| Klaver Energy Consulting Limited | Professional & scientific | 2012 |
| KLE Ltd | Information & communication | 2017 |
| KLT Enterprises Limited | Financial services | 1990 |
| Kmls Ltd | Real estate | 2024 |
| Knightsbridge Medical Aesthetic Limited | Professional & scientific | 2024 |
| Knottberry Ltd | Wholesale & retail | 2015 |
| Knowdle AI Financial Technologies Accelerator Ltd | Information & communication | 2023 |
| Knowdle Worldwide Ltd | Information & communication | 2018 |
| KOI Consulting Partners Limited | Health & social care | 2006 |
| Komu Projects Ltd | Construction | 2023 |
| Kondor Kidz Ltd | Wholesale & retail | 2022 |
| Kool Zone Limited | Manufacturing | 2015 |
| Kris Love Ltd | Information & communication | 2017 |
| KSA Learning Limited | Professional & scientific | 2004 |
| KSK Henley Food & Wine Ltd | Wholesale & retail | 2025 |
| Kuba & Leia Limited | Wholesale & retail | 2017 |
| Kuzzy Group Ltd | Hospitality | 2022 |
| KVB Build & Interiors Ltd | Construction | 2013 |
| KVB Design Limited | Administrative & support | 2004 |
| L D School Ltd | Education | 2016 |
| L.H.W. Properties Ltd | Real estate | 1949 |
| Lagma Ltd | Professional & scientific | 2017 |
| LAM Invest Limited | Financial services | 2023 |
| Lamorna Management Limited | Households | 1986 |
| Langtree Sinfonia Productions Ltd | Arts & recreation | 2023 |
| Lanow Limited | Professional & scientific | 2019 |
| Lapis Business Services Limited | Professional & scientific | 2018 |
| Larch Close Management Limited | Households | 2014 |
| Lastshaw Limited | Real estate | 1979 |
| Lauk Planning Limited | Administrative & support | 2018 |
| Laumex Ltd | Wholesale & retail | 2017 |
| Launchpad Consultants Ltd | Information & communication | 2019 |
| Lavanda Ltd | Extraterritorial | 2013 |
| Ldfilmconstruction Limited | Construction | 2022 |
| Leander Club Limited | Arts & recreation | 2016 |
| Leander Investment Partners Limited | Financial services | 2021 |
| Learn to Talk Dog Limited | Wholesale & retail | 2014 |
| Lecxie Ltd | Professional & scientific | 2025 |
| LEE Hewitt Limited | Other services | 2010 |
| Leisure Projects Limited | Construction | 2022 |
| Leisureworks Studio Limited | Manufacturing | 2022 |
| LES Jardins D'Olivier Limited | Construction | 2012 |
| Lgateservices Ltd | Professional & scientific | 2026 |
| Lightning Commercial Finance Limited | Financial services | 2018 |
| Lily MAE Jack Investments Limited | Real estate | 2014 |
| Lime Court Management (Henley) Limited | Households | 2011 |
| Limelight Consulting Limited | Administrative & support | 2017 |
| Lindsay Blee & Co. Limited | Wholesale & retail | 1959 |
| Lindsay Blee Limited | Financial services | 2009 |
| Lindsey Lang Design Ltd | Professional & scientific | 2012 |
| Line & Signal Limited | Professional & scientific | 2025 |
| Liongate Advisory Limited | Professional & scientific | 2026 |
| Lithergrange Limited | Wholesale & retail | 1972 |
| Little Angel PUB Company Ltd | Hospitality | 2022 |
| LJ Property Consultancy Ltd | Real estate | 2023 |
| LJM Electrical Limited | Construction | 2013 |
| LMS Advisory Services Ltd | Professional & scientific | 2025 |
| Local Quotes Limited | Information & communication | 2026 |
| Locheden Limited | Financial services | 2016 |
| Lockend Services Limited | Professional & scientific | 2019 |
| Lockforce (UK) Ltd | Administrative & support | 2013 |
| Loddon Limited | Financial services | 2024 |
| Loggie Bear Customs Limited | Wholesale & retail | 2025 |
| London Commercial Investments Limited | Real estate | 1951 |
| London European Securities Limited | Financial services | 2016 |
| London Street Brasserie Limited | Hospitality | 1999 |
| Longcot View (Shrivenham) Management Company Limited | Real estate | 2017 |
| Longreach Entertainment & Media Limited | Information & communication | 2023 |
| Longview Services Europe Limited | Professional & scientific | 2014 |
| Loughridge Booth Enterprises Ltd | Health & social care | 2020 |
| Louise Parker Limited | Arts & recreation | 2007 |
| Louise Parker Services Ltd | Other services | 2016 |
| Love Fitness (MA) Ltd | Administrative & support | 2021 |
| Lovibond's Brewery Ltd | Manufacturing | 2005 |
| Ltrs Estates Limited | Hospitality | 2010 |
| Lucas Jones Writing Limited | Information & communication | 2019 |
| Lucca Studios Ltd | Other services | 2024 |
| Lucknam Newbould Key Ltd | Extraterritorial | 2014 |
| Lucky LLC Limited | Professional & scientific | 2024 |
| Lucy Sheikh Consulting Ltd | Professional & scientific | 2016 |
| Lumine Advisors Limited | Professional & scientific | 2026 |
| Luscombe's Limited | Hospitality | 1997 |
| Lyegrove Studios Limited | Professional & scientific | 2026 |
| M & M Property Development Ltd | Construction | 2014 |
| M.A.T. Davies Holdings Limited | Hospitality | 1993 |
| MA Motor South Ltd | Wholesale & retail | 2025 |
| MAC-2 Grip Services Limited | Professional & scientific | 1998 |
| Mach 12 Limited | Information & communication | 2015 |
| Made by Jess Ltd | Professional & scientific | 2018 |
| Magnificent Group Ltd | Professional & scientific | 2016 |
| Maidenhead Glazing & Window Centre Limited | Professional & scientific | 2015 |
| Maidensgrove Investments (Pellgate) Ltd | Real estate | 2026 |
| Maidensgrove Investments (Sheerwater) Ltd | Construction | 2025 |
| Maidensgrove Investments Ltd | Real estate | 2023 |
| Make Henley Shine Limited | Arts & recreation | 2022 |
| Malthouse Management (Henley) Limited | Households | 2006 |
| MAN V Mountain Limited | Wholesale & retail | 2021 |
| Management Performance Limited | Information & communication | 1985 |
| Manara Infra-Tech Global Ltd | Construction | 2025 |
| Manor MIX Concrete Limited | Manufacturing | 2008 |