| LE Brun House Limited | Health & social care | 2016 |
| LE Poujol Limited | Health & social care | 2021 |
| LEA House Residents Eastbourne Limited | Households | 1993 |
| Leaden Hill (Coulsdon) Management Company Limited | Households | 2017 |
| Leader Property Management Ltd | Hospitality | 2025 |
| Leader's Engineering and Environmental Services Limited | Water & waste | 2008 |
| Leading Edge Exhibits Limited | Administrative & support | 1999 |
| Leadstone Park OP Limited | Professional & scientific | 2024 |
| Leadstone Park Opsh Limited | Professional & scientific | 2024 |
| Leaf Testing Ltd | Professional & scientific | 2021 |
| Leafyit Ltd | Wholesale & retail | 2024 |
| Leah Langley Limited | Wholesale & retail | 2023 |
| Leahurst Management RTM Company Limited | Households | 2018 |
| Lean Air Limited | Manufacturing | 2016 |
| Leanx Solutions Ltd | Information & communication | 2020 |
| Leaps & Bounds Limited | Administrative & support | 2009 |
| Leather on Willow Ltd | Wholesale & retail | 2020 |
| Lecs (UK) Ltd | Professional & scientific | 1991 |
| Led-Uk Lighting Limited | Wholesale & retail | 2016 |
| Ledbury Dental Care Ltd | Health & social care | 2013 |
| LEE Mead Productions Limited | Arts & recreation | 2007 |
| Leea Foods Ltd | Hospitality | 2022 |
| Leeding Properties Limited | Real estate | 2019 |
| Lefactory Ltd | Manufacturing | 2023 |
| Left Foot Braking Limited | Financial services | 2008 |
| Legacy Creator Network Ltd | Wholesale & retail | 2025 |
| Legal Pandas Ltd | Information & communication | 2019 |
| Legal Technology Ventures Ltd | Information & communication | 2021 |
| Legend Health Care Solutions Limited | Health & social care | 2025 |
| Legin Property LLP | | 2006 |
| Leidar UK Ltd | Professional & scientific | 2018 |
| Leisure Leagues Sussex Ltd | Arts & recreation | 2023 |
| Lemon Tree Media Ltd | Information & communication | 2024 |
| Lemonade From Lemons Community Interest Company | Health & social care | 2024 |
| Lemonade Money Clubs Limited | Hospitality | 2018 |
| Lennox Construction Limited | Construction | 2008 |
| Leomhann Capital Limited | Financial services | 2016 |
| Leon Jenner and SON Limited | Construction | 2015 |
| Lepere Analytics Limited | Administrative & support | 2005 |
| Leppards Butchers Ltd | Extraterritorial | 2016 |
| LES Pepites Limited | Wholesale & retail | 2024 |
| Leslie Salons Limited | Other services | 1998 |
| LET Fred Limited | Real estate | 2019 |
| Let’S Go Property Rental & Property Management Ltd | Real estate | 2024 |
| Levels Bottle Shop Limited | Wholesale & retail | 2018 |
| Levett Holdings Ltd | Professional & scientific | 2005 |
| Levett Properties Limited | Real estate | 2018 |
| Leway Services Limited | Wholesale & retail | 2023 |
| Lewes Foods and Vegetables Limited | Wholesale & retail | 2018 |
| Lewes Medical Chambers Limited | Health & social care | 2026 |
| Lewes Roofing Ltd | Construction | 2025 |
| Lewes Roofing Services Ltd | Construction | 2016 |
| Lewes RS Ltd | Arts & recreation | 2026 |
| Lewis Kingsnorth Ltd | Health & social care | 2011 |
| Lewus Studio Limited | Information & communication | 2022 |
| Leybourne House (SE) Limited | Health & social care | 2024 |
| Leyland Technical Services Ltd | Other services | 2022 |
| Leylu Ltd | Real estate | 2026 |
| Leyton Calling Ltd | Hospitality | 2024 |
| LFK Dental Ltd | Health & social care | 2025 |
| LFL Clover Ltd | Wholesale & retail | 2024 |
| LGM Futures Limited | Real estate | 2024 |
| LGS Properties Ltd | Real estate | 1998 |
| LH Electrical (South East) Limited | Construction | 2021 |
| Liadent Limited | Health & social care | 2018 |
| Liam Gallagher Ltd | Manufacturing | 2002 |
| Liam Kilby Limited | Information & communication | 2025 |
| Libero Consulting Group Ltd | Professional & scientific | 2024 |
| Libyans Connect CIC | Health & social care | 2024 |
| Lidice Ltd | Households | 2019 |
| Life AID Project CIC | Information & communication | 2025 |
| Life Science Access Academy Limited | Professional & scientific | 2019 |
| Life's Little Luxuries Limited | Wholesale & retail | 2016 |
| Liftlash Limited | Wholesale & retail | 2013 |
| Light Bar Holdings Limited | Hospitality | 2021 |
| Light Bar Shoreditch Ltd | Hospitality | 2020 |
| Lightfoot House Limited | Financial services | 2009 |
| Lighthouse Projects (Sussex) Limited | Construction | 2024 |
| Lighthouse Therapeutics Limited | Manufacturing | 2023 |
| Like a Prayer Limited | Hospitality | 2023 |
| Lilibird Limited | Hospitality | 2005 |
| Lilly Property Developments Ltd | Construction | 2025 |
| Lilly Property Investments Ltd | Real estate | 2025 |
| Lily Care Services Ltd | Health & social care | 2015 |
| Lily Nguyen 68 Ltd | Other services | 2025 |
| Lilybridge Investments Limited | Administrative & support | 2006 |
| Lima Property Ltd | Real estate | 2025 |
| Lin's UK Ltd | Administrative & support | 2016 |
| Lincoln Jaeger Limited | Arts & recreation | 2018 |
| Lincoln Partners Limited | Administrative & support | 2010 |
| Lindeck Limited | Construction | 2013 |
| Linden Services Limited | Hospitality | 2025 |
| Lindokuhle Ltd | Real estate | 2023 |
| Lindon East LLP | | 2010 |
| Linguista.Com Ltd | Administrative & support | 2013 |
| Link-Uk Property Management Limited | Real estate | 2020 |
| Linklark Estates Limited | Real estate | 2024 |
| Links Agents Limited | Financial services | 2013 |
| Links Mead Management Company Limited | Households | 2000 |
| Linkswood (Eastbourne) Management Company Limited | Households | 2004 |