| KL Creatives Studios CIC | Professional & scientific | 2026 |
| KL Cuts Barbershop Ltd | Other services | 2022 |
| KL Energy Limited | Energy | 2024 |
| KL Events Limited | Hospitality | 2025 |
| KL Media Holdings Ltd | Financial services | 2021 |
| KL Multimedia Limited | Information & communication | 2024 |
| KL Publications Ltd | Information & communication | 2016 |
| KL Youth News CIC | Education | 2026 |
| Klaid Construction Ltd | Construction | 2026 |
| Klcreativeholdings Ltd | Arts & recreation | 2025 |
| KLF Holdings Limited | Construction | 1984 |
| Klic Home Ltd | Construction | 2021 |
| Klic Partners Ltd | Construction | 2022 |
| Klic Recruitment Ltd | Administrative & support | 2017 |
| Klimatech Holdings Limited | Hospitality | 2018 |
| Klimatech Management Limited | Professional & scientific | 2014 |
| KLT Filtration Holdings Limited | Financial services | 2017 |
| KLT Filtration Limited | Manufacturing | 2011 |
| KLT Properties Holdings Limited | Financial services | 2017 |
| KLT Renewables Limited | Energy | 2017 |
| KMK Consultancy Limited | Professional & scientific | 2008 |
| Knight Fine Antiques & Collectables Ltd | Wholesale & retail | 2024 |
| Knight Passive Fire Ltd | Public administration | 2024 |
| Knights Holdings (Norwich) Ltd | Professional & scientific | 2024 |
| Knock-Clothes Ltd | Construction | 2023 |
| Knots Timber and DIY Limited | Wholesale & retail | 2026 |
| Koopowitz Consulting Ltd | Public administration | 2022 |
| Kota Chocolate Ltd | Manufacturing | 2021 |
| Kpar Management Ltd | Construction | 2022 |
| Kpar Properties Ltd | Real estate | 2025 |
| Kronus GB Limited | Wholesale & retail | 2010 |
| Kruzi Ltd | Manufacturing | 2024 |
| KSH Conservation Limited | Other services | 2016 |
| KW Development & Associates Ltd | Professional & scientific | 2017 |
| KW Legal Consulting Limited | Professional & scientific | 2025 |
| Kybernet Ltd | Wholesale & retail | 2012 |
| Kygn Properties Ltd | Real estate | 2022 |
| Kyushi Limited | Other services | 2016 |
| Kyushi Wellness Ltd | Health & social care | 2013 |
| L & a Installations Ltd | Construction | 2023 |
| L & O Windows Ltd | Construction | 2005 |
| L and R Properties (Norfolk) Ltd | Real estate | 2023 |
| L H Nahla Limited | Agriculture & fishing | 2025 |
| L J Shuardson Limited | Financial services | 2023 |
| L M Thomas Ltd | Professional & scientific | 2025 |
| L Sears Plumbing and Heating Limited | Construction | 2012 |
| L Symington Holdings Limited | Real estate | 2021 |
| L York Plumbing & Heating Limited | Construction | 2009 |
| L&Lh Contracts Ltd | Construction | 2023 |
| L. Symington (Farms) Limited | Agriculture & fishing | 1954 |
| LA Direct Limited | Manufacturing | 2017 |
| Lady Landscapers Ltd | Administrative & support | 2025 |
| Laing Access Platforms Limited | Wholesale & retail | 2016 |
| Lake Rail & Education Services Ltd | Transport & logistics | 2017 |
| Lakeside Stays Ltd | Hospitality | 2026 |
| Lambert Way Limited | Real estate | 2020 |
| Landles Auctioneers 1856 Ltd | Professional & scientific | 2013 |
| Langham Court Flats Company Limited | Households | 1981 |
| Langstaff Design Limited | Manufacturing | 2024 |
| Lantaur Ltd | Information & communication | 2018 |
| Lattice House Limited | Hospitality | 2026 |
| Lattice KL Ltd | Real estate | 2023 |
| Laulau Projects Limited | Real estate | 2017 |
| Laura Radford Photography Limited | Arts & recreation | 2013 |
| Laurane Limited | Professional & scientific | 2004 |
| Lavender Hill MOB Theatre Company | Arts & recreation | 2012 |
| Lavender House (Heacham) Management Co Limited | Households | 2001 |
| Lavish Estates Limited | Construction | 2013 |
| Lawrence (Timber) Ltd. | Manufacturing | 2015 |
| Laws Engineering Limited | Manufacturing | 2004 |
| Layman Media CIC | Information & communication | 2021 |
| LD Pristine Cleans Ltd | Administrative & support | 2025 |
| LDM Consultancy Limited | Professional & scientific | 2011 |
| LDR Physiotherapy ( Medlegal) Ltd | Health & social care | 2025 |
| Leaping Hare Renewables Ltd | Construction | 2020 |
| Learn in a Mini Limited | Education | 2009 |
| Leaside Court Owners Association Limited | Households | 2003 |
| LED Support Ltd | Information & communication | 2025 |
| Ledger and Stone Limited | Real estate | 2026 |
| Lee's Garden Machinery Services Ltd | Manufacturing | 2026 |
| Leesam Ltd | Wholesale & retail | 2011 |
| Leigh's Bees Limited | Agriculture & fishing | 2018 |
| Lemmon Industries Ltd | Real estate | 2018 |
| Lemon and Raspberry Limited | Manufacturing | 2017 |
| Lemon Zest Properties Limited | Real estate | 2005 |
| LEO and Lupus Ltd | Real estate | 2024 |
| Leonardi Group Ltd | Information & communication | 2025 |
| Lern Estates Limited | Real estate | 2025 |
| Let's GET Done Cleaning Ltd | Administrative & support | 2025 |
| Leveret Gardens Management Company Ltd | Households | 2018 |
| Lexham Estates Limited | Professional & scientific | 2010 |
| Lexpot Limited | Hospitality | 2012 |
| Leziate Drove Garage Ltd | Wholesale & retail | 2005 |
| LG Precision Plastering Ltd | Construction | 2026 |
| LI Sports Management Ltd | Arts & recreation | 2024 |
| Libando Limited | Professional & scientific | 2019 |
| Life With Support Housing Association Limited | Real estate | 2025 |
| Lighthouse Contract Limited | Construction | 2001 |
| Lighthouse Design and Marketing Ltd | Professional & scientific | 2010 |
| Lighthouse View Management Company Limited | Households | 1986 |