| IT ALL Started in Basil Street Limited | Real estate | 2023 |
| J & R Searle Property Ltd | Real estate | 2025 |
| J Henden Building Ltd | Construction | 2020 |
| J&D London Limited | Wholesale & retail | 2013 |
| J.W.A. Developments Limited | Construction | 2017 |
| J.W.A. Property Investments Limited | Construction | 2019 |
| JAB Dental Services Limited | Health & social care | 2019 |
| Jacobs Property Services Ltd | Construction | 2010 |
| Jacomelli Marketing Ltd | Professional & scientific | 2023 |
| Jamison Associates Ltd | Professional & scientific | 2023 |
| Jane Crawford Interiors Ltd | Professional & scientific | 2022 |
| Janov Limited | Information & communication | 2000 |
| Jdheritagewindows Ltd | Construction | 2025 |
| Jeff Patrick Electrical Ltd | Construction | 2013 |
| Jemima Vine Limited | Wholesale & retail | 2012 |
| Jeshemo Limited | Financial services | 2025 |
| JG Ortho Solutions Ltd | Professional & scientific | 2025 |
| Jhrf Solutions Ltd | Professional & scientific | 2023 |
| Jhrh Investments Ltd | Real estate | 2020 |
| JM Private Clients Limited | Financial services | 2019 |
| John Baker Consulting Limited | Information & communication | 2011 |
| John's Shed Limited | Wholesale & retail | 2024 |
| JON Treasure Tree Services Ltd | Agriculture & fishing | 2022 |
| JP Media Management Consultancy Ltd | Professional & scientific | 2017 |
| JP Property Holdings Limited | Professional & scientific | 2004 |
| JSG Commercial Services (UK) Ltd | Manufacturing | 2024 |
| JSG Plant Services Ltd | Manufacturing | 2020 |
| JTZ Home & SON Property Ltd | Construction | 2026 |
| Juneau Limited | Professional & scientific | 2016 |
| Just Roofing Specialists Ltd | Construction | 2021 |
| Jwtraffic Services Ltd | Construction | 2025 |
| K & P Countryside and Gardens Ltd | Other services | 2022 |
| K L Properties NE Ltd | Hospitality | 2021 |
| Kairogen Ltd | Other services | 2025 |
| Kajal Trading Ltd | Manufacturing | 2021 |
| Kalglass Ltd | Construction | 2001 |
| Kali Ātman Bhavanta Ltd | Administrative & support | 2025 |
| KC Accountancy Limited | Professional & scientific | 2006 |
| KD Property Management & Lettings Ltd | Real estate | 2022 |
| Keats Haslemere Limited | Real estate | 2009 |
| Kegarily Ltd | Wholesale & retail | 2025 |
| Kehinde Images Ltd | Administrative & support | 2016 |
| Kenwyn Estates Ltd | Real estate | 2016 |
| Keogh Associates Limited | Information & communication | 2015 |
| Kestryl Ltd | Information & communication | 2026 |
| Keét Advisory Ltd | Professional & scientific | 2024 |
| Khipu Asset Finance Advisor Limited | Financial services | 2018 |
| Khosa & Co Limited | Real estate | 2019 |
| KIM Phillips Ltd | Professional & scientific | 2024 |
| Kimber Communications Limited | Professional & scientific | 2007 |
| Kingsley Edge Services Ltd | Administrative & support | 2025 |
| Kintillo Ltd | Professional & scientific | 2019 |
| Kinvest Groupe Limited | Real estate | 2025 |
| Kira Wellness Ltd | Wholesale & retail | 2026 |
| Kircal Limited | Professional & scientific | 1998 |
| Kittiwake Investments Ltd | Financial services | 2014 |
| Kjiw Limited | Hospitality | 2015 |
| Knox Cropper Training & Consultancy Limited | Professional & scientific | 1996 |
| Knox Cropper Trustee Limited | Professional & scientific | 2002 |
| Kobeck Properties Ltd | Real estate | 2024 |
| Kohde Ltd | Professional & scientific | 2007 |
| Konstantine Films Ltd | Information & communication | 2024 |
| Kslr Developments Limited | Construction | 2023 |
| L & T Hand Car Wash Limited | Other services | 2025 |
| L&J Investments Limited | Real estate | 2019 |
| L2 Property Development Ltd | Construction | 2015 |
| L2 Property Limited | Real estate | 2012 |
| LA DRY Cleaning Ltd | Other services | 2023 |
| Lambourne Homes Limited | Construction | 2006 |
| Landscape Construction and Supplies Limited | Professional & scientific | 2016 |
| Laughs Last Limited | Professional & scientific | 2009 |
| Lava Recruitment Solutions Ltd | Administrative & support | 2012 |
| LBR Consultants Limited | Professional & scientific | 2022 |
| LC Properties NE Ltd | Administrative & support | 2017 |
| Lcrl Holdings Limited | Financial services | 2025 |
| Leach Coffee Shop & Wine Bar Ltd | Hospitality | 2018 |
| Leatherby Light Limited | Professional & scientific | 2009 |
| LEE Consultancy and Business Services Limited | Administrative & support | 2016 |
| Legacy Pour Ltd | Manufacturing | 2026 |
| Lets Go About Ltd | Transport & logistics | 2016 |
| Levium Limited | Professional & scientific | 2018 |
| LEX Limited | Administrative & support | 2013 |
| LEY Need Limited | Wholesale & retail | 2025 |
| LFH Limited | Professional & scientific | 2018 |
| Limeblue Limited | Arts & recreation | 1996 |
| Linchfield Ltd | Information & communication | 2018 |
| Line Action Ltd | Arts & recreation | 2011 |
| Lion Court Residents Association Limited | Households | 1984 |
| Lion CUB Clothing Ltd | Wholesale & retail | 2018 |
| Liphook Auto Services Ltd | Wholesale & retail | 2019 |
| Liphook Carpet Warehouse Limited | Wholesale & retail | 2016 |
| Liphook Road Investments Limited | Real estate | 2016 |
| Lisle Consulting Ltd | Health & social care | 2019 |
| Little Dunes Ltd | Arts & recreation | 2026 |
| Little Turtlesystems Ltd | Information & communication | 2025 |
| Liverton Ltd | Construction | 2020 |
| Livies Treasures Ltd | Wholesale & retail | 2024 |
| Lizzie Ridout Design Ltd | Other services | 2024 |
| Llanfair Hill Limited | Administrative & support | 2025 |
| LMD Projects Ltd | Construction | 2017 |