| LM28 Properties Limited | Real estate | 2025 |
| LMB Equine Ltd | Agriculture & fishing | 2021 |
| LMG Legal Ltd | Professional & scientific | 2026 |
| LMH Property Services Yorkshire Limited | Construction | 2016 |
| Lmmj Limited | Arts & recreation | 2026 |
| LNR 247 Locksmiths & Training Academy Ltd | Other services | 2017 |
| LNR 247 Training Academy Limited | Construction | 2018 |
| Loadstar Consultancy Limited | Professional & scientific | 2025 |
| Loafers Vinyl and Coffee Limited | Wholesale & retail | 2017 |
| LOC Consultancy Ltd | Professional & scientific | 2025 |
| Local Grocery Ltd | Wholesale & retail | 2024 |
| Local Mags Ltd | Other services | 2011 |
| Locality Support Services Limited | Health & social care | 2008 |
| Locally Uncovered Ltd | Wholesale & retail | 2023 |
| Lockfit ( Leeds) Ltd | Construction | 2025 |
| Lockstitch Engineering Limited | Professional & scientific | 2022 |
| Lockwood Precision Engineering Limited | Professional & scientific | 2019 |
| Locrx Ltd | Health & social care | 2025 |
| Lodge Joinery Manufacturing Limited | Manufacturing | 1977 |
| Lofthome Limited | Construction | 1990 |
| Logicon Services Limited | Construction | 2017 |
| Lombray Poplar Ltd | Wholesale & retail | 2025 |
| Long Lover Livery Limited | Arts & recreation | 2004 |
| Long Mill Carpets Limited | Wholesale & retail | 2014 |
| Long Mill Edging Limited | Wholesale & retail | 2018 |
| Long Tide Ltd | Manufacturing | 2025 |
| Longdog Audio Limited | Manufacturing | 2011 |
| Longley Construction Ltd | Construction | 2015 |
| Longthorpe Timepieces Limited | Wholesale & retail | 2022 |
| Look 4 Mortgages Ltd | Professional & scientific | 2023 |
| Look Glass Ltd | Wholesale & retail | 2025 |
| Loop Portal UK Limited | Extraterritorial | 2020 |
| Lord Capital Holdings Ltd | Financial services | 2024 |
| Lord’S Venetian Plastering Ltd | Construction | 2024 |
| LOS Pampas Group Limited | Hospitality | 2018 |
| Lost and Found Wellbeing CIC | Education | 2026 |
| Love 2 BE (Halifax) Limited | Construction | 2017 |
| Love and Pamper Limited | Wholesale & retail | 2018 |
| Love Furniture Bradford Ltd | Manufacturing | 2016 |
| Love Luxury Lettings Limited | Hospitality | 2025 |
| Loveholiday Flights Ltd | Other services | 2025 |
| Lower Brockholes Farm Ltd | Other services | 2024 |
| Lower Giles Hill Farm Limited | Agriculture & fishing | 2005 |
| Lower Wynteredge Farm Ltd | Agriculture & fishing | 2003 |
| Lowerfield Plumbing & Heating Ltd | Construction | 2012 |
| Lowfields Caravan Sales Ltd | Wholesale & retail | 2018 |
| Loxley Benedict Holdings Ltd | Real estate | 2019 |
| Loxley Benedict Limited | Wholesale & retail | 2019 |
| Loxley Benedict Surplus Ltd | Wholesale & retail | 2025 |
| Loza Limited | Construction | 2018 |
| LP Sitesearch Ltd | Real estate | 2025 |
| LPH Racing Ltd | Arts & recreation | 2019 |
| LR2J Property Limited | Construction | 2025 |
| LRB Developments Limited | Construction | 2017 |
| LS Bookkeeping Services Limited | Professional & scientific | 2023 |
| LS Private Caravans Ltd | Real estate | 2023 |
| LSB Learning Ltd | Education | 2020 |
| Lsco Investments Limited | Financial services | 2025 |
| LSW Projects Limited | Construction | 2016 |
| LT Installations Ltd | Construction | 2017 |
| LT Ventures Limited | Hospitality | 2020 |
| LTC Leisure Services Ltd | Hospitality | 2023 |
| Lucas Payton Hearingcare Limited | Wholesale & retail | 2021 |
| Luck Contractors Ltd | Construction | 2025 |
| Lucky 13 Racing Limited | Wholesale & retail | 2014 |
| Lucky Buddha Group Ltd | Hospitality | 2026 |
| Luddendenfoot Community Association | Other services | 2009 |
| Ludlow Neston Ltd | Wholesale & retail | 2025 |
| Luigi's Pizza Limited | Hospitality | 2024 |
| Lukas Mediterranean Foods Ltd | Hospitality | 2023 |
| Lukasz Kuziak Transport Ltd | Transport & logistics | 2015 |
| Luke Finch Ltd | Professional & scientific | 2023 |
| Luke Greenwood Construction Management Limited | Construction | 2021 |
| Luke Hirst Business Consultants Ltd | Professional & scientific | 2026 |
| Lumaa Services Ltd | Professional & scientific | 2025 |
| Lumenstore Ltd | Wholesale & retail | 2026 |
| Lumina Innovations (Holdings) Limited | Information & communication | 2024 |
| Lumina Intelligence Ltd | Information & communication | 2024 |
| Luminaration Partners Ltd | Wholesale & retail | 2025 |
| Luminery Care Limited | Health & social care | 2021 |
| Luminous Square Clothing Limited | Wholesale & retail | 2025 |
| Lumora Digital Limited | Information & communication | 2025 |
| Lumos Innovations Ltd | Wholesale & retail | 2025 |
| Lumsden T Limited | Wholesale & retail | 2014 |
| Luna Nest Ltd | Wholesale & retail | 2025 |
| Lune Valley Court Management Co Ltd | Households | 1998 |
| Lunn Consulting Limited | Professional & scientific | 2023 |
| Lurcher Link Trust | Administrative & support | 2018 |
| Lushi Style Building Services Ltd | Construction | 2020 |
| Luton Operating Company Limited | Hospitality | 2016 |
| Luwik Limited | Transport & logistics | 2026 |
| LUX Addition Properties Ltd | Real estate | 2025 |
| LUX Scouting Ltd | Arts & recreation | 2023 |
| LUX Tyres Ltd | Wholesale & retail | 2021 |
| LUX Tyres Mobile Tyre Fitting Ltd | Wholesale & retail | 2022 |
| LUX Valeting Ltd | Administrative & support | 2021 |
| Luxe Card Studio Ltd | Manufacturing | 2025 |
| Luxe Tanning Products Ltd | Wholesale & retail | 2026 |
| Luxeme Ltd | Other services | 2025 |
| Luxora Haus Ltd | Wholesale & retail | 2025 |