| Lakeside Construction Ltd | Construction | 2026 |
| Languard House Association Limited | Households | 2004 |
| Lantara Property and Maintenance Limited | Real estate | 2021 |
| Lanthwaite Consulting Ltd | Information & communication | 2017 |
| Lapwing International Limited | Administrative & support | 2016 |
| Large & Gibson LLP | | 2024 |
| Laundrycare Limited | Other services | 2015 |
| Laurence Groves Consultancy Services Ltd | Extraterritorial | 2014 |
| Law Telecoms Ltd | Information & communication | 2020 |
| Lawless Apparel Limited | Wholesale & retail | 2016 |
| Lawson Rowe Limited | Administrative & support | 2023 |
| Lazy Susan Limited | Wholesale & retail | 2007 |
| LDC D&B Ltd | Construction | 2026 |
| LDN Equestrian Sport Ltd | Agriculture & fishing | 2022 |
| LE Beaux Ltd | Other services | 2024 |
| LE Priole Ltd | Health & social care | 2014 |
| Leak Detection Company South Limited | Other services | 2021 |
| Leapfrog Nursery School Limited | Education | 1999 |
| Ledgerfield Limited | Information & communication | 2025 |
| Ledgeway Construction Ltd | Construction | 2019 |
| LEE Johnson Joinery Ltd | Construction | 2019 |
| Legal and Support Services Limited | Professional & scientific | 2010 |
| Leightech Limited | Wholesale & retail | 2016 |
| Leilamezze Limited | Hospitality | 2016 |
| Lennox Mansions Management Company Limited | Households | 2004 |
| Lennox Mansions Residents Limited | Households | 2005 |
| Lennox Views RTM Company Limited | Hospitality | 2007 |
| LG Dodkins Limited | Information & communication | 2021 |
| Liangyou Sushi-Ya Ltd | Hospitality | 2025 |
| Liberty Lady JEN Ltd | Professional & scientific | 2022 |
| Liberty Photography Ltd | Professional & scientific | 2017 |
| Libra Bidco Limited | Financial services | 2022 |
| Libra Holdco Limited | Financial services | 2022 |
| Libra Midco Limited | Financial services | 2022 |
| Libra Topco Limited | Professional & scientific | 2025 |
| Librito Ltd | Information & communication | 2026 |
| Lidbury Limited | Hospitality | 2011 |
| Liesel Limited | Wholesale & retail | 2023 |
| Life Wont Wait Tattoos Limited | Arts & recreation | 2015 |
| Lifecare Wellness Recruitment Ltd | Health & social care | 2017 |
| Liftingz Ltd | Information & communication | 2025 |
| Light Works Solutions Limited | Construction | 2011 |
| Lighthouse Professionals Limited | Health & social care | 2022 |
| Lihou Walker Property Ltd | Households | 2019 |
| Limitless Engineering Limited | Professional & scientific | 2024 |
| Lin's Thai Café Ltd | Hospitality | 2019 |
| Lincoln South Limited | Professional & scientific | 2020 |
| Linda Jane Limited | Health & social care | 2016 |
| Lindon Court Management Company Limited | Households | 2005 |
| Line Crew Construction Ltd | Construction | 2015 |
| Lions Food UK Ltd | Hospitality | 2023 |
| Lisa Dawson Ltd | Wholesale & retail | 2020 |
| Litte BEE Soap Co. Ltd | Wholesale & retail | 2022 |
| Litten Properties Limited | Real estate | 2003 |
| Little Coffee Southsea Limited | Hospitality | 2021 |
| Little Lobster Co Ltd | Hospitality | 2025 |
| Little Minds Big Dreams Limited | Education | 2014 |
| Little Purl Co Ltd | Manufacturing | 2025 |
| Liwa Import Ltd | Wholesale & retail | 2025 |
| LJ Waste & Maintenance Ltd | Water & waste | 2019 |
| LL Data Point Limited | Information & communication | 2013 |
| LMN Ltd | Administrative & support | 2016 |
| Loammy Soft Ltd | Professional & scientific | 2022 |
| Local Coffee Limited | Hospitality | 2023 |
| Lock Stock and Tackle Limited | Wholesale & retail | 2024 |
| Locksway Food Ltd | Hospitality | 2026 |
| Logesh Ltd | Wholesale & retail | 2026 |
| London Garments Ltd | Wholesale & retail | 2025 |
| Longman Court Residents Limited | Households | 2007 |
| Loreign Ltd | Health & social care | 2018 |
| Louno Space Education CIC | Education | 2026 |
| Louno Space Limited | Education | 2022 |
| Love-Afrohub Ltd | Wholesale & retail | 2025 |
| Lovehrsolutions Limited | Administrative & support | 2011 |
| LOW Carbon Construction Developments Limited | Construction | 2014 |
| LSA Comms Ltd | Professional & scientific | 2013 |
| Luli Investments Ltd | Real estate | 2026 |
| Lunade Group Limited | Financial services | 2021 |
| Lupa Films Ltd | Information & communication | 2025 |
| Lupin Kitchens Ltd | Manufacturing | 2012 |
| Lupulus Limited | Information & communication | 2014 |
| Lustox Global Ltd | Information & communication | 2025 |
| Lutchmy Care Services Limited | Health & social care | 2004 |
| LUX Almeida Limited | Professional & scientific | 2025 |
| Luxe Beauty Salon Ltd | Other services | 2025 |
| Luxe Facial Ltd | Other services | 2025 |
| Luxe Professional Cleaning Limited | Administrative & support | 2018 |
| Luxmedics Limited | Professional & scientific | 2021 |
| Lwazi Data Solutions Limited | Information & communication | 2016 |
| LWK Developments Limited | Construction | 2017 |
| Lyndhurst Spice Limited | Hospitality | 2010 |
| Lzenithaxis Ltd | Wholesale & retail | 2026 |
| M and C Plastering Ltd | Construction | 2014 |
| M and G Portsmouth Property Limited | Real estate | 2026 |
| M and H MOT Station Ltd | Wholesale & retail | 2023 |
| M Developments 88 Ltd | Construction | 2025 |
| M Electrical Services Ltd | Construction | 2021 |
| M Floyd Electrical Ltd | Construction | 2024 |
| M Jones Decorating Services Ltd | Construction | 2014 |
| M S Ahmed Investments Ltd | Real estate | 2019 |