| Harris Real Estate Group Ltd | Real estate | 2025 |
| Hatherley 1960 Limited | Extraterritorial | 2013 |
| Haystack Rock Limited | Information & communication | 2011 |
| HCL Business Services Ltd. | Professional & scientific | 2012 |
| Health Property Solutions Limited | Households | 2013 |
| Healthqube Ltd | Wholesale & retail | 2023 |
| Healthy Care Services Ltd | Health & social care | 2023 |
| Hemp Gold Solutions Ltd | Wholesale & retail | 2023 |
| Henry Taylor Transport Limited | Transport & logistics | 2017 |
| HER Comeback Club Ltd | Administrative & support | 2026 |
| Heritage Property Care Limited | Administrative & support | 2012 |
| Hetherington Roofing Limited | Construction | 2019 |
| High Street Great Missenden (Property Management) Company Limited | Households | 2002 |
| Highlow Limited | Hospitality | 2016 |
| HIP2KNEE Clinic Limited | Health & social care | 2014 |
| Historic Motor Racing News Limited | Administrative & support | 2000 |
| Historic Motorsport Network Ltd | Administrative & support | 2024 |
| HMG Associates Limited | Professional & scientific | 2008 |
| Hohoco Ltd | Information & communication | 2017 |
| Homesite Group C.I.C. | Administrative & support | 2023 |
| Horse and Hounds Launderette Ltd | Administrative & support | 2018 |
| Hudson Lucas Ltd | Extraterritorial | 2014 |
| HXZ Consultancy & Coaching Limited | Information & communication | 2024 |
| Idlicote Park Management Company Limited | Households | 2025 |
| Igrs Soft Limited | Information & communication | 2018 |
| Ilford Building Company Limited | Real estate | 1932 |
| Inspired 4 Learning Limited | Professional & scientific | 2011 |
| Instrategy Limited | Information & communication | 2015 |
| Intelligent Metrix Limited | Information & communication | 2009 |
| Itopia Properties Limited | Real estate | 2021 |
| IWS Homes Ltd | Real estate | 2023 |
| J a K B Limited | Information & communication | 2008 |
| J S Stonemasonry Ltd | Manufacturing | 2011 |
| J. Walker & SON (Agriculture) Limited | Agriculture & fishing | 2017 |
| J. Walker & SON (Investment Holdings) Limited | Real estate | 2019 |
| J. Walker & SON (Investments) Limited | Real estate | 1950 |
| J.W.R.A. Limited | Other services | 1999 |
| J.Walker & SON (Development) Limited | Construction | 2017 |
| JAI Holdings Limited | Real estate | 2015 |
| Jamestead Construction Limited | Construction | 1986 |
| Jatinder Holdings LLP | | 2016 |
| JDN Plastering Limited | Construction | 2016 |
| Jerome Services (Nursing) Limited | Transport & logistics | 2021 |
| John Spooner Ltd | Transport & logistics | 2025 |
| JRO Consultancy Services Limited | Administrative & support | 2022 |
| JRO Holdings Limited | Financial services | 2017 |
| JRO Properties Limited | Real estate | 2018 |
| Juky Props Ltd | Information & communication | 2021 |
| Julespilates.Gym Ltd | Arts & recreation | 2024 |
| Jumbo Trading Limited | Wholesale & retail | 2018 |
| Kadland Capital Group Limited | Financial services | 2023 |
| KAN9 Solutions Ltd | Health & social care | 2023 |
| Kenny D Consultant Ltd | Mining & quarrying | 2025 |
| Kentwell Properties Ltd | Real estate | 2013 |
| KEY2INVESTING Limited | Financial services | 2017 |
| Khan & Jackson Developments Ltd | Real estate | 2022 |
| Kingscote Consultancy Limited | Administrative & support | 2022 |
| Kingsforth Developments Limited | Construction | 2019 |
| Kingsforth Group Limited | Real estate | 2019 |
| Kitchen Co-Ordination Limited | Wholesale & retail | 2003 |
| KNR Holdings Ltd | Real estate | 2018 |
| Kolling Carpentry Ltd | Construction | 2025 |
| Landmaze Limited | Construction | 1999 |
| Laser Learning Limited | Education | 2009 |
| Laura Bailey Ltd | Administrative & support | 2025 |
| Laura-Jo Barge Ltd | Manufacturing | 2023 |
| Lawsons Accountants Limited | Professional & scientific | 2008 |
| Lazysoft Limited | Information & communication | 2003 |
| LE COQ Epicier Limited | Wholesale & retail | 2015 |
| Leadership Focus Limited | Education | 2017 |
| Lelk Limited | Real estate | 2022 |
| Letsgomovers Ltd | Transport & logistics | 2024 |
| Libra Sun Ltd | Wholesale & retail | 2020 |
| Lions PDC 1 Limited | Real estate | 2017 |
| Lisa Accountz Ltd | Professional & scientific | 2023 |
| Litelime Ltd | Information & communication | 2009 |
| Little Chalfont Food & Wine Limited | Wholesale & retail | 2023 |
| Little Express Limited | Wholesale & retail | 2024 |
| Little Retreat Limited | Other services | 2012 |
| Live Without Limits Ltd | Construction | 2018 |
| Lodge Farm Management Limited | Real estate | 2020 |
| Loft Hatch Consultancy Limited | Professional & scientific | 2025 |
| Lomas IT Ltd | Information & communication | 2019 |
| Lost and Found Properties Ltd | Construction | 2024 |
| Loudhams Wood Lane Management Company Limited | Households | 1997 |
| Louise Cruttenden Consulting Ltd | Administrative & support | 2021 |
| M Chick Plumbing and Heating Limited | Construction | 2019 |
| M. G. T. Design Engineers Limited | Professional & scientific | 1996 |
| Majithia ENT Consultancy Limited | Health & social care | 2013 |
| Mananthra Properties Limited | Real estate | 2024 |
| Marcello Properties Limited | Real estate | 1976 |
| Mark Pointon Limited | Other services | 2002 |
| Mas&Or Limited | Administrative & support | 2024 |
| Maybourne Developers Limited | Real estate | 2003 |
| Medicsys UK Limited | Real estate | 2009 |
| Melissa Maynard Heritage Ltd | Other services | 2021 |
| Mellody Services Limited | Information & communication | 2022 |
| Mesar Ltd | Financial services | 2021 |
| Metacella Limited | Professional & scientific | 2012 |
| Metal Window Solutions Ltd | Construction | 2024 |