| Jannat Stores (Nelson) Limited | Wholesale & retail | 2023 |
| Japan Curated Ltd | Wholesale & retail | 2020 |
| Jattis Kitchen Limited | Hospitality | 2025 |
| Jaurah Hire and Storage Ltd | Administrative & support | 2018 |
| Jaxeo Limited | Wholesale & retail | 2023 |
| JB & RB Investments Ltd | Households | 2024 |
| JD Alliance Ltd | Wholesale & retail | 2025 |
| JD Brands Limited | Wholesale & retail | 2020 |
| JD Fashion Ltd | Wholesale & retail | 2014 |
| JD Upholstery Supplies (2007) Limited | Wholesale & retail | 2006 |
| JDF Homes Limited | Real estate | 2019 |
| Jefferson & Bond Solicitors Limited | Professional & scientific | 2018 |
| Jelly Banana Ltd | Information & communication | 2017 |
| Jennifer Dawson Ltd | Other services | 2012 |
| Jessica Aesthetics Limited | Other services | 2025 |
| JET Comms Group Holdings Limited | Information & communication | 2014 |
| JET Comms Holdco Limited | Financial services | 2020 |
| JET Comms Holdings Limited | Professional & scientific | 2000 |
| JET Comms Intermediate Holdings Limited | Professional & scientific | 2013 |
| JET Comms Pikco Limited | Professional & scientific | 2014 |
| JET Holdco Limited | Financial services | 2024 |
| JG Horizons Ltd | Construction | 2024 |
| JHF Consulting Ltd | Professional & scientific | 2026 |
| Jibba Jabba Limited | Information & communication | 2008 |
| Jiwa Estates Ltd | Real estate | 2021 |
| JJ Foods Bolton Ltd | Hospitality | 2019 |
| JLH Digital Ltd | Wholesale & retail | 2025 |
| JM Blades Ltd | Information & communication | 2018 |
| Jmdc Services Ltd | Professional & scientific | 2016 |
| JMF Design Services Limited | Professional & scientific | 2009 |
| Jmilliken Contractors Ltd | Construction | 2025 |
| JMW Motors Ltd | Wholesale & retail | 2025 |
| Joetry Limited | Wholesale & retail | 2019 |
| JOG Building Services Limited | Construction | 2012 |
| John Fury Limited | Arts & recreation | 2023 |
| John H. Cluley & SON Limited | Construction | 1975 |
| John KAY Developments Limited | Construction | 2001 |
| Johnny Maguire Limited | Information & communication | 2021 |
| Johnny's Online Services Ltd | Wholesale & retail | 2026 |
| Johnston Contractors Limited | Construction | 2003 |
| Jordan Communications Limited | Professional & scientific | 2006 |
| Jorge's Landscape & Gardening Services Limited | Administrative & support | 2025 |
| Joshgilron Limited | Hospitality | 2015 |
| JPR Electrical Contractors Limited | Construction | 2020 |
| JPR Installations (NW) Limited | Construction | 2026 |
| JR Accommodation Ltd | Real estate | 2019 |
| JR White Building Maintenance Ltd | Construction | 2024 |
| JS Window Blinds Ltd | Manufacturing | 2015 |
| JSR People Tech Ltd | Information & communication | 2017 |
| JTK Medicals Ltd | Health & social care | 2024 |
| Jude Automotive Logistics Ltd | Transport & logistics | 2026 |
| Juergenmaier Consulting Ltd | Professional & scientific | 2019 |
| Jules Care Limited | Health & social care | 2014 |
| Julie Dickson Fashion Styling Ltd | Other services | 2011 |
| Julie Miles Ceramics Ltd | Arts & recreation | 2011 |
| Julius Brighton Ltd | Professional & scientific | 2003 |
| Juno Cars Ltd | Wholesale & retail | 2025 |
| Justhussain Ltd | Health & social care | 2025 |
| JW Bartholomew and Sons Limited | Manufacturing | 2017 |
| JWC Building Contractors Ltd | Construction | 2018 |
| K a Curries Ltd | Hospitality | 2026 |
| K K Dewan Limited | Health & social care | 2010 |
| K. Jennick Limited | Construction | 2002 |
| K.S. Prestige Motors Limited | Wholesale & retail | 2026 |
| K2 Capital Group Ltd | Wholesale & retail | 2025 |
| Kaavish Ltd | Wholesale & retail | 2026 |
| Kairos Sports Limited | Wholesale & retail | 2026 |
| Kamala Halal Meat Ltd | Wholesale & retail | 2022 |
| Kansas Fried Chicken&Pizza Ltd | Hospitality | 2025 |
| Kanza Ltd | Health & social care | 2026 |
| Kapthorne Limited | Other services | 2020 |
| Kasbah Express Ltd | Hospitality | 2025 |
| Kaswah Halal Meat and Poultry Limited | Manufacturing | 2026 |
| Kathmandu Variety Foods Limited | Wholesale & retail | 2012 |
| Kaufland Local Limited | Wholesale & retail | 2025 |
| Kayi Biomedical Ltd | Health & social care | 2021 |
| Kaylen Property Services Ltd | Construction | 2001 |
| Kaysfood Limited | Hospitality | 2025 |
| KB Movers Ltd | Transport & logistics | 2025 |
| KD Fashion Gallery Ltd | Wholesale & retail | 2025 |
| KDM Digital Ltd | Professional & scientific | 2015 |
| Kebabish KO Ltd | Hospitality | 2024 |
| Keep Karing Healthcare Ltd | Health & social care | 2023 |
| Keith Walton Brickwork Limited | Construction | 1985 |
| Keith Walton Construction Company Limited | Construction | 1985 |
| Kelly Traffic Solutions Limited | Administrative & support | 2017 |
| Kelswick Vehicle Solutions Ltd | Wholesale & retail | 2025 |
| Kelz Kutz Ltd | Other services | 2003 |
| Kemvyl Limited | Wholesale & retail | 2012 |
| Kendrick Engineering Consultants Ltd | Professional & scientific | 2025 |
| Kenyon Court Management Company Limited | Real estate | 2007 |
| Kettlebell Seminars Ltd | Arts & recreation | 2009 |
| Key Properties Developers Ltd | Real estate | 2021 |
| Keyay Limited | Transport & logistics | 2016 |
| Keystone Construction Ltd | Construction | 2024 |
| Keystone Masonry Contractors Ltd | Construction | 2021 |
| KH Locum Ltd | Health & social care | 2025 |
| Khaalis Limited | Hospitality | 2023 |
| Khan Tyrez Ltd | Wholesale & retail | 2023 |
| Khari Shareef Tikka Ltd | Hospitality | 2025 |