| Kolay Grill Limited | Hospitality | 2023 |
| Kongo Limited | Wholesale & retail | 2019 |
| Konstantin General Building Ltd | Construction | 2024 |
| Kontrol Automation Trading Limited | Construction | 2014 |
| Kool Kidz Club Limited | Education | 2018 |
| KOP Hill Estates Ltd | Real estate | 2025 |
| Kotechnology Limited | Information & communication | 2009 |
| Kottiyoor Company Limited | Health & social care | 2015 |
| KPS Hospitality Ltd | Hospitality | 2019 |
| KPS Wine Limited | Wholesale & retail | 2013 |
| Krama Consulting Limited | Professional & scientific | 2015 |
| KRG Property Investments Limited | Households | 2025 |
| Kripa Homes Limited | Real estate | 2024 |
| Kripa Traders Limited | Wholesale & retail | 2024 |
| Krishna-Keshari Limited | Health & social care | 2023 |
| Krystal Business Solutions Ltd | Transport & logistics | 2025 |
| KS Models LLP | | 2017 |
| KSJ Construction Limited | Construction | 2021 |
| KSL Holdings Limited | Real estate | 2016 |
| KTH Projects Limited | Wholesale & retail | 2016 |
| Kumby Ltd | Health & social care | 2022 |
| Kuramaison Limited | Wholesale & retail | 2026 |
| Kurrajong Engineering Services Ltd | Professional & scientific | 2019 |
| Kusina DE Manila Limited | Hospitality | 2023 |
| KW Services Pro Ltd | Wholesale & retail | 2025 |
| Kwaabbie Ltd | Real estate | 2025 |
| Kwashe Limited | Health & social care | 2012 |
| Kyko Services Ltd | Construction | 2024 |
| Kymley Limited | Professional & scientific | 2005 |
| KZZ Assessments Ltd | Health & social care | 2026 |
| L & J Drainage Limited | Water & waste | 2011 |
| L a Horgan Ltd | Construction | 2015 |
| L a Lawyers Limited | Professional & scientific | 2012 |
| L BEE Limited | Information & communication | 2019 |
| L C GAS Services Limited | Construction | 2025 |
| L E X Electrical Services Ltd | Construction | 2023 |
| L Hendry Solutions Ltd | Construction | 2021 |
| L J S Rail Limited | Professional & scientific | 2009 |
| L Mccullough Consultancy Limited | Professional & scientific | 2024 |
| L P and SON Limited | Other services | 2014 |
| L&J Estates Ltd | Real estate | 2017 |
| L&K Flat Roofing Specialists Limited | Construction | 2017 |
| L&S Maintenance and Cleaning Ltd | Other services | 2019 |
| L&S Repointing Ltd | Construction | 2020 |
| L. Haroon Limited | Health & social care | 2015 |
| L.B. Electrical Wholesale Distributors Limited | Wholesale & retail | 1992 |
| L.E.R. Properties Limited | Professional & scientific | 2008 |
| L2R Training Ltd | Education | 2024 |
| LA Dennis Ltd | Hospitality | 2021 |
| LA Dolce Pizza Catering Limited | Hospitality | 2025 |
| LA Fiesta Brands Limited | Administrative & support | 2024 |
| LA Healing Thai Massage Ltd | Other services | 2026 |
| LA Nova Bridal Limited | Wholesale & retail | 2024 |
| Laadi Golden Properties Limited | Real estate | 2020 |
| Labi Systematic Solutions Ltd | Professional & scientific | 2004 |
| Lacel Ltd | Information & communication | 2018 |
| LAD Property & Building Services Limited | Real estate | 2020 |
| Ladgate Solutions Ltd | Other services | 2022 |
| Lady Margaret Gardens Residents Association Limited | Households | 2013 |
| Lakes Carpentry and Builders Limited | Construction | 2014 |
| LAL Kila Companies Limited | Wholesale & retail | 2014 |
| Lamacraft Electrical Services Limited | Administrative & support | 2016 |
| Lamacraft Property Limited | Real estate | 2023 |
| Lambs Lane Ltd | Real estate | 2025 |
| Lamo Care Limited | Health & social care | 2014 |
| Lanai Outdoor Commercial Limited | Construction | 2017 |
| Lanava Studios Limited | Information & communication | 2025 |
| Lancin Ltd | Information & communication | 2012 |
| Landell Investments Limited | Real estate | 2006 |
| Landmark Chauffeurs Ltd | Transport & logistics | 2025 |
| Landmark Launderette Limited | Other services | 2024 |
| Landscape Futures C.I.C. | Professional & scientific | 2013 |
| Landscapewise Limited | Administrative & support | 2024 |
| Landsend Property Ltd | Construction | 2025 |
| Landshuttle Ltd | Extraterritorial | 2023 |
| Lane & Family Ltd | Construction | 2023 |
| Langa Rise Ltd | Professional & scientific | 2025 |
| Langford Trading Company Limited | Agriculture & fishing | 1995 |
| Langley Farm Management Co Ltd | Real estate | 2016 |
| Langley Garage (Stevenage) Limited | Wholesale & retail | 1960 |
| Langley View (Chulmleigh) Management Limited | Administrative & support | 2005 |
| Lansac Homes Limited | Construction | 2016 |
| Lansmith Global Partners Limited | Financial services | 2019 |
| Lapiz Holdings Ltd | Financial services | 2025 |
| LAPTOPS4CHANGE Ltd | Wholesale & retail | 2022 |
| Larchton Limited | Information & communication | 2018 |
| Larks Ridge Management Company Limited | Households | 1992 |
| Lary&Dumy Transport Limited | Transport & logistics | 2014 |
| Lash OUT by Chloe B Ltd | Wholesale & retail | 2020 |
| Last Minute Locum Solutions Limited | Administrative & support | 2023 |
| Later Life Matters Limited | Information & communication | 2026 |
| Latimer Green Residents Association Limited | Households | 1989 |
| Laundry Wish Ltd | Administrative & support | 2022 |
| Laura Brock Limited | Health & social care | 2023 |
| Laura Cameron’S Aesthetics Limited | Other services | 2022 |
| Laura Harvey Consulting Limited | Professional & scientific | 2025 |
| Lauren Palphreyman Limited | Information & communication | 2025 |
| Laurentian BIO Limited | Professional & scientific | 2025 |
| Lavender Court (Burridge) Management Company Limited | Households | 2002 |
| Lavinia Mary Caroline Day Ltd | Extraterritorial | 2023 |