| J L Darling & Sons Ltd | Construction | 2007 |
| J Lens Ltd | Professional & scientific | 2020 |
| J N Lane Associates Limited | Professional & scientific | 2000 |
| J N Lane Associates Surveyors Limited | Professional & scientific | 2020 |
| J P Lewis Electrics Ltd | Construction | 2021 |
| J&C Digital Ltd | Professional & scientific | 2023 |
| J&P Pharma UK Limited | Professional & scientific | 2004 |
| J&S Capital Management Ltd | Financial services | 2014 |
| J.E. Darling & Sons Limited | Construction | 1993 |
| J.F.E.Investments(Weybridge)Limited | Construction | 1965 |
| J.P. Cleaning Services Limited | Administrative & support | 2001 |
| Jack Services Limited | Administrative & support | 2009 |
| Jackdaw Menswear Ltd | Wholesale & retail | 2016 |
| Jacksonspindles Ltd | Real estate | 2025 |
| Jacques and Jacques Limited | Administrative & support | 2025 |
| Jake Spencer Ltd | Administrative & support | 2001 |
| James B Langley Ltd | Other services | 2003 |
| James Brabner & Company Limited | Wholesale & retail | 1963 |
| James Brown & Associates Limited | Other services | 2018 |
| James Cura Studio Ltd | Professional & scientific | 2022 |
| James Daly Ltd | Information & communication | 2016 |
| James Hallam Limited | Financial services | 1982 |
| James Knapp Limited | Professional & scientific | 2013 |
| James L Morrone Ltd | Administrative & support | 2016 |
| James Nicholson Marketing Ltd | Information & communication | 2019 |
| James Nicholson Training Services Ltd | Information & communication | 2023 |
| James Pike Photography Limited | Professional & scientific | 2002 |
| James Vellacott Associates Ltd | Information & communication | 2026 |
| Janas Limited | Real estate | 1993 |
| Janebcreatives Limited | Professional & scientific | 2008 |
| Jannard Quadrant Insurance Brokers Limited | Financial services | 1999 |
| Jaques Construction Ltd | Construction | 2000 |
| JAW Brokers Ltd | Construction | 2025 |
| Jaxon CHE Property Limited | Real estate | 2018 |
| JAY James Miller Ltd | Information & communication | 2023 |
| Jaycorn Limited | Wholesale & retail | 2012 |
| Jayes Energy Ltd | Energy | 2011 |
| Jayes Estate Developments Limited | Real estate | 1969 |
| Jayes Estate Nominees NO 1 Ltd | Financial services | 2024 |
| Jayes Estate Nominees NO 2 Ltd | Financial services | 2023 |
| Jayes Farms Limited | Agriculture & fishing | 1991 |
| Jcbr Ltd | Administrative & support | 2025 |
| JCH General Management Limited | Arts & recreation | 2018 |
| Jcjoy Ltd | Health & social care | 2021 |
| JD IT Services Limited | Information & communication | 2009 |
| JE Consulting Services Limited | Professional & scientific | 2023 |
| JE Media Limited | Professional & scientific | 2024 |
| Jefferson Court (Redhill) Management Company Limited | Households | 1977 |
| JES Consultants Limited | Arts & recreation | 2015 |
| JFL Rental Units Ltd | Real estate | 2024 |
| JGP Plastering & Brickwork Ltd | Construction | 2020 |
| JH Lifestyle Ltd | Health & social care | 2024 |
| Jimmy D Trading Ltd | Construction | 2022 |
| JJ Property Investments (London) Ltd | Real estate | 2022 |
| Jj's Kitchen and Catering Limited | Hospitality | 2026 |
| Jjcm Management Limited | Real estate | 2023 |
| JL Design Ltd | Arts & recreation | 2022 |
| JLZ Abreu Asset Group Ltd | Real estate | 2026 |
| Jmcs Services Limited | Construction | 2018 |
| Jmob Services Ltd | Information & communication | 2018 |
| JMT Boardrooms Limited | Professional & scientific | 2010 |
| JMT Canines Limited | Other services | 2021 |
| Joanna Hill Enterprises Limited | Health & social care | 2023 |
| Jobit Solutions Limited | Information & communication | 2024 |
| JOE Mellows Limited | Professional & scientific | 2011 |
| JOE Sowton Consulting Limited | Professional & scientific | 2025 |
| John Calvert Design Ltd | Professional & scientific | 2010 |
| John Field Fundraising Ltd | Professional & scientific | 2020 |
| Johnson Construction & Building Ltd | Construction | 2010 |
| JON Harding Associates Limited | Administrative & support | 2016 |
| Jonathan Blair Associates Ltd | Financial services | 2024 |
| Jonathan Mayo Media Limited | Information & communication | 2017 |
| Jonita Limited | Agriculture & fishing | 1992 |
| Jordan Party Wall Surveyors Ltd | Construction | 2011 |
| Joshua House (Shepperton) Management Company Limited | Households | 2015 |
| JR Consult & Connect Ltd | Professional & scientific | 2021 |
| JRC Regency Ltd | Professional & scientific | 2025 |
| JS Clothing Limited | Wholesale & retail | 2025 |
| JS Digital Associates Limited | Information & communication | 2022 |
| JSW Design Ltd | Arts & recreation | 2011 |
| Junction Mews Ltd | Real estate | 2012 |
| Juniors Enterprises Ltd | Professional & scientific | 2020 |
| Juno Makes Limited | Professional & scientific | 2022 |
| Just About Flooring Ltd | Construction | 2026 |
| Just Champagne Limited | Wholesale & retail | 1998 |
| Just Extensions (Holdings) Limited | Real estate | 2021 |
| Just Extensions (Reigate) Limited | Construction | 2009 |
| Justice Wiseman Ltd | Professional & scientific | 2026 |
| JVJ Solutions Limited | Information & communication | 2015 |
| JW Equine and Farm Supplies Ltd | Wholesale & retail | 2025 |
| JYO Ltd | Construction | 2021 |
| K & M Decorating Services Limited | Construction | 2002 |
| K Samy Enterprises Ltd | Wholesale & retail | 2025 |
| K.O.C.A Community Projects CIC | Arts & recreation | 2020 |
| K3 Fight & Fitness Academy Ltd | Education | 2022 |
| Kahle Limited | Wholesale & retail | 2026 |
| Kaizen Ozen Ltd | Real estate | 2024 |
| Kalasin Events Ltd | Hospitality | 2023 |
| Kamila Gutowska Limited | Hospitality | 2016 |
| Kanoco Limited | Manufacturing | 2024 |