| Juganaru Builders Ltd | Construction | 2025 |
| Juggernaut Thinking Ltd | Professional & scientific | 2025 |
| Jugoist Ltd | Manufacturing | 2026 |
| Juice and Roast Ltd | Hospitality | 2026 |
| Juicy Buns Ltd | Hospitality | 2025 |
| Juktorajjyo Jalalabad Association Ltd | Other services | 2024 |
| Julian Trans Ltd | Transport & logistics | 2019 |
| Julian&Johnny Ltd | Transport & logistics | 2019 |
| Julicargo Ltd | Transport & logistics | 2026 |
| Juliets Hair and Cosmetics Ltd | Wholesale & retail | 2021 |
| Julimoss Limited | Administrative & support | 2015 |
| Julli Jets Ltd | Transport & logistics | 2025 |
| Juls Studio Ltd | Professional & scientific | 2023 |
| July Trans Ltd | Transport & logistics | 2023 |
| Jumade Ltd | Health & social care | 2023 |
| Jumbo Builders Ltd | Construction | 2025 |
| Jumping J'Ollies Ltd | Health & social care | 2024 |
| Junaid Chaudhri Ltd | Administrative & support | 2016 |
| June Battista Ltd | Construction | 2025 |
| Jungleboy Ltd | Wholesale & retail | 2020 |
| Juniorforge Ltd | Information & communication | 2026 |
| Juniper Pianos Limited | Other services | 2006 |
| JUR UK Ltd | Wholesale & retail | 2023 |
| JUS GAV Ltd | Transport & logistics | 2025 |
| Jusna & Co Limited | Transport & logistics | 2022 |
| Just Airport Cars Limited | Transport & logistics | 2023 |
| Just Branded Ltd | Financial services | 2022 |
| Just Car Hire Ltd | Transport & logistics | 2015 |
| Just Cash Limited | Real estate | 2004 |
| Just Civils & Concrete Limited | Construction | 2015 |
| Just Clean MK Ltd | Administrative & support | 2020 |
| Just Concrete Payroll Limited | Professional & scientific | 2019 |
| Just Curry Limited | Hospitality | 2017 |
| Just Fibre Ltd | Construction | 2021 |
| Just Fixed IT Ltd | Other services | 2021 |
| Just G Chesterfield Limited | Hospitality | 2013 |
| Just G Limited | Financial services | 2013 |
| Just Gaga Limited | Wholesale & retail | 2006 |
| Just IP Limited | Professional & scientific | 2013 |
| Just Jollof Spot Ltd | Hospitality | 2024 |
| Just Listen Clinics Limited | Health & social care | 2024 |
| Just Renting Limited | Real estate | 2006 |
| Just UK Mortgages Ltd | Financial services | 2024 |
| Justice for Minors International Ltd | Public administration | 2024 |
| JVDA12 Ltd | Real estate | 2026 |
| JW Plumbing Services Ltd | Construction | 2022 |
| JW Property Holdings Ltd | Real estate | 2022 |
| JWB Educational Psychology Services Ltd | Information & communication | 2016 |
| JWC Consulting Limited | Professional & scientific | 2008 |
| JWK Engineering Limited | Information & communication | 2014 |
| JXD Group Ltd | Professional & scientific | 2026 |
| JXI Construction Limited | Construction | 2017 |
| JXI Developments Ltd | Construction | 2025 |
| JY Supplies Ltd | Wholesale & retail | 2023 |
| Jykim Ltd | Health & social care | 2019 |
| JZH Transport Limited | Transport & logistics | 2018 |
| Jägsan Koray Ltd | Wholesale & retail | 2023 |
| K & a Building Contractors Ltd | Construction | 2025 |
| K & G Business Ltd | Wholesale & retail | 2017 |
| K & I Events Ltd | Hospitality | 2018 |
| K & I Property Investors Ltd | Real estate | 2022 |
| K & L Motor Supplies Limited | Wholesale & retail | 2003 |
| K a Foods Ltd | Hospitality | 2026 |
| K a P Electrical Limited | Construction | 2022 |
| K Aulakh Construction Service Ltd | Construction | 2024 |
| K Autos and Recoveries Limited | Wholesale & retail | 2025 |
| K Clancy Builders Limited | Construction | 2004 |
| K D Hawes Limited | Wholesale & retail | 1986 |
| K D Screeding Ltd | Construction | 2015 |
| K E Builders Limited | Construction | 2025 |
| K F Films Limited | Information & communication | 2022 |
| K F Horn Building Contractors Limited | Construction | 2005 |
| K F Maintenance Services Ltd | Construction | 2020 |
| K H M1 Limited | Construction | 2020 |
| K K Security Ltd | Administrative & support | 2015 |
| K K Tattooz Ltd | Arts & recreation | 2026 |
| K Lleshi Plumbing and Heating Ltd | Construction | 2015 |
| K Motor Services Ltd | Wholesale & retail | 2020 |
| K P Removals Ltd | Water & waste | 2021 |
| K S Services (Slough) Limited | Other services | 2006 |
| K Shortt & Co Limited | Construction | 2018 |
| K the Stylist Ltd | Wholesale & retail | 2025 |
| K&A Property Investors Ltd | Real estate | 2025 |
| K&Al Property Ltd | Real estate | 2025 |
| K&D Brothers Empire Limited | Construction | 2024 |
| K&E Brickwork Limited | Construction | 2020 |
| K&K Protection Limited | Administrative & support | 2022 |
| K&M Accountants Ltd | Professional & scientific | 2011 |
| K&M Builders & Developers Limited | Real estate | 2020 |
| K&N Cars Ltd | Wholesale & retail | 2025 |
| K&N Limited | Wholesale & retail | 2025 |
| K&S Essential Services Ltd | Construction | 2023 |
| K&S Supreme Ltd | Wholesale & retail | 2018 |
| K&S UK Properties Limited | Real estate | 2019 |
| K&Y Property Holding Ltd | Real estate | 2022 |
| K'S Island Flavours Ltd | Hospitality | 2023 |
| K-Motor Sales Limited | Wholesale & retail | 2012 |
| K-Noor Co Ltd | Transport & logistics | 2024 |
| K-Zed (Holdings) Ltd | Households | 2021 |
| K. Hertz Logistics Ltd | Administrative & support | 2020 |