| Kingdom Executive Cars Limited | Transport & logistics | 2006 |
| Kingfisher Colours Limited | Manufacturing | 1980 |
| Kingfishers Limited | Extraterritorial | 2005 |
| Kinghorn Park (Nature Reserve) Residents Association Limited | Extraterritorial | 1994 |
| Kinross Enterprises Limited | Arts & recreation | 1983 |
| Kinzere Limited | Agriculture & fishing | 2005 |
| Kirk Rice Accountants Limited | Extraterritorial | 2007 |
| Kirk Rice Financial Services Limited | Extraterritorial | 2007 |
| Kiss Less Frogs Limited | Information & communication | 2007 |
| Kloc Digital Solutions Limited | Information & communication | 2005 |
| Komalware (UK) Limited | Real estate | 2004 |
| Koru Associates Limited | Professional & scientific | 2003 |
| Krass Limited | Professional & scientific | 2003 |
| KSL Consulting Limited | Professional & scientific | 2005 |
| Kubos Limited | Information & communication | 2005 |
| L.J.S Learning Limited | Administrative & support | 2006 |
| Laddon Properties Limited | Financial services | 1948 |
| Lakefield Holdings Limited | Wholesale & retail | 2001 |
| Lakefield Operations Limited | Extraterritorial | 1997 |
| Lakefield Productions Limited | Wholesale & retail | 1984 |
| Lakemill Investments Limited | Wholesale & retail | 1999 |
| Lakeview Property Developments Limited | Extraterritorial | 1982 |
| Lakeview Residents Company Limited | Households | 1994 |
| Land & Scales Accountancy Services Ltd | Information & communication | 2004 |
| Landacre Consultants Limited | Professional & scientific | 2002 |
| Landson Properties Limited | | 1961 |
| Larkfield Residents Management Company Limited | Households | 2002 |
| Larkspur Chase (Bracknell) Management Company Limited | Extraterritorial | 1998 |
| Latin Link | Other services | 1993 |
| Lattice Public Relations Limited | Professional & scientific | 2004 |
| Lavender Green Limited | Agriculture & fishing | 1994 |
| LAWN3 Limited | Professional & scientific | 2000 |
| Laws Associates Limited | Professional & scientific | 2002 |
| LEA Healthcare Ltd | Health & social care | 2014 |
| Leading Minds Limited | Education | 2005 |
| Learning With Alibi Limited | Education | 2008 |
| Lednock Ltd | Information & communication | 2012 |
| Leeda Limited | Extraterritorial | 1974 |
| Leeda Tackle Limited | Extraterritorial | 1994 |
| Leeracedriver.Com Ltd | Arts & recreation | 2004 |
| Lemarate Limited | Hospitality | 2002 |
| Leopard Couriers Limited | | 1988 |
| Lestac Services Limited | Information & communication | 2007 |
| Let's Talk Fresh Limited | Professional & scientific | 2000 |
| Leverstock Limited | Information & communication | 2003 |
| Lewis Property Rentals Ltd | Real estate | 2021 |
| Life Adventures Limited | Professional & scientific | 2016 |
| Lifescience Dynamics Limited | Administrative & support | 2004 |
| Light Obsession Ltd | Professional & scientific | 2002 |
| Lightsaber Services Ltd | Professional & scientific | 2018 |
| Lime Grove Management Limited | Households | 1997 |
| Linden Germany a Limited | Financial services | 1994 |
| Linden Germany B Limited | Financial services | 1994 |
| Lindores House (Holyport) Management Company Limited | Households | 1991 |
| Linehan Brothers Limited | Administrative & support | 2003 |
| Link Subsidiary Limited | Real estate | 2025 |
| Links Ventures Limited | Health & social care | 2002 |
| Lintec Europe (UK) Limited | Manufacturing | 1993 |
| Liquid Lands Ltd | Information & communication | 2021 |
| Liquid Leisure Limited | Arts & recreation | 2002 |
| Little Pier Limited | Real estate | 2007 |
| Little Trees Europe Limited | Extraterritorial | 1988 |
| Lloyds Pharmaceuticals | Professional & scientific | 1942 |
| Lmdc Group Limited | Financial services | 2021 |
| Logan Louw Leroux Limited | Professional & scientific | 2007 |
| Loman Holbrooke O'Neill Limited | Financial services | 2000 |
| Longreach Interiors Limited | Construction | 2010 |
| Lonza Biologics PLC | Other services | 1992 |
| Lonza Group UK Ltd | Financial services | 1990 |
| Lotwillow Limited | Information & communication | 1988 |
| Loud-N-Clear.Com Limited | Information & communication | 1999 |
| Lovedale Homes Limited | Real estate | 2020 |
| Loxwood Close Management Company Limited | Households | 2001 |
| LPF Ventures Limited | Real estate | 2017 |
| Luckley House Enterprises Limited | Real estate | 2000 |
| Luckley House School Limited | Education | 1973 |
| Ludgrove Pension Trustee Limited | Financial services | 2006 |
| Ludgrove School Trust Limited | Education | 1972 |
| Lushglen Limited | Manufacturing | 1996 |
| LY MEP Building Services Consultants Limited | Administrative & support | 2005 |
| Lynch Services Limited | Professional & scientific | 2004 |
| Lynden Hill Clinics Limited | Health & social care | 1993 |
| Lynwood Ealing Property Investment Co.Limited | Real estate | 1964 |
| M & C Services UK Ltd | Administrative & support | 2003 |
| M & M Mortgage Management Limited | Administrative & support | 2003 |
| M L Hobbs Limited | Construction | 2002 |
| M.B.Spencer Limited | Professional & scientific | 2006 |
| M.B.W. (Heathrow) Limited | Information & communication | 2006 |
| M.C.B. Dewatering Limited | Construction | 2003 |
| M.M.L. Systems Limited | Information & communication | 1978 |
| M.R.H. (Designs) Limited | Construction | 1999 |
| M.S Carpets (UK) Limited | Wholesale & retail | 2004 |
| M.V.Church (Sheet Metal) Limited | | 1991 |
| M/S Adviser Ltd | Professional & scientific | 2023 |
| Mabuhay Accountancy Services Limited | Professional & scientific | 1996 |
| MAC Plastering Services Ltd | Construction | 2015 |
| Mace Incorporated Limited | Administrative & support | 2003 |
| Macgowan Consultancy Limited | Professional & scientific | 1999 |
| Macgregor Radio Control Limited | Extraterritorial | 1985 |
| Madisan Technologies Limited | Information & communication | 2007 |