| Jgtech Limited | Wholesale & retail | 2025 |
| JHD (Nuneaton) Limited | Financial services | 2024 |
| JHE IT Limited | Information & communication | 2018 |
| Jhmotorservices Ltd | Wholesale & retail | 2019 |
| Jill Carnall Photography Limited | Professional & scientific | 2023 |
| Jill Lorriman Ltd | Education | 2015 |
| Jim's Fish Bar Ltd | Hospitality | 2025 |
| Jirel's E-Bazaar Ltd | Wholesale & retail | 2025 |
| JJ Construction & Civils Ltd | Construction | 2015 |
| JJP Scaffolding Services Limited | Construction | 2024 |
| Jjpc Holdings Limited | Water & waste | 2015 |
| JKA Products Limited | Wholesale & retail | 2016 |
| JKA Property Developments Limited | Real estate | 2020 |
| JKE (UK) Limited | Manufacturing | 2012 |
| JKN Advisory Ltd | Administrative & support | 2023 |
| JKP Property Mgmt Ltd | Real estate | 2019 |
| JKS Consulting Services Limited | Professional & scientific | 2025 |
| JLJ Cooling & Heating Services Ltd | Manufacturing | 2017 |
| JLP Technical Services Ltd | Professional & scientific | 2026 |
| JLY Jointing Ltd | Construction | 2025 |
| JMA Logistics Limited | Transport & logistics | 2012 |
| Jmagea Limited | Professional & scientific | 2012 |
| JMC Distribution Ltd | Wholesale & retail | 2026 |
| JMC Marketing (Midlands) Ltd | Administrative & support | 2009 |
| JMC Publications (Midlands) Limited | Information & communication | 2013 |
| Jmmta Properties Limited | Real estate | 2026 |
| JMR Europe Ltd | Wholesale & retail | 2025 |
| JO Bow’S Ltd | Other services | 2023 |
| Jobs in Science Limited | Administrative & support | 2013 |
| Jody Elphick Limited | Professional & scientific | 2022 |
| Joel Ghylfert Ltd | Construction | 2024 |
| John Bromfield & Company Ltd | Professional & scientific | 2003 |
| John Igoe Properties Ltd | Real estate | 2026 |
| John Phillips Design Limited | Manufacturing | 1999 |
| John's Hair Design Ltd | Other services | 2012 |
| John. F. White Limited | Manufacturing | 1984 |
| Johnny Signs Ltd | Manufacturing | 2024 |
| Jokind Ltd | Health & social care | 2023 |
| JON Martin (Architectural) Limited | Manufacturing | 1994 |
| Jonathan&Robert Transport Ltd | Transport & logistics | 2025 |
| Jones and Jones Estates Management Ltd | Real estate | 2026 |
| Jones Farm Supplies Limited | Real estate | 1977 |
| Jones Site Services & Installations Ltd | Construction | 2023 |
| Jonspeed Limited | Wholesale & retail | 2005 |
| Jordan D Transport Ltd | Transport & logistics | 2024 |
| Josee Consulting Ltd | Information & communication | 2022 |
| Joseph Stapleton Osteopath's Limited | Health & social care | 2015 |
| Joshua Robert Homes (Lilbourne) Ltd | Construction | 2025 |
| JP Krol Limited | Construction | 2014 |
| JP Property (2021) Limited | Real estate | 2021 |
| JP2003 Ltd | Construction | 2026 |
| JPK Investment Group Limited | Real estate | 2026 |
| JPS Washroom Installers Limited | Construction | 2007 |
| JPW Maintenance Limited | Manufacturing | 2007 |
| JR13 Limited | Professional & scientific | 2018 |
| JRB Groundworks Ltd | Construction | 2026 |
| Jrcp Ltd | Construction | 2024 |
| Jrdg Ltd | Wholesale & retail | 2017 |
| JRO Construction Limited | Construction | 2014 |
| JS Coates Wedding Photography Limited | Other services | 2019 |
| JS Coventry Ltd | Other services | 2025 |
| JSC Logistics Ltd | Transport & logistics | 2025 |
| JSE Scaffold and Access Ltd | Construction | 2025 |
| Jskpv Ltd | Real estate | 2022 |
| JSP Invest Ltd | Real estate | 2025 |
| Jss&I Property Holdings Ltd | Construction | 2023 |
| Jssv Ltd | Health & social care | 2015 |
| JSW Watches Ltd | Wholesale & retail | 2023 |
| Julandy Holdings Ltd | Administrative & support | 2025 |
| Julandy Property Services Ltd | Real estate | 2025 |
| JULIAN72TRANS Ltd | Transport & logistics | 2016 |
| Julie Price and Co (Holdings) Limited | Real estate | 2013 |
| Junior Fitness Squad Ltd | Arts & recreation | 2021 |
| Junpat Ltd | Information & communication | 2026 |
| Jupiter UN Limited | Wholesale & retail | 2025 |
| Jury Place (Warwick) Limited | Real estate | 2019 |
| Just a Ride Ltd | Transport & logistics | 2024 |
| Just JAP Imports Limited | Wholesale & retail | 2018 |
| Just Properties Letz Ltd | Real estate | 2024 |
| Just Touching Base Ltd | Wholesale & retail | 2025 |
| Justar Security Ltd | Administrative & support | 2025 |
| Justcase Ltd | Wholesale & retail | 2023 |
| JV Grape UK Ltd | Construction | 2022 |
| JW Supply Ltd | Wholesale & retail | 2023 |
| K & F Properties Limited | Real estate | 1994 |
| K D M Haulage Ltd | Transport & logistics | 2018 |
| K L Cleaning Limited | Administrative & support | 2020 |
| K M Prototypes & Production Limited | Professional & scientific | 2014 |
| K Smith Construction Limited | Construction | 2014 |
| K Square Associates Ltd | Professional & scientific | 2024 |
| K&M Houses Ltd | Real estate | 2019 |
| K.D. Wright Electrical Services Ltd | Construction | 2002 |
| K.E.R.R. Company Holdings Limited | Hospitality | 2022 |
| K.Lipas & Daughter Limited | Administrative & support | 2015 |
| K.S.D. (Haulage Contractors) Limited | Water & waste | 1987 |
| K.S.M. Contractors Ltd | Construction | 2015 |
| K14N Properties Limited | Real estate | 2021 |
| KA Alterations Ltd | Other services | 2020 |
| Kabral Ltd | Transport & logistics | 2016 |
| Kagus Group Ltd | Extraterritorial | 2016 |