| Life Health Medical Ltd | Health & social care | 2022 |
| Life on Earth Ltd | Information & communication | 2020 |
| Lifecast Body Simulation Limited | Administrative & support | 2017 |
| Lifecast Limited | Arts & recreation | 2003 |
| Lifejacket Productions Ltd | Information & communication | 2023 |
| Light Fantastic Production Services Ltd | Professional & scientific | 2007 |
| Light Group Holdings Limited | Construction | 2016 |
| Light ME UP Consultancy Limited | Administrative & support | 2025 |
| Lighthouse Healthcare Group Limited | Professional & scientific | 2014 |
| Lighthouse Plumbing & GAS Ltd | Construction | 2024 |
| Lightstruck Digital Limited | Information & communication | 2013 |
| Lignereux Limited | Arts & recreation | 2013 |
| Lilly&Son Ltd | Construction | 2012 |
| Lily House Park Limited | Real estate | 2021 |
| Lily-Rose Haven Limited | Real estate | 2026 |
| Limay MOR, Legal Advisor Ltd | Professional & scientific | 2022 |
| Limbhoe Limited | Wholesale & retail | 2024 |
| Lime Communications Limited | Administrative & support | 1999 |
| Limerick Services Limited | Health & social care | 2016 |
| Limor Creative Ltd | Professional & scientific | 2025 |
| Linco Beauty Ltd | Health & social care | 2022 |
| Linco Estates Ltd | Real estate | 2022 |
| Linco Properties Ltd | Real estate | 2022 |
| Lincoln Court (Denham) Residents Limited | Households | 2005 |
| Lincoln Estates North East Ltd | Real estate | 2025 |
| Lincoln Plaza LLP | | 2013 |
| Linda Plant International Academy Limited | Information & communication | 2025 |
| Lindley's Electrical Services Ltd | Construction | 2019 |
| Lindy Transport LLP | | 2016 |
| Lineage Deliveries LLP | | 2016 |
| Lines & Lines Builders Ltd | Construction | 2021 |
| Lini Estates Ltd | Real estate | 2024 |
| Link Associates Ltd | Real estate | 2002 |
| Link Lettings Limited | Real estate | 2006 |
| Link Management Property Services Ltd | Real estate | 2025 |
| Link Property (UK) Ltd | Real estate | 2006 |
| Linkonect Limited | Wholesale & retail | 2004 |
| Lion Pictures Ltd | Information & communication | 2011 |
| Lionheart & Silk Ltd | Real estate | 2026 |
| Lipjan Car Wash Ltd | Administrative & support | 2022 |
| Lipoid Kosmetik Ltd | Wholesale & retail | 1982 |
| Liquefy Limited | Information & communication | 2007 |
| Liquid Construction Ltd | Arts & recreation | 2020 |
| Lisbonstudios Ltd | Arts & recreation | 2016 |
| Lisnovitch Limited | Health & social care | 2010 |
| Lisnovitch Property Investment Ltd | Real estate | 2019 |
| Litta App Limited | Water & waste | 2017 |
| Little Brown Cann Training and Consultancy Ltd | Professional & scientific | 2026 |
| Little by Little Productions Ltd | Extraterritorial | 2017 |
| Little Greenwood Ltd | Professional & scientific | 2013 |
| Little Life Ltd | Education | 2022 |
| Little London Branding Ltd | Professional & scientific | 2024 |
| Little MAN PUB Company Ltd | Hospitality | 2024 |
| Little Motivators Ltd | Education | 2023 |
| Little Red HEN Productions Limited | Information & communication | 2014 |
| Little Steps Home From Home Nursery Ltd | Health & social care | 2024 |
| Little Tots Ltd | Health & social care | 2025 |
| Little Treasures Nursery (UK) Limited | Education | 2003 |
| LIU Jones Associates LLP | | 2011 |
| Live Events & Proms Limited | Arts & recreation | 2019 |
| Live Lane Entertainment Limited | Other services | 2023 |
| Live Spiffy Ltd | Wholesale & retail | 2017 |
| Living East Three Limited | Real estate | 2024 |
| Living From Properties Ltd | Real estate | 2013 |
| Living Inspired Limited | Education | 2021 |
| LJM Business Services Ltd | Administrative & support | 2023 |
| LJN Properties Ltd | Real estate | 2020 |
| LJW Change Ltd | Professional & scientific | 2026 |
| LKB Fencing Limited | Construction | 2019 |
| LKS Trading Limited | Financial services | 2013 |
| LL Suites Ltd | Real estate | 2022 |
| LLG Pro Detailing Ltd | Other services | 2017 |
| Llgroup Limited | Financial services | 2023 |
| Llionaire Ltd | Wholesale & retail | 2020 |
| Lloyds & Casanove Investment Partners Limited | Administrative & support | 2002 |
| Lloyds Logistics Ltd | Wholesale & retail | 2024 |
| LM Group Ltd | Hospitality | 2017 |
| LM Smart Choice Solutions Ltd | Agriculture & fishing | 2025 |
| LM Tech Hub Limited | Information & communication | 2023 |
| LMN Restoration & Polishing Ltd | Construction | 2015 |
| LNA Cars Limited | Transport & logistics | 2025 |
| LNC Canine Club Ltd | Other services | 2024 |
| LND Media Ltd | Administrative & support | 2017 |
| Local Energy Markets Alliance Ltd | Extraterritorial | 2023 |
| Locus Coaching Ltd | Education | 2019 |
| Loebenberg Enterprises Ltd | Professional & scientific | 2014 |
| Loft Care Design and Build Limited | Construction | 2022 |
| Lofts of South London Ltd | Construction | 2019 |
| Logivox Ltd | Information & communication | 2025 |
| Logix Books Limited | Wholesale & retail | 2012 |
| Lohkal Group Ltd | Information & communication | 2024 |
| Loire Facilities LLP | | 2015 |
| Lola L Ltd | Real estate | 2019 |
| Lola’S Hairven Ltd | Information & communication | 2024 |
| Lomya Ltd | Professional & scientific | 2026 |
| London Air Conditioning Ltd | Energy | 2024 |
| London Beer GAS Limited | Wholesale & retail | 2001 |
| London Bride Limited | Wholesale & retail | 2010 |
| London Business Coach Limited | Professional & scientific | 2013 |
| London Business Conferences Group Ltd | Administrative & support | 2004 |