| Kudu Medical Limited | Professional & scientific | 2009 |
| Kurt Construction International Limited | Construction | 2015 |
| Kurt Systems (UK) Limited | Agriculture & fishing | 2012 |
| KW (Site B) Management Company Limited | Households | 2016 |
| KW Rendering & Repointing Limited | Construction | 2022 |
| L RAE Creative Ltd | Wholesale & retail | 2024 |
| L Stuart-Kregor Consulting Ltd | Professional & scientific | 2023 |
| L.J. Smith & Co. Limited | Real estate | 1988 |
| LA Cinquecento Ltd | Manufacturing | 2025 |
| LA Dolce Vita Coaching & Consulting Ltd | Other services | 2017 |
| Lake Autosnug Ltd | Transport & logistics | 2011 |
| Lambourn Chase Management Limited | Households | 2006 |
| Lambourn Foodhall Ltd | Hospitality | 2021 |
| Lambourn Garage Limited | Wholesale & retail | 2015 |
| Lambourn Junction Community Interest Company | Health & social care | 2021 |
| Lambourn Racehorse Transport Limited | Transport & logistics | 1991 |
| Lambourn RDA Incorporating Carriage Driving Limited | Arts & recreation | 2011 |
| Lambridge Wood Barn Limited | Hospitality | 2025 |
| Lamore BV Limited | Hospitality | 2022 |
| Landmark Weybridge Limited | Real estate | 2021 |
| Lane's Horticultural Ltd | Agriculture & fishing | 2021 |
| Langley Property Group Limited | Real estate | 2021 |
| Langley Property Services (Berkshire) Limited | Real estate | 2018 |
| Langley Steel Limited | Wholesale & retail | 2020 |
| Laura Fishlock Osteopathy Hungerford Ltd | Health & social care | 2022 |
| Laurels Residents Association (Hungerford) Limited | Households | 1978 |
| Lawrence Establishment Limited | Real estate | 2025 |
| Layers Hair Design Limited | Other services | 2014 |
| Laylands Green 1972 Limited | Extraterritorial | 2014 |
| LBV Technology Services Limited | Professional & scientific | 2024 |
| LC ENG Limited | Professional & scientific | 2007 |
| LD Collectables Ltd | Arts & recreation | 2026 |
| LEE Davies Building & Groundwork Limited | Construction | 2014 |
| Legend Consultancy Limited | Professional & scientific | 1998 |
| Legends Barbers (Newbury) Ltd | Other services | 2018 |
| Lemon PIP Consulting Limited | Professional & scientific | 2008 |
| LEO & Blake Limited | Wholesale & retail | 2024 |
| Leoace Limited | Real estate | 1992 |
| Leopard Gins Limited | Manufacturing | 2025 |
| Level UP Newbury Limited | Construction | 2022 |
| Lewis Electrical (Newbury) Limited | Construction | 1997 |
| Lewis Renovations Ltd | Construction | 2020 |
| LIA Group Holdings Ltd | Financial services | 2021 |
| LIA International Limited | Other services | 2001 |
| Liansolutions Ltd | Information & communication | 2017 |
| Lighting for Events Limited | Professional & scientific | 2015 |
| LK Mechanical Services Ltd | Construction | 2025 |
| Loam Coffee Limited | Wholesale & retail | 2022 |
| Lochrane Associates Limited | Professional & scientific | 2012 |
| Lock & Key Direct Limited | Extraterritorial | 2023 |
| Locksbridge Park (Andover) Management Company Limited | Households | 2014 |
| Londinium Travel Limited | Transport & logistics | 2014 |
| London Velvet Ltd | Wholesale & retail | 2015 |
| Long Close Management Co. Ltd. | Professional & scientific | 2004 |
| Long Game Training Ltd | Arts & recreation | 2020 |
| Longfield Lands Limited | Real estate | 1998 |
| Lottimo Ltd | Other services | 2012 |
| Lozowsky Ltd | Manufacturing | 2022 |
| LS Composites Ltd | Manufacturing | 2017 |
| LTH Flooring Limited | Wholesale & retail | 2020 |
| LTH Luxury Lodgings Limited | Real estate | 2025 |
| Lucy Watson Productions Limited | Professional & scientific | 2013 |
| Ludlow Art Consultancy Limited | Professional & scientific | 2025 |
| Ludlow Ventures Ltd | Professional & scientific | 2025 |
| Lunca Dunarii Ltd | Wholesale & retail | 2016 |
| Lynleven Investments Limited | Real estate | 2017 |
| M & P (Newton Abbot) Management Limited | Households | 2008 |
| M & P Hardware Hungerford Limited | Wholesale & retail | 2013 |
| M B Brickwork Contractors Limited | Construction | 2007 |
| M Feltham Building and Carpentry Limited | Construction | 2024 |
| M-Squared Quantity Surveying Services Limited | Other services | 2011 |
| MACH2 Solutions Limited | Financial services | 2019 |
| Macklin Construction Ltd | Construction | 2018 |
| Maidenhead 3S Ltd | Arts & recreation | 2024 |
| Main Marine Limited | Agriculture & fishing | 2025 |
| Majesta Travel Limited | Administrative & support | 2023 |
| MAM Software Limited | Information & communication | 1984 |
| Management Services (Estates) Limited | Administrative & support | 1982 |
| Mancey Interiors & Soft Furnishings Ltd | Professional & scientific | 2013 |
| Mandrake Properties Limited | Real estate | 1997 |
| Manton Capital Ltd | Financial services | 2025 |
| Manton Property Ltd | Construction | 2016 |
| Manton Protect Ltd | Administrative & support | 2020 |
| Maple Plumbing and Heating Ltd | Construction | 2022 |
| Mark Day Designs Ltd | Professional & scientific | 2020 |
| Mark Humphreys Associates Limited | Professional & scientific | 2021 |
| Mark James Energy Ltd | Professional & scientific | 2021 |
| Mark Usher Racing Limited | Arts & recreation | 2014 |
| Marketplace Family Mart Ltd | Wholesale & retail | 2021 |
| Marlborough Law Limited | Professional & scientific | 2017 |
| Marlston Consultancy Limited | Other services | 2001 |
| Marmalade Furniture and Joinery Limited | Manufacturing | 2017 |
| Marshview Enterprises Limited | Real estate | 2011 |
| Martin & the Magpie Limited | Wholesale & retail | 2017 |
| Martin Collins Enterprises (Holdings) Limited | Construction | 1984 |
| Martin Collins Enterprises Limited | Administrative & support | 1998 |
| Marwell Horse Transport Limited | Agriculture & fishing | 2021 |
| Marwell Thoroughbreds Limited | Agriculture & fishing | 2000 |
| Mary Maggs Ltd | Wholesale & retail | 2012 |
| Matrix Precision Engineering Limited | Manufacturing | 2004 |