| Lighthouse Property Solutions Ltd | Administrative & support | 2014 |
| Lighthouse Systems Limited | Information & communication | 1990 |
| Lights 2 Go Limited | Extraterritorial | 2005 |
| Lightwood Commercial Services Limited | Professional & scientific | 2016 |
| Lihm Limited | Real estate | 2017 |
| Likeness Health Ltd | Health & social care | 2025 |
| Likewise Floors Limited | Wholesale & retail | 1996 |
| Likewise Group PLC | Wholesale & retail | 2012 |
| Likewise Holdings Limited | Real estate | 2009 |
| Likewise Limited | Extraterritorial | 2021 |
| Likewise Trading Limited | Extraterritorial | 2018 |
| LIL Holdco UK Limited | Financial services | 2021 |
| Lil-Lets UK Ltd | Wholesale & retail | 1955 |
| Lilac Holdings Ltd | Real estate | 2017 |
| Lily Gardens (Hilton) Residents Management Company Limited | Households | 2010 |
| Limber Fitness Ltd | Wholesale & retail | 2021 |
| Lime Key Investments Limited | Real estate | 2020 |
| Limepanda Limited | Administrative & support | 2015 |
| Limestone Way (Maresfield) Ltd | Construction | 2023 |
| Limitless by Patsys Ltd | Wholesale & retail | 2021 |
| Limitless Needs Ltd | Wholesale & retail | 2024 |
| Limitless Routes Ltd | Wholesale & retail | 2024 |
| Limner Street Freehold Limited | Households | 2023 |
| Limoja Ltd | Professional & scientific | 2026 |
| Lincs Investment Limited | Real estate | 2020 |
| Lindridge Chase Residents Management Company Limited | Households | 2023 |
| Linear Consultancy Limited | Professional & scientific | 2025 |
| Linens Online Ltd | Wholesale & retail | 2017 |
| Lines and Dots Ltd | Wholesale & retail | 2021 |
| Lingham Homes Ltd | Real estate | 2025 |
| Lingualink Company Ltd | Professional & scientific | 2025 |
| Linkit Communications Ltd | Information & communication | 2018 |
| Linksmart Limited | Professional & scientific | 2009 |
| Linman Di-Tech Ltd | Wholesale & retail | 2025 |
| Linnaeus Referrals Ltd | Professional & scientific | 2015 |
| Linnett Electrical Services Limited | Construction | 2016 |
| Lion Paradise Ltd | Real estate | 2019 |
| Lion Spedition Ltd | Transport & logistics | 2024 |
| Liongate Electric Vehicle Ltd | Wholesale & retail | 2021 |
| Lionweld Kennedy Flooring Limited | Manufacturing | 2004 |
| Lionweld Steel Limited | Manufacturing | 2011 |
| Liquid Management Holdings Limited | Financial services | 2024 |
| Liquid Software Solutions Ltd | Information & communication | 2003 |
| Lisa Marie Limited | Other services | 2003 |
| Lisle Agencies Limited | Real estate | 2014 |
| Listen Entertainment Limited | Information & communication | 2019 |
| Litespeed Property Investments Limited | Real estate | 2005 |
| Litewire Solutions Limited | Construction | 2005 |
| Lithium Property Investments Limited | Real estate | 2016 |
| Little Bundles Childminding Ltd | Health & social care | 2022 |
| Little Crags Properties Limited | Real estate | 2024 |
| Little MOO Limited | Professional & scientific | 2026 |
| Little Star Threads Ltd | Wholesale & retail | 2025 |
| Little View Limited | Hospitality | 2022 |
| Littledean Gardening and Maintenance Limited | Administrative & support | 2013 |
| Littlefield Lane Management Company Limited | Real estate | 2025 |
| LIV Storage Limited | Wholesale & retail | 2013 |
| Liverpool Bay Construction Limited | Other services | 2003 |
| Liveuptourname Ltd | Wholesale & retail | 2025 |
| Livin Cyclades Ltd | Wholesale & retail | 2021 |
| Living Overseas Properties Limited | Extraterritorial | 2009 |
| Living Space Housing Limited | Construction | 2018 |
| Living Worcester Ltd | Real estate | 2020 |
| Livingstone House Limited | Health & social care | 2022 |
| Livingstone Thompson Limited | Other services | 2006 |
| Livintel Ltd | Wholesale & retail | 2026 |
| LIZ Smith Interpreting Limited | Other services | 2011 |
| LJA Accounting Limited | Professional & scientific | 2015 |
| LJB Consulting Services Ltd | Information & communication | 2024 |
| LJC & JEC Ltd | Extraterritorial | 2020 |
| Ljempire Ltd | Hospitality | 2025 |
| LJR Commerce Limited | Professional & scientific | 2017 |
| LJR Holdings Ltd | Financial services | 2023 |
| LJR Property Development Ltd | Construction | 2024 |
| LJS Building Contractors Ltd | Construction | 2026 |
| LJW Electrical Contractors Ltd | Construction | 2025 |
| LKB Scaffolding Limited | Construction | 2025 |
| LKC Electrical Contracting Ltd | Construction | 2017 |
| Lkjn Limited | Professional & scientific | 2021 |
| LKR Marketing Limited | Professional & scientific | 2024 |
| LLJ Communications Ltd | Professional & scientific | 2022 |
| Lloyds Engineering Services (UK) Ltd | Construction | 2001 |
| Llugwy Ltd | Professional & scientific | 2026 |
| LM Creative Marketing Ltd | Administrative & support | 2016 |
| LMD Plastering Services Ltd | Construction | 2016 |
| LMI UK Finance Limited | Professional & scientific | 2025 |
| LMP Nutrition Consultancy Ltd | Health & social care | 2021 |
| LMS Creative Studios Limited | Other services | 2022 |
| LMS Express Ltd | Transport & logistics | 2019 |
| LNA AC Ltd | Manufacturing | 2025 |
| Lnba Advisory Limited | Professional & scientific | 2026 |
| LOA Finance Limited | Professional & scientific | 2019 |
| Loadlace Interiors Limited | Construction | 2005 |
| Loadquest Haulage Limited | Transport & logistics | 2025 |
| LOC Education Ltd | Education | 2024 |
| Loca Investments Ltd | Construction | 2025 |
| Local Panda Limited | Hospitality | 2026 |
| Loch Shin Camping Limited | Hospitality | 2019 |
| Lockfit ( Milton Keynes) Ltd | Construction | 2026 |
| Lockfit (C & W Contracts) Ltd | Construction | 2021 |