| Joker Tattoo Portsmouth Ltd | Other services | 2025 |
| Jokers Barber Ltd | Other services | 2023 |
| Jolly Taxpayer Ltd | Hospitality | 2009 |
| JON Kercher Roofing Ltd | Construction | 2020 |
| JON Patrick Ltd | Professional & scientific | 2022 |
| Jones J Ltd | Education | 2025 |
| Jones Wear Ltd | Wholesale & retail | 2026 |
| Jordan's Property Group Limited | Real estate | 2023 |
| Jordec Property Services Limited | Construction | 2006 |
| Jorgen Games Ltd | Information & communication | 2019 |
| Josie D’Vaz Aesthetic Skin Clinic Ltd | Other services | 2024 |
| Jowa Enterprises Ltd | Information & communication | 2023 |
| Joy Charminster Ltd | Hospitality | 2012 |
| Joyce and Sons Builders Ltd | Construction | 2023 |
| Joyce Upholstery & Interiors Limited | Other services | 2026 |
| JP Building Services Inc Ltd | Construction | 2021 |
| JP Doors Contracting Ltd | Construction | 2024 |
| JP Group Company Holdings Ltd | Wholesale & retail | 2016 |
| JP Home Improvements Ltd | Construction | 2019 |
| JP Self Storage Limited | Transport & logistics | 2022 |
| JPB Blinds & Shutters Ltd | Other services | 2022 |
| Jpgp Ltd | Financial services | 2022 |
| JPH Plumbing and Heating Limited | Construction | 2022 |
| JPI (Hampshire) Limited | Construction | 2019 |
| JPJ Healthcare Limited | Health & social care | 2025 |
| JQM Property Ltd | Real estate | 2011 |
| JR Castro Company Ltd | Health & social care | 2014 |
| JR Developments Southern Limited | Construction | 2022 |
| JR Marketing Ltd | Wholesale & retail | 2019 |
| JR Properties South Ltd | Real estate | 2025 |
| JR Property Rental Ltd | Extraterritorial | 2022 |
| JR Spanners Ltd | Wholesale & retail | 2024 |
| JRA Kitchens Ltd | Manufacturing | 2026 |
| JRF Lettings Ltd | Hospitality | 2024 |
| JRG Sound & Light Limited | Arts & recreation | 2016 |
| JRK Timber Ltd | Wholesale & retail | 2025 |
| Jrpm Engineering Ltd | Administrative & support | 2015 |
| JRS Properties (South) Ltd | Real estate | 2022 |
| JS Finance Management Ltd | Professional & scientific | 2009 |
| Jsbs Globalwave Ltd | Wholesale & retail | 2025 |
| Jscc Investments Ltd | Real estate | 2021 |
| JSD Electrical Limited | Construction | 2016 |
| JSI Plastering and Drylining Contractors Ltd | Construction | 2023 |
| JSI Property Investments Limited | Real estate | 2024 |
| JSM Daycentres Ltd | Administrative & support | 2017 |
| Jssco UK Ltd | Wholesale & retail | 2015 |
| JT Everything Limited | Arts & recreation | 2021 |
| JT Garden and Landscape Services Limited | Administrative & support | 2026 |
| JT Healthcare Limited | Health & social care | 2012 |
| JT Pipe Fitting Services Ltd | Construction | 2014 |
| JT Plumbing and Renewables Ltd | Construction | 2018 |
| JTA Decorators Limited | Construction | 2019 |
| JTA Events Limited | Arts & recreation | 2020 |
| JTD Interiors Ltd | Construction | 2018 |
| JTH IOW Limited | Professional & scientific | 2024 |
| JTL Events Limited | Arts & recreation | 2024 |
| Jtmp Moling and Water Supply Services Limited | Construction | 2022 |
| JTN Holdings Limited | Administrative & support | 2025 |
| JTP Property Management Ltd | Real estate | 2023 |
| Jtreynolds Properties Ltd | Real estate | 2020 |
| JTS Property Maintenance Ltd | Construction | 2024 |
| Jubani Properties Ltd | Real estate | 2011 |
| Jubilee Construction Limited | Construction | 2008 |
| Jude Lucas Ltd | Professional & scientific | 2021 |
| Judwaa Consulting Ltd | Professional & scientific | 2018 |
| JULIA50 Ltd | Extraterritorial | 2016 |
| Julie Zone Ltd | Wholesale & retail | 2025 |
| Jump-Start Education Ltd | Education | 2026 |
| June 5 Limited | Professional & scientific | 2025 |
| Jungle London Limited | Other services | 2020 |
| Junior Dairy Limited | Wholesale & retail | 2015 |
| Jurali Limited | Real estate | 2022 |
| Just Automotive (South) Ltd | Wholesale & retail | 2026 |
| Just Clean Cleaning Ltd | Administrative & support | 2020 |
| Just Good Company Ltd | Health & social care | 2019 |
| Just Henley Roofing Limited | Construction | 2023 |
| Just Your Way Ltd | Health & social care | 2023 |
| Justasia Group Limited | Hospitality | 2024 |
| Justhemis Ltd | Information & communication | 2025 |
| Juvitech Limited | Wholesale & retail | 2024 |
| Juwa Limited | Administrative & support | 2025 |
| JVE Holdings Limited | Real estate | 2021 |
| JVE Investments Ltd | Real estate | 2020 |
| JW Electrical Services Portsmouth Ltd | Professional & scientific | 2011 |
| Jwdl Limited | Construction | 2017 |
| JWM Construction Consultants Ltd | Professional & scientific | 2020 |
| JWS Marine Services Limited | Manufacturing | 2004 |
| K & a Riley Limited | Other services | 1994 |
| K & a Travel Limited | Administrative & support | 2023 |
| K & E Care Limited | Health & social care | 2015 |
| K & G Equipment Rentals Limited | Administrative & support | 2022 |
| K & J Knight Tunnelling Ltd | Mining & quarrying | 2013 |
| K & J UK Investments Limited | Financial services | 2024 |
| K & R Assets Limited | Wholesale & retail | 2002 |
| K & W Electrical Services Limited | Construction | 2011 |
| K & W South Coast Holdings Limited | Financial services | 2026 |
| K B Management Solutions Limited | Professional & scientific | 2011 |
| K Frith Ltd | Manufacturing | 2018 |
| K Howard Holdings Ltd | Real estate | 2018 |
| K J Advice Services Ltd | Financial services | 2026 |