| JTV Care Homes Limited | Health & social care | 2004 |
| JU9 Supply Ltd | Wholesale & retail | 2026 |
| Jubair Khan Limited | Construction | 2024 |
| Jubilee Generators Limited | Professional & scientific | 2025 |
| Jubilee Homes Ltd | Construction | 2016 |
| Judah Care Ltd | Health & social care | 2019 |
| Jude Properties Limited | Households | 2017 |
| Judge Construction Private Limited | Construction | 2022 |
| Judichi Care Limited | Health & social care | 2025 |
| Judicial CIC | Professional & scientific | 2018 |
| Jugmusic Ltd | Wholesale & retail | 2025 |
| Jugnee Ltd | Wholesale & retail | 2019 |
| Jugni Limited | Transport & logistics | 2022 |
| Jujhar 1 Limited | Real estate | 2019 |
| Julita Ltd | Professional & scientific | 2024 |
| Jumb Limited | Construction | 2025 |
| Jumbo Importers Limited | Wholesale & retail | 2017 |
| Junaid Khan Group Ltd | Other services | 2025 |
| Junaid Khan Limited | Other services | 2017 |
| Junction 7 Food and Beverage Limited | Wholesale & retail | 2025 |
| Junior Kids London Ltd | Wholesale & retail | 2026 |
| Junior Kids Wholesale Limited | Wholesale & retail | 2024 |
| Juniors Cafe & Softplay Limited | Hospitality | 2020 |
| Junkaway Solutions Limited | Water & waste | 2025 |
| Junsphil Limited | Health & social care | 2022 |
| Jurlina Ltd | Transport & logistics | 2014 |
| Juss Marketing Limited | Administrative & support | 2021 |
| Just 4 MEN Limited | Other services | 2023 |
| Just Builds Construction Limited | Construction | 2024 |
| Just Click Online Ltd | Wholesale & retail | 2025 |
| Just DAO IT Ltd | Information & communication | 2022 |
| Just Displays Limited | Other services | 2003 |
| Just Dsars Ltd | Information & communication | 2026 |
| Just Hire IT Ltd | Other services | 2023 |
| Just Like Momma's Ltd | Hospitality | 2019 |
| Just My Room Ltd | Real estate | 2016 |
| Just Quick Ltd | Wholesale & retail | 2022 |
| Just Sourcing Ltd | Wholesale & retail | 1996 |
| Justbeegorgeous Ltd | Other services | 2021 |
| Justgod Group Limited | Transport & logistics | 2021 |
| Justin Chauffeurs Ltd | Transport & logistics | 2020 |
| Justjutz Ltd | Wholesale & retail | 2026 |
| Jutek Trading Ltd | Manufacturing | 2014 |
| Jutt Karahi Ltd | Hospitality | 2025 |
| JV Construction Management Limited | Professional & scientific | 2015 |
| JV Global Services Ltd | Transport & logistics | 2025 |
| JV Properties Investments Ltd | Real estate | 2021 |
| JVD Group Limited | Real estate | 2015 |
| Jvohra Ltd | Information & communication | 2024 |
| JVR Consultancy Limited | Professional & scientific | 2011 |
| JW Building Finishers Southern Ltd | Construction | 2017 |
| JWB Technology Ltd | Information & communication | 1995 |
| JWP Services Ltd | Wholesale & retail | 2024 |
| JWZ Motors Ltd | Wholesale & retail | 2023 |
| JX3 Support Services Limited | Administrative & support | 2008 |
| Jyothi Limited | Real estate | 1986 |
| Jyo’S Touch Ltd | Construction | 2025 |
| JZB Solutions Ltd | Wholesale & retail | 2024 |
| Jzero Solutions Limited | Information & communication | 1996 |
| Jzrfood Ltd | Hospitality | 2026 |
| K & a Care Limited | Health & social care | 2007 |
| K & D Group Build Ltd | Construction | 2022 |
| K & J Carers Ltd | Health & social care | 2015 |
| K & M Contractors Limited | Other services | 2012 |
| K & N Supplies Ltd | Wholesale & retail | 2016 |
| K 4 Khana Limited | Hospitality | 2025 |
| K Cart Store Limited | Wholesale & retail | 2025 |
| K Furniture Outlet Ltd | Wholesale & retail | 2025 |
| K H Removals Ltd | Transport & logistics | 2019 |
| K J Cool Services Ltd | Construction | 2021 |
| K K London Investments Limited | Real estate | 2015 |
| K K Supplier Ltd | Transport & logistics | 2000 |
| K L O' Rourke Construction Limited | Construction | 2017 |
| K L O'Rourke Limited | Construction | 2005 |
| K M Lubtrans Ltd | Transport & logistics | 2019 |
| K Maan Construction Ltd | Construction | 2024 |
| K Nandha & Co Ltd | Professional & scientific | 2020 |
| K O Engineering Ltd | Wholesale & retail | 2015 |
| K Plumbing & Heating Ltd | Construction | 2022 |
| K S Consulting Limited | Professional & scientific | 2002 |
| K S Developments (Slough) Limited | Real estate | 2006 |
| K S J Consultancy Services London Limited | Information & communication | 2014 |
| K S Properties (Oxeney) Ltd | Real estate | 2025 |
| K S Properties (Slough) Ltd | Real estate | 2020 |
| K Singh and K Singh Properties Limited | Real estate | 2023 |
| K Star Construction Ltd | Construction | 2021 |
| K T Luxury Travels & Tours Ltd | Transport & logistics | 2024 |
| K T UK Retail Ltd | Wholesale & retail | 2024 |
| K TEC Tools Ltd | Administrative & support | 2015 |
| K&A Catering Limited | Hospitality | 2013 |
| K&Az Ltd | Information & communication | 2015 |
| K&B Installation Services Ltd | Construction | 2020 |
| K&B Screeding Ltd | Construction | 2019 |
| K&D Painting and Decorating Ltd | Construction | 2024 |
| K&E Groundworks Limited | Transport & logistics | 2025 |
| K&G (Hurst Farm) Limited | Health & social care | 2016 |
| K&J Builders UK Ltd | Construction | 2025 |
| K&M Aspire Limited | Education | 2024 |
| K&M Bellacare Ltd | Public administration | 2021 |
| K&M Homes & Investment Ltd | Real estate | 2025 |