| KIN & Co. Developments Ltd | Real estate | 2025 |
| Kingly College of Education Limited | Education | 2024 |
| Kings Court (Holland) Lessees Limited | Households | 1964 |
| Kings Logistics Services Ltd | Transport & logistics | 2025 |
| Kings Power Electrical Solutions Ltd | Construction | 2025 |
| Kitchener Engineering Ltd | Construction | 2017 |
| Kiteworld Limited | Wholesale & retail | 2002 |
| KK Essex Limited | Hospitality | 2025 |
| Kkcr Limited | Information & communication | 2007 |
| Klarners Coaches Limited | Transport & logistics | 2010 |
| Klarners Tours Limited | Administrative & support | 2010 |
| Knowledge Gateway Ltd | Education | 2025 |
| KOD Property Ltd | Other services | 2015 |
| Kolaz Limited | Hospitality | 2019 |
| Kore Capital Ltd | Wholesale & retail | 2022 |
| KP Group Ltd | Construction | 2014 |
| KP Haulage Ltd | Transport & logistics | 2016 |
| KPT Property Maintenance Ltd | Construction | 2026 |
| KRK Services Limited | Construction | 2018 |
| Krossroads (London) Ltd | Health & social care | 2018 |
| KS Imports Ltd | Real estate | 2021 |
| KSS Autos Ltd | Wholesale & retail | 2016 |
| Kudhail Estates Ltd | Real estate | 2021 |
| Kygrol Group Ltd | Manufacturing | 2024 |
| Kyte Commercial Services Ltd | Construction | 2023 |
| Kyte Home Maintenance and Upgrades Ltd | Construction | 2023 |
| L & B Transport Ltd | Transport & logistics | 2010 |
| L and L Consulting Services Limited | Professional & scientific | 2024 |
| L Co Building Ltd | Construction | 2019 |
| L J Lynch Accounting Limited | Professional & scientific | 2017 |
| L J Sullivan Ltd | Real estate | 2026 |
| L W F C & G Limited | Hospitality | 2000 |
| L&J Currell Limited | Financial services | 2017 |
| L&K Funeral Directors Ltd | Other services | 2017 |
| LA Secure Transport Ltd | Transport & logistics | 2024 |
| Lady of the Twizzle Ltd | Hospitality | 2018 |
| LAF Decorating Ltd | Construction | 2026 |
| Lamb & Co Holdings Ltd | Financial services | 2024 |
| Lamb & Co Lettings Limited | Real estate | 2022 |
| Lamb & Co Property Ltd | Real estate | 2012 |
| Lami Developments Limited | Real estate | 2025 |
| Land Purveyors Ltd | Administrative & support | 2025 |
| Lane Homes (Sherbro) Ltd | Construction | 2020 |
| Langtry Hotel Ltd | Hospitality | 2013 |
| Laundry Central Ltd | Other services | 2019 |
| Laurel Estates Limited | Real estate | 2026 |
| Laurel Healthcare Ltd | Health & social care | 2025 |
| Lavender Lane Nursery Ltd | Health & social care | 2025 |
| Lawrence Commerce Ltd | Wholesale & retail | 2026 |
| LB Kitchen Ltd | Hospitality | 2026 |
| LBR - Lukasz Body Repair Ltd | Wholesale & retail | 2025 |
| LCB Sharp Ltd | Wholesale & retail | 2022 |
| LDK Distribution Limited | Wholesale & retail | 2025 |
| LDK Ventures Ltd | Professional & scientific | 2017 |
| Leaflets Direct (U.K.) Limited | Professional & scientific | 2009 |
| Leap Event Management Limited | Professional & scientific | 2019 |
| Learning Tides Ltd | Information & communication | 2018 |
| Lebowski Ltd | Information & communication | 2026 |
| LED Zeppelin Limited | Professional & scientific | 1994 |
| Ledimesh Limited | Wholesale & retail | 2026 |
| LEE Wick Lane Livery Ltd | Agriculture & fishing | 2022 |
| Lee's Glass and Glazing Ltd | Construction | 2023 |
| Legacy Care Group Limited | Financial services | 2024 |
| Legej Healthcare Limited | Health & social care | 2024 |
| Lekky Services Limited | Transport & logistics | 2015 |
| Lendeko Limited | Transport & logistics | 2022 |
| Lennox UK Ltd | Manufacturing | 2001 |
| Leolex Limited | Hospitality | 2026 |
| Let's Refurb Limited | Real estate | 2021 |
| Letsuni Limited | Information & communication | 2005 |
| Letton Lettings Ltd | Real estate | 2024 |
| LEV Blauer Limited | Real estate | 2015 |
| LGA Cleaning Ltd | Administrative & support | 2020 |
| Light Projects Evolve Ltd | Construction | 2024 |
| Light Projects Revolve Ltd | Manufacturing | 2025 |
| Lillie Bells Boutique Ltd | Wholesale & retail | 2020 |
| Lime Trees Care Limited | Health & social care | 2014 |
| Lion Heating & Property Services Ltd | Construction | 2025 |
| Lion Point Jaywick Limited | Real estate | 2021 |
| Little BEE Homestore Ltd | Wholesale & retail | 2019 |
| Little'Uns Retail Ltd | Wholesale & retail | 2020 |
| Littlebury Gardens Management Ltd | Households | 2021 |
| Littleport Gables Ltd | Real estate | 2024 |
| LJI Bathrooms & Wetrooms Limited | Construction | 2015 |
| LLW (UK) Limited | Real estate | 2014 |
| Llwpmc Ltd | Real estate | 2015 |
| LM - Bathrooms Ltd | Construction | 2024 |
| LNC Motors Ltd | Wholesale & retail | 2015 |
| Locum Connect Limited | Health & social care | 2024 |
| Lodge Farm Produce Limited | Agriculture & fishing | 2022 |
| Logic Facility Management Ltd | Administrative & support | 2025 |
| Lola's Hair Boutique Ltd | Other services | 2018 |
| Lola's Legacy Dog Rescue CIC | Agriculture & fishing | 2024 |
| London Carpet Solutions Ltd | Wholesale & retail | 2022 |
| London Later Life Mortgage Company Ltd | Financial services | 2025 |
| London Nail and Beauty Services Limited | Other services | 2025 |
| Longhurst and Putt Productions Ltd | Arts & recreation | 2018 |
| Look Ventures Group Limited | Professional & scientific | 2023 |
| Lordsbrook Ltd | Hospitality | 2016 |
| Lorenzo Capital Ltd | Financial services | 2021 |