| Lloyd Builders & Carpenters Limited | Construction | 2004 |
| Lloyd PR Ltd | Professional & scientific | 2020 |
| Llwyndyrys Care Limited | Professional & scientific | 2004 |
| Llwyndyrys Residential Home Limited | Health & social care | 1999 |
| Llys Felin Newydd Management Company Limited | Real estate | 1989 |
| Llys Glasfryn Phase 2 Management Company Limited | Real estate | 2021 |
| Llysgwyn House Limited | Health & social care | 2013 |
| LM Cottages Ltd | Real estate | 2025 |
| LMD Property Developments Limited | Households | 2020 |
| LME Housing Limited | Real estate | 2026 |
| LMJ Business Solutions Ltd | Professional & scientific | 2016 |
| LMR Homes Ltd | Real estate | 2024 |
| LMS (Wales) Limited | Construction | 2014 |
| LMT Automotive Ltd | Wholesale & retail | 2024 |
| LN Estate Holdings Ltd | Real estate | 2022 |
| Lnas Services Ltd | Construction | 2021 |
| Lnbits, Inc Limited | Information & communication | 2022 |
| LO Oasis Limited | Real estate | 2017 |
| Loans UN Limited | Extraterritorial | 2013 |
| Lobo Capital LLP | | 2019 |
| LOC IT and Leave IT Limited | Manufacturing | 2022 |
| Local AID for Children and Community Special Needs | Education | 2003 |
| Local Kooks Ltd | Wholesale & retail | 2025 |
| Local Pharmacy Group Limited | Wholesale & retail | 2023 |
| Local Property (South West) Ltd | Administrative & support | 2007 |
| Local Shop Ltd | Wholesale & retail | 2012 |
| Locally Baked Limited | Wholesale & retail | 2023 |
| Localtradesswansea Ltd | Information & communication | 2026 |
| Locarno Ground Rents Limited | Real estate | 2025 |
| Locate HMO Ltd | Real estate | 2018 |
| Lock Forward Training Ltd | Education | 2020 |
| Lock UP Hub Ltd | Real estate | 2018 |
| Locked Media Limited | Administrative & support | 2022 |
| Lockland Limited | Professional & scientific | 2010 |
| Lockout 24-7 Limited | Construction | 2021 |
| Locum Optics Limited | Wholesale & retail | 2025 |
| Lodge and Chapter Limited | Wholesale & retail | 2011 |
| Logan and Allan Limited | Wholesale & retail | 2001 |
| Logic Artist Management Ltd Limited | Information & communication | 2022 |
| Logic Fast Snax Limited | Hospitality | 2021 |
| Logic Festival UK Ltd | Hospitality | 2022 |
| Logic Systems Limited | Information & communication | 1986 |
| Logiclay Limited | Professional & scientific | 2019 |
| Logistic Support Division Ltd | Transport & logistics | 2023 |
| Loil Ltd | Wholesale & retail | 2022 |
| LOK Box Limited | Manufacturing | 2023 |
| Lokkey Ltd | Hospitality | 2017 |
| LON Arian Technical Services Limited | Manufacturing | 2017 |
| Londis Ystrad Ltd | Wholesale & retail | 2022 |
| London and Oriental Holdings Limited | Professional & scientific | 2002 |
| London Boutiques Ltd | Wholesale & retail | 2020 |
| London Center for Analytics Ltd | Information & communication | 2025 |
| London Engineering Limited | Manufacturing | 2019 |
| Londonrewires Ltd | Construction | 2017 |
| Londons Brick Cleaning Company Ltd | Administrative & support | 2019 |
| Long Oaks Investments Limited | Real estate | 2020 |
| Long Trails & Sleepy Tails Ltd | Other services | 2024 |
| Long's Tech Ltd | Other services | 2021 |
| Longford Investment (NO 1) Limited | Real estate | 2006 |
| Longford Investment (NO 2) Limited | Real estate | 2009 |
| Longford Investment Limited | Agriculture & fishing | 2006 |
| Longpark Limited | Real estate | 1996 |
| Longs Landscaping Ltd | Administrative & support | 2024 |
| Lonlas Developments Limited | Real estate | 2022 |
| Lookdeeper Limited | Information & communication | 2021 |
| Loopeto Limited | Administrative & support | 2021 |
| Loosemore Delivery Services Ltd | Transport & logistics | 2023 |
| Lorax Construction Ltd | Administrative & support | 2015 |
| Lorax Homes Limited | Construction | 2018 |
| Lord Land Lettings Limited | Real estate | 2022 |
| Loren Holdings Limited | Financial services | 2026 |
| Lorries UN Limited | Extraterritorial | 2013 |
| Los-Launderama Ltd | Other services | 2010 |
| Lost Boys Ltd | Hospitality | 2023 |
| Lotola Property Group Limited | Real estate | 2024 |
| Lottiedots Enterprises Limited | Real estate | 2025 |
| Lotus Hospitality Limited | Hospitality | 2018 |
| Lotus House (Wales) Limited | Hospitality | 2005 |
| Lotus House Properties Limited | Real estate | 2020 |
| Lotus Life Holdings Ltd | Financial services | 2026 |
| Lotus Life Review Ltd | Financial services | 2022 |
| Lotus Nails and Beauty 91 Ltd | Other services | 2025 |
| Lotus Thai on Sea Limited | Hospitality | 2025 |
| Louisa Grace Interiors Limited | Manufacturing | 2014 |
| Louisa Johnson Ltd | Extraterritorial | 2024 |
| Louisa Pankhurst Johnson Ltd | Extraterritorial | 2024 |
| Louise Burgess Events Ltd | Administrative & support | 2014 |
| Loumor Gowns Ltd | Wholesale & retail | 2018 |
| Love 2 Recycle Ltd | Water & waste | 2010 |
| Love YOU a Latte Ltd | Hospitality | 2021 |
| Lovell Roofing Ltd | Construction | 2025 |
| Lovely Stuff Studio Limited | Information & communication | 2015 |
| Lovely Town CIC | Arts & recreation | 2025 |
| Lovii Ltd | Wholesale & retail | 2013 |
| Lowe Legal Services Limited | Professional & scientific | 2009 |
| LP Property Lettings Limited | Real estate | 2024 |
| LP019599 LP | | 2018 |
| LP019600 LP | | 2018 |
| LP020987 LP | | 2020 |
| LP3 Ltd | Real estate | 2022 |