| Link Fibre Ltd | Construction | 2024 |
| Linkhaven Estates Ltd | Real estate | 2004 |
| Linkrank Solutions Ltd | Information & communication | 2026 |
| Lionhub Ltd | Wholesale & retail | 2026 |
| Lippco Limited | Real estate | 2018 |
| Lips Inc Academy Limited | Other services | 2021 |
| Lirat PAY Ltd | Information & communication | 2026 |
| Liston Investments Limited | Real estate | 2003 |
| Liteblue Ltd | Professional & scientific | 1998 |
| Little Cherubs Kindergarten Limited | Administrative & support | 2003 |
| Little Eskimo Limited | Wholesale & retail | 2005 |
| Little Hall Farms Limited | Agriculture & fishing | 1972 |
| Little Jimmys Preschool Group Ltd | Education | 2025 |
| Little Pumpkins | | 2007 |
| Little Puppy Limited | Wholesale & retail | 2024 |
| Little Rock Electronics Limited | Information & communication | 1998 |
| Live the Dream Property Limited | Real estate | 2004 |
| Live With Intent Ltd | Arts & recreation | 2019 |
| Living Life My Style Ltd | Professional & scientific | 2022 |
| Livingspring Group Limited | Manufacturing | 2005 |
| Liza Limited | Professional & scientific | 2003 |
| LK Associates Limited | Hospitality | 2020 |
| Lloyds of Leyton Limited | Administrative & support | 1962 |
| LLS 34 Ltd | Wholesale & retail | 2025 |
| Llysyn Medical Ltd | Health & social care | 2025 |
| LMD Services and Consulting Ltd | Manufacturing | 2026 |
| LMG Ltd | Wholesale & retail | 2025 |
| Loaj Services Ltd | Information & communication | 2020 |
| Localtrend Ltd | Wholesale & retail | 2026 |
| Lochaber Energy Centre Limited | Energy | 2022 |
| Lock Inn Ltd | Hospitality | 2005 |
| Lockflame Fire Solutions Ltd | Professional & scientific | 2024 |
| Locksons Consultancy Limited | Real estate | 2024 |
| Locums Solution Ltd | Health & social care | 2022 |
| Lodestar Care Ltd | Health & social care | 2026 |
| Loftme Ltd | Wholesale & retail | 2009 |
| LOG Management Limited | Administrative & support | 2024 |
| Logical Business Analysis Limited | Information & communication | 2006 |
| Logical Marketing Ltd | Information & communication | 2022 |
| Logion Limited | Wholesale & retail | 2000 |
| Logitech Solution Services Ltd | Information & communication | 2025 |
| Logos Theatre Company Ltd | Arts & recreation | 2005 |
| Logun Healthcare Services Limited | Health & social care | 2026 |
| Lohsam Limited | Information & communication | 2017 |
| Lokatech IT Limited | Information & communication | 2007 |
| London Accountancy Limited | Professional & scientific | 2002 |
| London Chimney Lining Limited | Administrative & support | 2024 |
| London Construction (UK) Limited | Construction | 2007 |
| London Ground Force DPN Ltd | Construction | 2019 |
| London Lush Support Services Ltd | Administrative & support | 2023 |
| London Medical Courses Ltd | Health & social care | 2025 |
| London Modular Systems Ltd | Construction | 2019 |
| London One Stop Solution Ltd | Other services | 2014 |
| London SIA Training Ltd | Education | 2025 |
| London Sportswise Ltd | Health & social care | 2007 |
| London Structural Consultants Ltd | Professional & scientific | 2021 |
| London Tyers Ltd | Other services | 2018 |
| London Wheels Ltd | Wholesale & retail | 2023 |
| Longreach Estates Ltd | Real estate | 2006 |
| Longs Packaging Limited | Wholesale & retail | 1976 |
| Lonore UK Ltd | Information & communication | 2022 |
| Look Left Ltd | Administrative & support | 2017 |
| Lord of Mussels London Ltd | Hospitality | 2025 |
| Lord Petre's Farms Limited | Agriculture & fishing | 1954 |
| Lordsfield Limited | Wholesale & retail | 1992 |
| Lornik Property Services Ltd | Real estate | 2005 |
| Lorven Holdings Ltd | Real estate | 2025 |
| Lost Cousins Limited | Information & communication | 2004 |
| Loughton Grand Marquee Venue Ltd | Other services | 2026 |
| Loughtonsphere Ltd | Wholesale & retail | 2020 |
| Loui Hair Studio Limited | Other services | 2002 |
| Lounge India International Ltd | Hospitality | 2025 |
| Lovechild Trust | Professional & scientific | 2012 |
| Lovegrace Ltd | Health & social care | 2025 |
| Lovehealself Ltd | Manufacturing | 2023 |
| Lovekaizen Ltd | Information & communication | 2016 |
| Loves Farm Contracts Limited | Construction | 2002 |
| Lowe Brothers Contract Management Limited | Water & waste | 2004 |
| Lowestoft Ltd | Hospitality | 2013 |
| Lowfield Energy Centre Limited | Energy | 2021 |
| Loza Tech Services Ltd | Information & communication | 2024 |
| LP Thermal Insulations Ltd | Construction | 2019 |
| LPC Enterprises Ltd | Information & communication | 1995 |
| LPM Properties Limited | Construction | 1997 |
| LPR Consulting LLP | | 2007 |
| LR Gyms Ltd | Arts & recreation | 2025 |
| LSM B&M Ltd | Real estate | 2025 |
| LSM Partnership Ltd | Hospitality | 2025 |
| LSV Family Partners Ltd | Construction | 2025 |
| Ltaviner Limited | Extraterritorial | 2021 |
| Lubart Limited | Professional & scientific | 2001 |
| Lubima 2006 Limited | Construction | 2007 |
| Lubimka Limited | Administrative & support | 2026 |
| Lucie Attwell Limited | Arts & recreation | 1959 |
| Lucky Four Leaf Limited | Hospitality | 2022 |
| Lullaby Day Nurseries Ltd | Health & social care | 2026 |
| Lullaby Day Nursery Group Ltd | Financial services | 2026 |
| Lullaby Day Nursery Limited | Real estate | 2026 |
| Lulu's Foods Ltd | Hospitality | 2024 |
| Lumeau Ltd | Wholesale & retail | 2025 |