisers | 11 | $1.57B | 6.1% | $143M |
| Corporations and other businesses | 17 | $14.3M | 0.1% | $840K |
| Other | 13 | $1.39B | 5.4% | $107M |
| Total | 686 | $25.8B | 100% | $37.7M |
- Clients
- 33
- Regulatory AUM
- $7.15M
- AUM share
- 0.0%
- Avg. per client
- $217K
- Clients
- 562
- Regulatory AUM
- $218M
- AUM share
- 0.8%
- Avg. per client
- $389K
- Clients
- 4
- Regulatory AUM
- $2.25B
- AUM share
- 8.7%
- Avg. per client
- $561M
- Clients
- 27
- Regulatory AUM
- $18B
- AUM share
- 69.7%
- Avg. per client
- $667M
- Clients
- 9
- Regulatory AUM
- $894M
- AUM share
- 3.5%
- Avg. per client
- $99.3M
- Clients
- 7
- Regulatory AUM
- $12.8M
- AUM share
- 0.0%
- Avg. per client
- $1.82M
- Clients
- 3
- Regulatory AUM
- $1.47B
- AUM share
- 5.7%
- Avg. per client
- $489M
- Clients
- 11
- Regulatory AUM
- $1.57B
- AUM share
- 6.1%
- Avg. per client
- $143M
- Clients
- 17
- Regulatory AUM
- $14.3M
- AUM share
- 0.1%
- Avg. per client
- $840K
- Clients
- 13
- Regulatory AUM
- $1.39B
- AUM share
- 5.4%
- Avg. per client
- $107M
Total
- Clients
- 686
- Regulatory AUM
- $25.8B
- AUM share
- 100%
- Avg. per client
- $37.7M
- Clients outside the U.S.
- 8%
- Clients advised without assets under management last fiscal year
- 10
- Private funds advised
- 0
Impax Asset Management is paid through a percentage of assets under management and performance-based fees; its fees and minimums are set out in its brochures on the SEC website.
Impax Asset Management Group PLC owns 75% or more of Impax Asset Management. Ian Simm is CEO; the leadership team includes Chief Operating Officer Darren Johnson, Chief Financial Officer Karen Cockburn and Chief Compliance Officer John Boese. It has 165 employees, 53 of them in advisory roles.
Leadership
Ian SimmDirector, Chief Executive Officer
Karen CockburnDirector, Chief Financial Officer
Darren JohnsonGlobal Chief Operating Officer
John BoeseChief Compliance Officer
Staff
- 165 employees
- 53 in advisory functions
- 1 soliciting firm
- Owns 75% or more of Impax Asset Management, LTD.
Impax Asset Management Group PLC
Control person · since June 1998
Impax Asset Management’s regulatory assets grew from $20B (March 2021) to $25.8B (December 2025); clients rose from 220 to 686 and employees from 119 to 165.
Figures from each annual filing
| Filed | Regulatory AUM | Clients | Employees | Offices |
|---|---|---|---|---|
| December 2025 | $25.8B | 686 | 165 | 1 |
| December 2024 | $40.6B | 953 | 187 | 1 |
| December 2023 | $36.6B | 1,217 | 175 | 1 |
| January 2023 | $32.2B | 1,372 | 155 | 1 |
| April 2022 | $41.1B | 1,251 | 133 | 2 |
| March 2021 | $20B | 220 | 119 | 3 |
Besides its headquarters, Impax Asset Management has 0 offices, with 1 listed address with no US state reported.
Contact and registration details
- Legal name
- Impax Asset Management, LTD.
- Headquarters
- 7th Floor, 30 Panton Street, London, United Kingdom SW1Y 4AJ
- Website
- impaxam.com
- Phone
- 011442039123000
- SEC file
- 801-67631
- Structure
- other (specify) organized in United Kingdom
- Fiscal year end
- September
Impax Asset Management uses BNP Paribas S.a. ($1.02B, 29%), HSBC ($792M, 22%) and The Bank of New York Mellon ($729M, 20%), among others, as custodians for its separately managed accounts. Impax Asset Management does not have custody of client assets.
- The Bank of New York MellonThe Bank of New York Mellon · New York (US) & Ontario (Ca), NY · $729M20%
- HSBCHSBC · London · $792M22%
- J.P. MorganJP Morgan · London (Uk), Melborne & New York · $462M13%
- BNP Paribas S.a.BNP Paribas S.a. · Wellington (NZ), Paris (FR) · $1.02B29%
- CitibankCitibank · Bertrange · $563M16%
At year end, Impax Asset Management’s separately managed accounts were mostly in stocks (96%).
What the accounts hold
- Stocks96%
- Bonds1%
- Cash3%
How many clients does Impax Asset Management have?
Impax Asset Management has 686 clients and manages $25.8 billion for them, as of December 2025. They include 562 high-net-worth individuals, 33 individual clients and 27 pooled investment vehicles.
Source: Form ADV Part 1A, Items 5.D and 5.F, filed 22 December 2025
What services does Impax Asset Management offer?
Impax Asset Management provides portfolio management for individuals and small businesses, portfolio management for investment companies, portfolio management for pooled vehicles, and portfolio management for institutions.
Source: Form ADV Part 1A, Item 5.G, from the SEC's 2 October 2026 data file
Which custodians does Impax Asset Management use?
Impax Asset Management’s separately managed account assets are held at BNP Paribas S.a. (Wellington (NZ), Paris (FR)), with $1.02B, HSBC (London), with $792M, The Bank of New York Mellon (New York (US) & Ontario (Ca), NY), with $729M, Citibank (Bertrange), with $563M and JP Morgan (London (Uk), Melborne & New York), with $462M. Only custodians holding at least a tenth of those assets are named.
Source: Form ADV Part 1A, Schedule D, Section 5.K.(3), filed 22 December 2025
How many financial advisors does Impax Asset Management have?
Impax Asset Management has 0 investment adviser representatives registered with state securities authorities, out of 165 employees, and 53 perform investment advisory functions. None are registered representatives of a broker-dealer or licensed insurance agents.
Source: Form ADV Part 1A, Items 5.A and 5.B, from the SEC's 2 October 2026 data file
What does Impax Asset Management invest in?
At the end of its last fiscal year, Impax Asset Management’s separately managed accounts held 96% exchange-traded equities, 3% cash and equivalents and 1% high-yield corporate bonds.
Source: Form ADV Part 1A, Items 5.K.(1) and 7.B, from the SEC's 2 October 2026 data file
Who owns Impax Asset Management?
Impax Asset Management’s direct owner is Impax Asset Management Group PLC (75% or more).
Source: Form ADV Part 1A, Schedules A and B, filed 22 December 2025
How does Impax Asset Management get paid?
Impax Asset Management is paid through a percentage of assets under management and performance-based fees. Its Form ADV lists no commissions among how it is paid.
Source: Form ADV Part 1A, Item 5.E, from the SEC's 2 October 2026 data file
How do I contact Impax Asset Management?
Impax Asset Management’s main office is at 7th Floor, 30 Panton Street, London, United Kingdom SW1Y 4AJ. Its phone number is 011442039123000. Its website is impaxam.com.