| London Waste Warriors Ltd | Water & waste | 2026 |
| Londonwide Driving School Ltd | Education | 2025 |
| Londwood Ltd | Construction | 2018 |
| Longman & George Limited | Wholesale & retail | 2011 |
| Longwood Construction Limited | Construction | 1971 |
| Lonis Assessment Ltd | Health & social care | 2022 |
| Lookersnew Re-Gen . Co . Ltd | Construction | 2021 |
| Lord Media Ltd | Professional & scientific | 2019 |
| Lords Club Group Limited | Other services | 2022 |
| Lords Footwear Limited | Wholesale & retail | 2018 |
| Lore & Raul Limited | Wholesale & retail | 2018 |
| Lost Cause Tattoo Ltd | Other services | 2020 |
| LOT Supplies Ltd | Information & communication | 2012 |
| Lotus Testing Ltd | Information & communication | 2019 |
| LOU LA Belles Beauty Ltd | Wholesale & retail | 2016 |
| Louis Power Maintenance Services Ltd | Energy | 2024 |
| LOV4 Logistics Limited | Transport & logistics | 2025 |
| Love Ball Ltd | Education | 2026 |
| Love to Sing (UK) Limited | Education | 2013 |
| Lovefreight Ltd | Transport & logistics | 2010 |
| Lovetraveltravel.Com Limited | Administrative & support | 2023 |
| Lovewarehousing Limited | Transport & logistics | 2013 |
| LOW Carbon Technology Limited | Administrative & support | 2009 |
| LOW Cost Home Improvements Limited | Construction | 2012 |
| Lowell Receivables Financing 1 Limited | Financial services | 2018 |
| Loxford Management Limited | Real estate | 2022 |
| LRC Electrical Limited | Construction | 2023 |
| LRM Interior Solutions Ltd | Construction | 2020 |
| LRP Homes Limited | Other services | 2019 |
| LS Automotive Essex Ltd | Manufacturing | 2021 |
| LS Smart Power Ltd | Construction | 2025 |
| LSB Building & Maintenance Ltd | Construction | 2020 |
| Lservices Ltd | Construction | 2023 |
| LSJ Engineering Holdings Limited | Financial services | 2024 |
| LSJ Engineering Ltd | Construction | 2006 |
| LSR Entertainment Ltd | Arts & recreation | 2022 |
| LT AC Ltd | Energy | 2023 |
| LT Plant Hire Limited | Construction | 2014 |
| LTC Electrical Limited | Construction | 2025 |
| Luamak Limited | Financial services | 2019 |
| Luan Motors Ltd | Wholesale & retail | 2021 |
| Luben Developments Ltd | Construction | 2023 |
| Lucas Agencies Limited | Wholesale & retail | 2013 |
| Lucas Valeting Ltd | Other services | 2024 |
| Lucian Haulage Limited | Transport & logistics | 2016 |
| Lucky Shark Limited | Manufacturing | 2010 |
| Lucky Star UK Basildon Limited | Hospitality | 2025 |
| Luckydog Consulting Limited | Information & communication | 2015 |
| Luggage Travel Bags Limited | Administrative & support | 2010 |
| Lukanov Transport Ltd | Transport & logistics | 2018 |
| Lukaro.Shop Ltd | Wholesale & retail | 2021 |
| Lukasz Markiewicz Drywall Ltd | Construction | 2021 |
| Lukin Family Ltd | Construction | 2025 |
| Lullaway Construction Ltd | Construction | 2019 |
| Lulu Glass GM Limited | Construction | 2023 |
| Lumine Estates Limited | Real estate | 2025 |
| Luminia Limited | Health & social care | 2025 |
| Luna Dynamics Limited | Professional & scientific | 2022 |
| Luna Property Developments Ltd | Construction | 2026 |
| LUX Medispa Ltd | Other services | 2019 |
| LUX Retail Ltd | Other services | 2026 |
| Luxe Green Limited | Information & communication | 2019 |
| Luxe Travel Essex Limited | Transport & logistics | 2025 |
| Luxem Services Ltd | Hospitality | 2023 |
| Luxol LLP | | 2019 |
| Luxurious Hair Ltd | Other services | 2019 |
| Luxury in the MED Limited | Administrative & support | 1960 |
| Luxus Lifestyle Management Limited | Other services | 2021 |
| Luxx Living Ltd | Wholesale & retail | 2019 |
| LV Business Corp Limited | Wholesale & retail | 2019 |
| LV Group MOT & Service Centre Ltd | Wholesale & retail | 2021 |
| Lvng Developments Limited | Real estate | 2026 |
| LW Pipe Fabrications Limited | Construction | 2018 |
| LW Pipe Services Limited | Construction | 2024 |
| Lwarne Ltd | Construction | 2018 |
| LWD Training Limited | Administrative & support | 2024 |
| Lxpc Ltd | Professional & scientific | 2013 |
| LXT Projects Limited | Construction | 2024 |
| Lygos Trading Limited | Wholesale & retail | 2015 |
| Lymphatic and Hydro Facial Limited | Other services | 2025 |
| Lyons Commissioning Services Limited | Administrative & support | 2026 |
| Lyron Construction Limited | Construction | 2018 |
| Lyron Group Limited | Financial services | 2025 |
| Lyron Property Limited | Real estate | 2021 |
| M & a Mechanical Services Ltd | Administrative & support | 2008 |
| M & C Property Maintenance Ltd | Real estate | 2025 |
| M & E (UK) Limited | Administrative & support | 2005 |
| M & H Smith Limited | Professional & scientific | 2021 |
| M & J Heating & Plumbing Limited | Construction | 2007 |
| M & J Services Group Limited | Professional & scientific | 2018 |
| M & J Services Ltd | Construction | 2002 |
| M & PEE Ltd | Health & social care | 2015 |
| M and N Property Renovation Ltd | Real estate | 2018 |
| M Ayres Property Ltd | Real estate | 2019 |
| M Brace Precious Jewellery Limited | Manufacturing | 2014 |
| M C Carpets Limited | Construction | 2013 |
| M Enslin UK Ltd | Professional & scientific | 2022 |
| M Fairman Piling Limited | Construction | 2018 |
| M G F Interiors Limited | Construction | 2015 |
| M J M Holdings & Estates Limited | Real estate | 2010 |