| Lioness Sport Ltd | Arts & recreation | 2019 |
| Lionfish Properties Ltd | Real estate | 2011 |
| Lionrock Construction Management Ltd | Construction | 2020 |
| Liotru Cleaning Brighton Ltd | Administrative & support | 2023 |
| Liparis LLP | | 2013 |
| Liquid Light Group Investments Ltd | Real estate | 2022 |
| Liquid Light Group Limited | Information & communication | 2016 |
| Liquid Light Ltd | Information & communication | 2018 |
| Liquorice Dragon Ltd | Administrative & support | 2013 |
| Liquorice Dragon Media Ltd | Arts & recreation | 2018 |
| LIS Fabulous Homes Ltd | Administrative & support | 2021 |
| Lisa LI Consulting Limited | Professional & scientific | 2022 |
| Lisgar Holdings Limited | Financial services | 2025 |
| Lisminton Ltd | Professional & scientific | 2022 |
| Lister Francis Limited | Professional & scientific | 2022 |
| Little Angels (Sussex) Limited | Education | 2006 |
| Little Bears Day Nursery (Hove Actually) Ltd | Education | 2019 |
| Little Blooms Ltd | Arts & recreation | 2026 |
| Little Brook House Ltd | Health & social care | 2003 |
| Little Bruce Coffee Ltd | Manufacturing | 2024 |
| Little Courtenay Limited | Real estate | 2010 |
| Little Lambs Kindergarten Ltd | Education | 2010 |
| Little Minds Big Imaginations Ltd | Health & social care | 2024 |
| Little Pook Hill Limited | Real estate | 2021 |
| Little Steps With Laurann Ltd | Education | 2025 |
| Little Tree Woodcraft Ltd | Administrative & support | 2015 |
| Littlehampton Hotels Co. (1966) Limited | Hospitality | 1966 |
| Littlewood Farm Solar Limited | Energy | 2013 |
| LIV Organic Company Limited | Wholesale & retail | 2013 |
| Live Web Chat Limited | Information & communication | 2018 |
| LIVE4LIFE Properties Ltd | Real estate | 2024 |
| Living Colour Landscapes Limited | Administrative & support | 2010 |
| Living Shapes Ltd | Real estate | 2023 |
| Livingstone Homes Ltd | Real estate | 2025 |
| Livingstone Road Management Company Limited | Households | 2024 |
| Livvy's Consultants Ltd | Professional & scientific | 2006 |
| Livvys Mobile Ltd | Information & communication | 2010 |
| LIZ Forte Marketing Limited | Professional & scientific | 2011 |
| Lizard Heat Limited | Professional & scientific | 2016 |
| Lizzie Chambers Ltd | Arts & recreation | 2007 |
| LJ Keehan Property Limited | Real estate | 2025 |
| LJ Wellness Ltd | Hospitality | 2025 |
| Ljmn Ltd | Health & social care | 2023 |
| LK Builder Services Ltd | Construction | 2015 |
| LK Trichology Limited | Professional & scientific | 2017 |
| LL Asset Holdings Ltd | Real estate | 2026 |
| Lljf Ltd | Public administration | 2022 |
| LLM Brthers Limited | Hospitality | 2025 |
| Lloyd Sharman Engineering Ltd | Professional & scientific | 2014 |
| Lloyds Lettings Brighton and Hove Ltd | Real estate | 2018 |
| LM Logistics Group Ltd | | 2009 |
| Lmac Ltd | Professional & scientific | 2009 |
| LMC Security Limited | Administrative & support | 2017 |
| Lmfn Ltd | Health & social care | 2026 |
| LMG Property Limited | Real estate | 2018 |
| LMJ Church Road Ltd | Hospitality | 2021 |
| LMJ Lets Limited | Real estate | 2022 |
| Lndb Limited | Construction | 2023 |
| LNJ Properties Ltd | Real estate | 2024 |
| Lnorrie Limited | Health & social care | 2016 |
| Lobster and Pickle Ltd | Financial services | 2018 |
| Lobster POT Properties Ltd | Construction | 2021 |
| Local Celebrity Limited | Information & communication | 2006 |
| Locate Global Ltd | Administrative & support | 2020 |
| Lockstar Consulting Limited | Information & communication | 2018 |
| Loco Promotions Ltd | Arts & recreation | 2012 |
| Logiealmond Construction Ltd | Construction | 2024 |
| Logistics & Security Consultancy Limited | Administrative & support | 2011 |
| LOGO-2-GO Ltd | Manufacturing | 2024 |
| Logos Publisher Ltd | Information & communication | 2023 |
| Lollyuk Ltd | Administrative & support | 2016 |
| Lombok Land Limited | Real estate | 2023 |
| Lomi Lomi Design Limited | Information & communication | 2019 |
| Lomondsec Limited | Information & communication | 2024 |
| London and Hove Investments Ltd. | Real estate | 2016 |
| London by Sea Ltd | Arts & recreation | 2014 |
| London Geometry Ltd | Administrative & support | 2011 |
| London Media Hub Limited | Information & communication | 2021 |
| London Motor Market Ltd | Wholesale & retail | 2026 |
| London Picture Restoration Limited | Arts & recreation | 2019 |
| London Pipeservices Ltd | Construction | 2019 |
| London Square (Hayes BR2) Management Company Limited | Households | 2015 |
| Long Newnton Solar Farm Limited | Energy | 2013 |
| Long PIG Games Ltd | Information & communication | 2022 |
| Longanimals Ltd | Information & communication | 2010 |
| Longstride Capital Ltd | Financial services | 2024 |
| Look Studios LLC Ltd | Other services | 2020 |
| Loop Loop Ltd | Manufacturing | 2020 |
| Lordans Leadwork Ltd | Construction | 2024 |
| Lords INK Tattoo Studio Limited | Arts & recreation | 2012 |
| Loredana Limited | Administrative & support | 2013 |
| Loremin Estates Ltd | Real estate | 2025 |
| Lorna Belle Limited | Households | 1997 |
| Lorna Road Owners RTM Company Limited | Households | 2022 |
| Lorne Residential Ltd | Real estate | 2023 |
| Lorraine Court (Hove) Limited | Households | 1957 |
| Lorraine Court Hove RTM Company Limited | Hospitality | 2006 |
| Loser Trading Company Limited | Wholesale & retail | 2026 |
| Lost Games Ltd | Information & communication | 2026 |
| Lotb Ltd | Water & waste | 2021 |