| LCA Book-Keeping Services Limited | Professional & scientific | 2016 |
| LCA Catering Ltd | Hospitality | 2015 |
| LCA Lights Camera Action Limited | Wholesale & retail | 1999 |
| Lchs Services Ltd | Wholesale & retail | 2019 |
| Lcuk High Wycombe Ltd | Other services | 2021 |
| LE Bouclier Ltd | Wholesale & retail | 2017 |
| LE Fevre Limited | Wholesale & retail | 1988 |
| LE Strange Services Ltd | Transport & logistics | 2004 |
| Lead Construction Ltd | Construction | 2016 |
| Lead the Charge Creative Ltd | Professional & scientific | 2023 |
| Leadbetter Removals Limited | Transport & logistics | 2015 |
| Leadership on the Go Limited | Professional & scientific | 2021 |
| Leadhook Media Ltd | Professional & scientific | 2021 |
| Leaf Catering Limited | Hospitality | 2025 |
| Leaf Market Access Ltd | Professional & scientific | 2025 |
| Leamington and Lulworth Estates Limited | Real estate | 1960 |
| Lean Punk Solutions Limited | Professional & scientific | 2019 |
| Leap Children's Therapy Limited | Health & social care | 2010 |
| Leaphar.Com Ltd | Other services | 2015 |
| Learn Healthy Living Ltd | Education | 2021 |
| Learn to Dance Limited | Education | 2011 |
| Leary CUE Sports Limited | Arts & recreation | 2010 |
| Leasehold Management Group Limited | Real estate | 2012 |
| Leather Soft Industries Ltd | Wholesale & retail | 2016 |
| Leatherland Europe Ltd | Wholesale & retail | 2019 |
| Leawood (Management) Company Limited | Extraterritorial | 1998 |
| Leci Group Ltd | Administrative & support | 2022 |
| Lectrical Solutions Limited | Construction | 2011 |
| Ledgers Affinity Limited | Professional & scientific | 2009 |
| LEE and Chester Properties Limited | Real estate | 2020 |
| LEE Young (London) Ltd | Real estate | 2009 |
| Lees of Bourne END Limited | Wholesale & retail | 2015 |
| Legacy Healthcare Services Limited | Health & social care | 2020 |
| Legacy Link Group Ltd | Financial services | 2026 |
| Legado Holdings Limited | Financial services | 2022 |
| Legends Carnival (GB) Ltd | Arts & recreation | 2026 |
| Legrandtruc Ltd | Information & communication | 2026 |
| Lehri Ltd | Real estate | 2023 |
| Lejards Limited | | 1986 |
| Lemain Garden Apartments (Management Company) Limited | Households | 2007 |
| Lemon Bricks Ltd | Real estate | 2025 |
| Lemon Studios Limited | Arts & recreation | 2014 |
| Lenkala Limited | Construction | 2019 |
| Leon 21 Ltd | Hospitality | 2022 |
| Leopard Executive Cars Ltd | Transport & logistics | 2010 |
| Lesson Moore Limited | Financial services | 2014 |
| Let's Talk Human Skills Ltd | Education | 2022 |
| Lets Go Coaches Limited | Transport & logistics | 2017 |
| Lets SEE Ltd | Hospitality | 2020 |
| Lets Talk: Addiction CIC | Education | 2025 |
| Letslearntech Limited | Education | 2025 |
| Letterbox Graphics Limited | Administrative & support | 1986 |
| Lettsconnect Ltd | Real estate | 2012 |
| Level UP Catering Ltd | Hospitality | 2024 |
| Leverloom Ltd | Information & communication | 2026 |
| Levitate Consultancy Ltd | Administrative & support | 2024 |
| Levlin Estates Limited | Real estate | 2023 |
| Lewin Consultancy Limited | Information & communication | 2022 |
| Lexy Construction Ltd | Construction | 2012 |
| Leygroves Ltd | Professional & scientific | 2006 |
| Leyton Building & Surveying Limited | Professional & scientific | 2013 |
| LFA Marketing Ltd | Professional & scientific | 2019 |
| LFG High Wycombe Limited | Wholesale & retail | 2007 |
| Liam Ioan Electrical Ltd | Construction | 2025 |
| Libby Watson Design Ltd | Professional & scientific | 2021 |
| Libby's Legacy Ltd | Administrative & support | 2025 |
| Libertatem Services Ltd. | Professional & scientific | 2014 |
| Liberty Films Entertainment Limited | Information & communication | 2008 |
| Liberty Support Solutions Limited | Information & communication | 2002 |
| Libertypact Limited | Wholesale & retail | 2021 |
| Librose Limited | Construction | 2007 |
| Lichen Properties Limited | Professional & scientific | 2008 |
| Lichen Renewal Limited | Water & waste | 2010 |
| Lief Designs Limited | Professional & scientific | 2002 |
| Life Balancer Ltd | Other services | 2022 |
| Life Build Employee Ownership Trustee Limited | Financial services | 2020 |
| Life Build Solutions Ltd | Construction | 2005 |
| Life Building Centre (LBC) | Extraterritorial | 2005 |
| Life Construction and Property Limited | Construction | 2004 |
| Life to YOU Ltd | Health & social care | 2019 |
| Life Transformations International | Other services | 2011 |
| Lifebalancelever Limited | Health & social care | 2024 |
| Lifestyle Windows and Doors Ltd | Extraterritorial | 2023 |
| Lifetime Assets Limited | Real estate | 2025 |
| Liff Holdings Limited | Professional & scientific | 1989 |
| Lift & Shift Skip Hire Limited | Extraterritorial | 2005 |
| LIFT2SKY Ltd | Transport & logistics | 2022 |
| Light Engineering Enterprises Ltd | Construction | 2009 |
| Light Experience Ltd | Other services | 2015 |
| Lightest Touch (HW) Ltd | Wholesale & retail | 2024 |
| Lighthouse Asset Management Ltd | Extraterritorial | 2013 |
| Lighthouse Consulting (IT) Limited | Information & communication | 2015 |
| Lignum Group Limited | Financial services | 2022 |
| Lignum Resilient Ltd | Professional & scientific | 2022 |
| LIK Kesarov Ltd | Transport & logistics | 2024 |
| Likesar Ltd | Transport & logistics | 2022 |
| Lilac Software Ltd | Information & communication | 2013 |
| Lillys Homecare &Support Limited | Health & social care | 2025 |
| Lily Gray Consulting Ltd | Wholesale & retail | 2022 |
| Lilyjoe Limited | Real estate | 2020 |