| JRC Support Services Limited | Administrative & support | 2025 |
| JSO Construction Limited | Information & communication | 2016 |
| JT Setting OUT Ltd | Construction | 2023 |
| JTH Property Limited | Real estate | 2026 |
| JTR Construction Ltd | Construction | 2025 |
| Judd PUB Co Limited | Hospitality | 2015 |
| Jules Beauty Limited | Other services | 2018 |
| Julnat Ltd | Real estate | 2022 |
| Just Birds Rescue C.I.C. | Agriculture & fishing | 2025 |
| Just Just the One Limited | Financial services | 2014 |
| Just LED Lighting Ltd | Wholesale & retail | 2015 |
| JW Padel Academy Limited | Education | 2026 |
| JWM Electrical Gosport Ltd | Construction | 2025 |
| JXC Properties Limited | Real estate | 2024 |
| K & K Decor Limited | Construction | 2002 |
| K & K Hire Limited | Transport & logistics | 1999 |
| K & R Electrical Limited | Construction | 2018 |
| K R Harrison Limited | Professional & scientific | 2013 |
| K&M Plumbing Ltd | Construction | 2018 |
| K.G.V Electrical Solutions Ltd | Construction | 2024 |
| K.R.H Investments Limited | Real estate | 2024 |
| K.R.R Recruitment Ltd | Construction | 2026 |
| Kailani Dance Company Ltd | Arts & recreation | 2022 |
| Kaizen AI Solutions Ltd | Information & communication | 2025 |
| Kalli Rose Accessories Ltd | Wholesale & retail | 2026 |
| Kamtoo Deli Limited | Hospitality | 2024 |
| Kangawoo Limited | Information & communication | 2026 |
| Kani̇resh Ltd | Hospitality | 2025 |
| Karisma Homes Ltd | Real estate | 2017 |
| Kasimani Consulting Limited | Information & communication | 2020 |
| Katherine Robertson Limited | Professional & scientific | 2014 |
| Kathys Seaside Treats Bakery Limited | Hospitality | 2025 |
| Katie Bakes Limited | Administrative & support | 2018 |
| Katies Vinyl Bar and Kitchen Limited | Hospitality | 2017 |
| Kavira Digital Ltd | Information & communication | 2026 |
| KB Training Ltd | Construction | 2023 |
| KC Cornish Retreat Ltd | Hospitality | 2024 |
| Kdle Holdings Limited | Financial services | 2024 |
| Kerberos Software Ltd | Information & communication | 2018 |
| Kestrel Property Limited | Real estate | 2018 |
| Ketchstone Ltd | Real estate | 2025 |
| Kewma Property Services Ltd | Households | 2024 |
| KFM Services Limited | Other services | 2021 |
| KG1228 Trading Ltd | Wholesale & retail | 2020 |
| Khadija Spice Ltd | Hospitality | 2025 |
| KIM Rose Jewellery Collection Ltd | Wholesale & retail | 2025 |
| Kind & Co HR Ltd | Administrative & support | 2025 |
| Kingfisher Caravan Park Limited | Hospitality | 2000 |
| Kingstone (South) Limited | Construction | 2025 |
| Kingswell Berney Limited | Professional & scientific | 2003 |
| KIWITEC68 Limited | Professional & scientific | 2023 |
| KJB Residential Property Management Limited | Households | 2020 |
| KLICK2 Logistics Limited | Transport & logistics | 2015 |
| Kluchy UK Ltd | Other services | 2018 |
| Kmes Packaging Supplies Ltd | Wholesale & retail | 2025 |
| KMT Auto Services Ltd | Wholesale & retail | 2021 |
| Knights Home Cinema Limited | Construction | 2000 |
| Knott Healthcare Limited | Health & social care | 2026 |
| Knott Kinetics Ltd | Health & social care | 2017 |
| KOFII29 Ltd | Hospitality | 2026 |
| Kondra Limited | Construction | 2025 |
| Kondra Studios Polygon SPV Limited | Hospitality | 2025 |
| Kora.Ai Limited | Information & communication | 2025 |
| Koufu Food Ltd | Hospitality | 2026 |
| KPS Electrical ( Hampshire) Ltd | Construction | 2023 |
| KR Bookkeeping Limited | Professional & scientific | 2019 |
| L & a UK Limited | Transport & logistics | 2001 |
| L & J'S Properties Limited | Real estate | 2017 |
| L Bishop Interiors Limited | Construction | 2004 |
| L&B Pascoe Limited | Construction | 2023 |
| L-Mark Harris Training Limited | Professional & scientific | 2022 |
| L.A. Tooling Limited | Manufacturing | 1978 |
| L.B.S. Pipework Services Limited | Construction | 2006 |
| L.F.D. Limited | Manufacturing | 1992 |
| LAK Refrigeration Ltd | Administrative & support | 2002 |
| Lamb’S Consulting Ltd | Professional & scientific | 2026 |
| Landscapes 4 Living Ltd | Administrative & support | 2015 |
| Landscaping (Southern) Ltd | Administrative & support | 2017 |
| Lane & Peach Limited | Construction | 2016 |
| Langrish Lettings Limited | Real estate | 2026 |
| Last Cast Saloon Fishing on Line Limited | Wholesale & retail | 2023 |
| Last Cast Saloon Fishing Supplies Ltd | Wholesale & retail | 2005 |
| Laura Jayne Hunter Ltd | Wholesale & retail | 2023 |
| Lavender Pearl Ltd | Professional & scientific | 2026 |
| Laverstock Limited | Real estate | 2021 |
| Lawi Barbers ( Gosport ) Ltd | Other services | 2026 |
| Lazenbury House Limited | Real estate | 2019 |
| Lazenbury Ltd | Real estate | 2000 |
| Lazenbury Property ( Lydia) Limited | Real estate | 2021 |
| Lazenbury Property (Bemisters & Park Parade) Limited | Real estate | 2019 |
| Lazenbury Property (Forton) Limited | Real estate | 2019 |
| Lazenbury Property (Stoke Road) Limited | Real estate | 2020 |
| Lazenbury Property Management Ltd | Real estate | 2018 |
| Lazenbury Woodland (IOW) Limited | Real estate | 2018 |
| Lazraf Properties Limited | Real estate | 2019 |
| LB Media Solutions Limited | Information & communication | 2025 |
| LC Inventory Services Limited | Administrative & support | 2013 |
| LD Property Management (Fareham) Ltd | Real estate | 2006 |
| LDA Plumbing Services Ltd | Construction | 2016 |
| LDL Property Services Ltd | Administrative & support | 2021 |