| Lions Pier Limited | Hospitality | 2015 |
| Lipa's Lounge Ltd | Hospitality | 2025 |
| Lisee House RTM Company Ltd | Households | 2022 |
| Lishi Commercial Development LLP | | 2024 |
| Lishida Care Ltd | Health & social care | 2022 |
| Lishifa Estate Company Ltd | Real estate | 2022 |
| Lister Aesthetics Ltd | Other services | 2025 |
| Litepro Lighting (UK) Limited | Professional & scientific | 2018 |
| Little Acorns (Eastbourne) Ltd | Health & social care | 2009 |
| Little Acorns EMI LLP | | 2009 |
| Little Chelsea Creative Ltd | Professional & scientific | 2011 |
| Little Chelsea Flower Co Limited | Wholesale & retail | 2023 |
| Little Chelsea Interiors Ltd | Manufacturing | 2025 |
| Little Chelsea Property Management Limited | Households | 2012 |
| Little Italy (Eastbourne) Limited | Hospitality | 2011 |
| Little JS Limited | Education | 2011 |
| Little Madeira Cafe Ltd | Wholesale & retail | 2024 |
| Little Rockets Limited | Education | 2010 |
| Little Sprouts Garden CIC | Health & social care | 2025 |
| Little Worsham Barns Limited | Construction | 2022 |
| Little Zack Locations Ltd | Information & communication | 2014 |
| Littlecote Management Limited | Households | 1985 |
| Littletoe Limited | Administrative & support | 2010 |
| Live SEC Ltd | Administrative & support | 2021 |
| Living Hope Smart Care Limited | Health & social care | 2026 |
| Living Life (Eastbourne) | Health & social care | 2005 |
| Living Matters Ltd | Professional & scientific | 2012 |
| Living Medicine | Education | 2004 |
| Living Spaces Development Ltd | Real estate | 2024 |
| Living Stones, Eastbourne | Other services | 2003 |
| Livtom Limited | Health & social care | 2023 |
| LIZ O'Higgins Orthodontics Limited | Health & social care | 2021 |
| Lizphil Restaurants Ltd | Hospitality | 2016 |
| LJ Homes Ltd | Real estate | 2024 |
| LJ Jarvie Ltd | Health & social care | 2024 |
| LJB LEE Botting Limited | Construction | 2001 |
| LJB Motors (South East) Limited | Wholesale & retail | 2024 |
| LJK London Limited | Other services | 2023 |
| LJM Productions Ltd | Professional & scientific | 2025 |
| Ljpreston Ltd | Health & social care | 2023 |
| LJS Barbers Brighton Limited | Real estate | 2025 |
| LJT Carpentry Ltd | Construction | 2025 |
| LJU Limited | Professional & scientific | 2020 |
| LKJ Restaurants Ltd | Hospitality | 2025 |
| LKM Construction Ltd | Construction | 2020 |
| Lloyd Savage Property Limited | Real estate | 2017 |
| LM Productions Limited | Administrative & support | 1989 |
| LM Projects Limited | Construction | 2011 |
| Lmaats Limited | Professional & scientific | 2023 |
| Lmautoparts Limited | Wholesale & retail | 2025 |
| Lmdb Limited | Professional & scientific | 2006 |
| Lmdb Payroll LLP | | 2013 |
| LMG Jewellery Limited | Administrative & support | 1999 |
| Lmjb Group Limited | Health & social care | 2022 |
| LMT Homes Limited | Real estate | 2025 |
| LN2 Technologies Ltd | Information & communication | 2025 |
| LNL Ltd | Transport & logistics | 2023 |
| LNV Dental Limited | Health & social care | 2023 |
| Loads of Travel Ltd | Administrative & support | 2024 |
| Loca-Motion Limited | Arts & recreation | 1999 |
| Locke Technology Limited | Information & communication | 2025 |
| Lockinex (UK) Ltd. | Wholesale & retail | 2001 |
| Lockwood 21 Limited | Real estate | 2013 |
| Lockwood Entertainment Limited | Professional & scientific | 2019 |
| Lodestone Financial Planning Ltd. | Financial services | 2012 |
| Lodge and Lounge Ltd | Real estate | 2022 |
| Lodoss Energy Limited | Professional & scientific | 2026 |
| Loft Direct Limited | Real estate | 2023 |
| Loft Direct Property Management Ltd | Real estate | 2023 |
| Loft Invaders Ltd | Construction | 2024 |
| Logilumber Ltd | Manufacturing | 2025 |
| Logistic Solutions South East Limited | Transport & logistics | 2019 |
| Lola's Pet Products Limited | Wholesale & retail | 2019 |
| Londinium Acquisition & Investment Limited | Real estate | 2015 |
| London & South East GAS Service Company Ltd | Construction | 2019 |
| London Ballroom Events Ltd | Arts & recreation | 2022 |
| London Bridge Academy Ltd | Education | 2026 |
| London Bridge Imaging Limited | Health & social care | 2013 |
| London Commissioning Services Limited | Construction | 2014 |
| London Delight Ltd | Wholesale & retail | 2023 |
| London Dentistry Training Ltd | Education | 2019 |
| London Development Events Limited | Professional & scientific | 2006 |
| London Education and Training Links Limited | Extraterritorial | 2007 |
| London Party Decor Ltd | Hospitality | 2021 |
| London Scraps V Ltd | Water & waste | 2011 |
| Long Arrow Ltd | Professional & scientific | 2026 |
| Long Island Mews Consulting Ltd | Professional & scientific | 2017 |
| Longboat Consultancy Limited | Financial services | 2021 |
| Longdean Capital LLP | | 2018 |
| Longhurst Consulting Ltd | Professional & scientific | 2018 |
| Longleaf Sussex Limited | Wholesale & retail | 2020 |
| Longman Home Interiors Ltd | Wholesale & retail | 2021 |
| Longmore Periodontics Limited | Health & social care | 2024 |
| Longsight Management and Logistics Limited | Professional & scientific | 2005 |
| Lonsdale Investment Limited | Financial services | 2002 |
| Lonson Construction Ltd | Construction | 2024 |
| Lookalikes Sussex Limited | Arts & recreation | 2023 |
| Lopes DOS Santos Ltd | Hospitality | 2024 |
| Lord Street Capital Limited | Real estate | 2022 |
| Lorna K Hair Limited | Other services | 2025 |