| Lotus Financial Management Limited | Professional & scientific | 2023 |
| Louisa Smurthwaite Ltd | Arts & recreation | 2016 |
| Louise Richardson Studio Ltd | Professional & scientific | 2024 |
| Lout Events Limited | Arts & recreation | 2006 |
| Love Gardens Community CIC | Administrative & support | 2026 |
| Love Hospitality Limited | Administrative & support | 2015 |
| Love Matters Limited | Information & communication | 2015 |
| Lovelocaljobs Foundation C.I.C. | Other services | 2014 |
| Lovelocaljobs.Com Limited | Administrative & support | 2013 |
| Lovelylook Ltd | Other services | 2013 |
| Lowen Scot Limited | Real estate | 2024 |
| Lowther Road 1970 Limited | Extraterritorial | 2015 |
| Loxwood Constructions Ltd | Construction | 2021 |
| LPD Scaffolding Ltd | Construction | 2020 |
| LQ Nova Ltd | Wholesale & retail | 2026 |
| LQG Consulting Ltd | Construction | 2024 |
| Lrdp Property Limited | Real estate | 2023 |
| LRM Consulting Ltd | Information & communication | 2018 |
| LRW Mobile Bodywork Ltd | Wholesale & retail | 2023 |
| LS Healthcare Solutions Ltd | Health & social care | 2024 |
| Lspi Ltd | Real estate | 2024 |
| Lstc Limited | Information & communication | 2011 |
| LTL Consultants Ltd | Financial services | 2014 |
| Ltro Perrymount Ltd | Real estate | 2023 |
| Luansiga Ltd | Other services | 2016 |
| Lubia Limited | Professional & scientific | 2023 |
| Lucas Tech Ltd | Wholesale & retail | 2025 |
| Lucia Lenartova Limited | Health & social care | 2015 |
| Lucid Ltd | Professional & scientific | 2009 |
| Lucie MAY Limited | Health & social care | 2023 |
| Lucky Dog Design Limited | Arts & recreation | 2007 |
| Lucky Fortune Brighton Ltd | Hospitality | 2025 |
| Lucky Star 180 Ltd | Hospitality | 2026 |
| Lucky Star Takeaway Limited | Hospitality | 2015 |
| Lucky Technology Limited | Wholesale & retail | 2002 |
| LUCKY13 Properties Limited | Real estate | 2019 |
| Luctons Group Limited | Real estate | 2017 |
| Lucy Dracott Photography Ltd | Professional & scientific | 2024 |
| Lucy M Smith Ltd | Professional & scientific | 2020 |
| Ludlow Limited | Wholesale & retail | 2024 |
| Luisa Kelsey Ltd | Wholesale & retail | 2018 |
| Luke & Luke Limited | Construction | 2002 |
| Luke Whiting Productions Limited | Information & communication | 2011 |
| Lukka Ltd | Professional & scientific | 2026 |
| Lumii Design Company Ltd | Manufacturing | 2022 |
| Lumimix Ltd | Other services | 2024 |
| Luminesco Ltd | Manufacturing | 2022 |
| Luna Maya Limited | Other services | 2024 |
| Lunabet Limited | Financial services | 2025 |
| Lunar Renovations Limited | Construction | 2012 |
| Lusacuro Limited | Administrative & support | 2013 |
| Lusent Limited | Arts & recreation | 2023 |
| Lustry Nails Ltd | Other services | 2025 |
| Luxe Key Rentals Ltd | Real estate | 2026 |
| Luxe Touch Studio Ltd | Other services | 2023 |
| Luxor Properties (Sussex) Ltd | Real estate | 2016 |
| Luxwho Ltd | Professional & scientific | 2015 |
| Lvjpharma Ltd | Professional & scientific | 2020 |
| LW Medical Limited | Health & social care | 2020 |
| LWD Consultancy Ltd | Professional & scientific | 2019 |
| LX Properties (Norman Road) Ltd | Construction | 2019 |
| LX Properties Holdings Ltd | Real estate | 2019 |
| LX Properties Hughenden Ltd | Construction | 2018 |
| LX Properties Limited | Construction | 2016 |
| Lyfe Flow Limited | Information & communication | 2024 |
| Lyfe Group Limited | Information & communication | 2024 |
| Lyfe Health Limited | Information & communication | 2024 |
| Lyfe Health Technologies Limited | Information & communication | 2024 |
| Lynden House Properties Ltd | Real estate | 2018 |
| Lynn West Ltd | Professional & scientific | 2003 |
| Lyons Ecological Interpretation Ltd | Professional & scientific | 2024 |
| Lyrd Ltd | Hospitality | 2025 |
| Lyric Hammersmith Ltd | Real estate | 2024 |
| Lyst Consulting Group Ltd | Information & communication | 2019 |
| Lytle Financial Services Limited | Financial services | 1998 |
| M & B News Ltd | Wholesale & retail | 2019 |
| M & F Freight Forwarder Ltd | Wholesale & retail | 2022 |
| M & G Properties (Sussex) Limited | Real estate | 1999 |
| M & N Carwash Limited | Wholesale & retail | 2026 |
| M & T Property Investment Limited | Real estate | 2016 |
| M & W Leathers Limited | Wholesale & retail | 2002 |
| M B Brighton Ltd | Construction | 2011 |
| M B Roofing Holdings Ltd | Financial services | 2024 |
| M B Roofing Limited | Construction | 2003 |
| M Dynasty Records Ltd. | Information & communication | 2017 |
| M G Mitchell Limited | Construction | 2002 |
| M Goacher Heating Ltd | Construction | 2021 |
| M J Staples Property Management (Brighton) Limited | Real estate | 1988 |
| M M a Real Estate Ltd | Real estate | 2020 |
| M Mensah (Locum) Ltd | Health & social care | 1998 |
| M P Property (Sussex) Ltd | Construction | 2025 |
| M R Communications Ltd | Professional & scientific | 2019 |
| M&B Decorating Services Ltd | Construction | 2025 |
| M&G Holdings (Sussex) Ltd | Financial services | 2017 |
| M&H Properties Brighton Limited | Real estate | 2016 |
| M&M Distribution (Sussex) Limited | Wholesale & retail | 2009 |
| M&R Hove Limited | Wholesale & retail | 2025 |
| M&S Restorations Limited | Administrative & support | 2005 |
| M&V Auto Care Limited | Wholesale & retail | 2026 |
| M. Pettitt Limited | Construction | 2004 |