| 3BM Limited | Professional & scientific | 2012 |
| Absolute Solar and Wind Ltd | Professional & scientific | 2008 |
| Acies Civil and Structural Limited | Professional & scientific | 2010 |
| Adas Silverdale Limited | Construction | 2018 |
| Advantage RSK Limited | Professional & scientific | 2021 |
| Affordable Skip Hire Bristol Limited | Water & waste | 2011 |
| Apollo Strategic Communications Limited | Professional & scientific | 2008 |
| Approved Roofing Contractors Ltd | Construction | 2025 |
| Argrennan Estate Limited | Real estate | 2022 |
| Argus Environmental Limited | Water & waste | 1992 |
| ATP Architects + Surveyors Limited | Construction | 2013 |
| Axis Well Technology Group Limited | Professional & scientific | 2013 |
| Axis Well Technology International Limited | Professional & scientific | 2017 |
| Axis Well Technology Management Limited | Professional & scientific | 2013 |
| Bateman Skips Ltd | Water & waste | 2003 |
| Binnie & Partners Limited | Professional & scientific | 2020 |
| Binnies UK Limited | Construction | 1996 |
| Britcom Technologies Limited | Other services | 2004 |
| BTS Group Limited | Agriculture & fishing | 2001 |
| Butler Veterinary Services Ltd | Professional & scientific | 2018 |
| CAN Geotechnical Limited | Construction | 2003 |
| CAN Limited | Extraterritorial | 2008 |
| CAN London Limited | Extraterritorial | 2003 |
| CAN Renewables Limited | Construction | 2020 |
| CAN Structures Limited | Administrative & support | 2003 |
| CAN UK Holdings Limited | Financial services | 2003 |
| Ceetech Limited | Construction | 2001 |
| Central Alliance (Holdings) Limited | Construction | 2014 |
| Central Alliance PRE Construction Services Ltd | Construction | 2006 |
| Cognica Limited | Professional & scientific | 1998 |
| Consents Solutions Ltd | Administrative & support | 2011 |
| Cumbria Access Services Limited | Construction | 1997 |
| CX Energy Ltd | Construction | 2018 |
| CX Group Holdings Limited | Financial services | 2023 |
| CX Utilities Ltd | Professional & scientific | 2015 |
| DWD Property and Planning Limited | Professional & scientific | 2023 |
| E.D.P. Health, Safety and Environment Consultants Limited | Professional & scientific | 1999 |
| Ecologia Environmental Solutions Holdings Limited | Water & waste | 2010 |
| Ecologia Environmental Solutions Limited | Water & waste | 2000 |
| EDP Consultants Ltd | Professional & scientific | 2014 |
| Enviresearch Technologies Limited | Information & communication | 2018 |
| Envirolab Limited | Professional & scientific | 2002 |
| Fluid Sealing & Engineering Limited | Construction | 2017 |
| Geocore Site Investigations Limited | Construction | 2000 |
| Helsby Golf Club Limited | Arts & recreation | 2013 |
| High Voltage Energy Systems Ltd | Extraterritorial | 2026 |
| Hillside Pharma Services Limited | Professional & scientific | 2007 |
| Hollywood Civil Engineering Limited | Administrative & support | 2008 |
| Homestead Cottages Management Company Ltd | Extraterritorial | 2023 |
| HV Energy Systems Ltd | Construction | 2017 |
| Hydrofix Limited | Professional & scientific | 2003 |
| J Elliott Associates Ltd | Professional & scientific | 2003 |
| J.E. Finance Ltd | Financial services | 2014 |
| JB Site Investigations Limited | Construction | 2016 |
| Just Libra Consulting Ltd | Education | 2012 |
| JWS Property Ltd | Construction | 2018 |
| Kendall Kingscott Limited | Professional & scientific | 2002 |
| Kirton Water Treatment Services Limited | Manufacturing | 2013 |
| Leap Environmental Limited | Professional & scientific | 2008 |
| Navitas Engineering Group Ltd. | Administrative & support | 2019 |
| Navitas Engineering Ltd. | Construction | 2012 |
| Occam Consulting Limited | Professional & scientific | 2000 |
| Octavius Infrastructure Ltd. | Construction | 2017 |
| PB Drilling Limited | Construction | 2018 |
| Permarail Limited | Administrative & support | 2002 |
| Primary Care Cheshire CIC | Health & social care | 2011 |
| Proeon Systems Limited | Information & communication | 2004 |
| RDM Automotive Solutions Ltd | Manufacturing | 2024 |
| Reigate Asset Leasing Ltd. | Administrative & support | 2023 |
| Remedx Limited | Construction | 2004 |
| Richard Allitt Associates Limited | Professional & scientific | 1996 |
| Richard Irvin FM Limited | Administrative & support | 2018 |
| ROC Consulting Limited | Professional & scientific | 1995 |
| RSK (Ireland) Limited | Professional & scientific | 2006 |
| RSK Adas Limited | Professional & scientific | 2016 |
| RSK Business Solutions Holdings Limited | Financial services | 2016 |
| RSK Business Solutions Ltd | Information & communication | 2009 |
| RSK Business Solutions Property Limited | Real estate | 2020 |
| RSK Group Limited | Professional & scientific | 1999 |
| RSK Group Trustees Limited | Financial services | 2009 |
| RSK Integrated Waste Solutions Limited | Manufacturing | 2021 |
| RSK Investments (Newcastle) LLP | | 2023 |
| RSK Investments (Wigan) LLP | | 2022 |
| RSK Land & Development Engineering Limited | Professional & scientific | 2003 |
| RSK Middle East Limited | Professional & scientific | 2010 |
| RSK Nature Repair Limited | Professional & scientific | 2024 |
| RSK Newcastle Property LLP | | 2023 |
| RSK Project Services Limited | Professional & scientific | 1994 |
| RSK RAW Limited | Professional & scientific | 2019 |
| RSK Stats Environment Health and Safety Limited | Professional & scientific | 2003 |
| RSK Stats Geoconsult Limited | Construction | 1991 |
| RSK Wigan Property LLP | | 2020 |
| Rskw Ltd | Professional & scientific | 2008 |
| SES Strategic Limited | Administrative & support | 2014 |
| Singleton Clamp & Partners Limited | Professional & scientific | 1999 |
| Structural Soils Limited | Construction | 1964 |
| Sustainable Aquafarms Limited | Agriculture & fishing | 2019 |
| Talkabout Publishing Limited | Information & communication | 2009 |
| TBF Scaffolding Ltd | Construction | 1984 |
| TBF Traffic Ltd | Construction | 2003 |