| John Cooper Projects Limited | Construction | 2009 |
| John Driver Limited | Transport & logistics | 2016 |
| John Duffy Ltd | Construction | 2023 |
| John Gordon International Limited | Administrative & support | 1980 |
| John Hagenstede Sound Limited | Information & communication | 2015 |
| John Henry's Catering Limited | Hospitality | 2024 |
| John Horsley Ltd | Information & communication | 2014 |
| John Kirk Supplies Limited | Wholesale & retail | 1981 |
| John Richee J.R Limited | Other services | 2014 |
| John Services Driver Ltd | Transport & logistics | 2017 |
| Johnpetriuc Ltd | Construction | 2014 |
| Johnson a K Ltd | Professional & scientific | 2016 |
| Johnson Commercials Limited | Wholesale & retail | 2015 |
| Johnson Park Homes Limited | Real estate | 2015 |
| Johny & Adriana Ltd | Construction | 2015 |
| Johny Builders Ltd | Construction | 2021 |
| Join Branch Ltd | Professional & scientific | 2023 |
| Join Tours UK Ltd | Wholesale & retail | 2017 |
| Jointel Consulting Limited | Information & communication | 2020 |
| Jokar Home Design Ltd | Wholesale & retail | 2025 |
| JOL Construction Services Ltd | Construction | 2026 |
| Jolee Holdings Limited | Financial services | 2021 |
| Jolipompon Limited | Wholesale & retail | 2017 |
| Jollein UK Ltd | Wholesale & retail | 2023 |
| Jolly Eximers Ltd | Wholesale & retail | 2024 |
| Jolly Properties Limited | Real estate | 2001 |
| Jolt UK Limited | Wholesale & retail | 2024 |
| Jomar Holdings Limited | Financial services | 2018 |
| Jomerrick Productions Limited | Information & communication | 2026 |
| Jomirow IT Services Ltd | Information & communication | 2025 |
| Jomo Club Limited | Wholesale & retail | 2021 |
| JON Avol Properties Limited | Real estate | 2016 |
| JON Bignold Post Production Ltd | Information & communication | 2010 |
| JON Howes Remote Heads Limited | Other services | 2012 |
| JON Marlow (Residential) Limited | Real estate | 2024 |
| JON Marlow Limited | Real estate | 2018 |
| Jonasco Solutions Ltd | Administrative & support | 2015 |
| Jonathan Raymond Security Ltd. | Administrative & support | 2021 |
| Jonathan Tinnacher Consulting Ltd. | Education | 2016 |
| Jones Healthcare Limited | Health & social care | 2023 |
| Jones Property Consultancy Ltd | Real estate | 2024 |
| Jongeconstructions Ltd | Construction | 2021 |
| Jonny MP Photography Limited | Professional & scientific | 2014 |
| Jonny Mp.Co Limited | Professional & scientific | 2017 |
| Jonny.Tv Limited | Information & communication | 2011 |
| Joon LEE Limited | Health & social care | 2016 |
| Jooste Marketing Ltd | Professional & scientific | 2022 |
| Jora Services Ltd | Construction | 2010 |
| Jordan MAY Media Limited | Professional & scientific | 2022 |
| Jordan Verdes Ltd | Arts & recreation | 2025 |
| Joseph Anderson Beadle Ltd | Professional & scientific | 2025 |
| Joseph Contractors Ltd | Information & communication | 2016 |
| Josephinejoy Ltd | Professional & scientific | 2025 |
| Josh & Co Builders Ltd | Construction | 2026 |
| Josh Investments Corporation Ltd | Wholesale & retail | 2023 |
| Joshfx Ltd | Information & communication | 2023 |
| Joshi Home Care Ltd | Health & social care | 2022 |
| Joshi Partnership Limited | Real estate | 2018 |
| Joshi-Laa Solutions Limited | Information & communication | 2006 |
| Joshua Construct Ltd | Construction | 2016 |
| Joshua Oliver Concierge Ltd | Other services | 2016 |
| Joshua Oliver Real Estate Ltd | Real estate | 2024 |
| Jossour Trans Luggage Ltd | Transport & logistics | 2023 |
| Jostec Limited | Professional & scientific | 2011 |
| JOT Mobile FIX Limited | Other services | 2022 |
| Journey Technologies Ltd | Health & social care | 2025 |
| Joury Estates Limited | Real estate | 2024 |
| Joy and John Limited | Health & social care | 2023 |
| Joy in the Details Limited | Professional & scientific | 2025 |
| Joya and Sons Ltd | Wholesale & retail | 2020 |
| Joys Newsmart Limited | Wholesale & retail | 2010 |
| Joytide Studio Ltd | Wholesale & retail | 2019 |
| JP Accountancy and Taxation Solutions Ltd | Professional & scientific | 2010 |
| JP Capital Investments Ltd | Real estate | 2020 |
| JP Distributors International Ltd | Wholesale & retail | 2025 |
| JP Engineering Solutions Ltd | Manufacturing | 2025 |
| JP INV Ltd | Real estate | 2024 |
| JP IT Management Services Ltd | Information & communication | 2018 |
| JP M Enterprise Ltd | Wholesale & retail | 2026 |
| JP Madison Limited | Financial services | 2018 |
| JP Management and Construction Ltd | Construction | 2026 |
| JP Marketing Solutions Limited | Information & communication | 2022 |
| JP Nest UK Ltd | Real estate | 2026 |
| JP Pharma Solutions Limited | Professional & scientific | 2016 |
| JP Ralls Enterprises Limited | Financial services | 2024 |
| JP Sohi Properties Limited | Administrative & support | 2023 |
| JP Takeaway Ltd | Hospitality | 2024 |
| Jparmar Greenford Limited | Financial services | 2021 |
| Jpcv Ltd | Information & communication | 2014 |
| JPD Build and Design Limited | Construction | 2025 |
| JPD Property Investment Ltd | Real estate | 2020 |
| Jpexec Limited | Administrative & support | 2004 |
| JPJ Industries Ltd | Arts & recreation | 2021 |
| JPK Heatpumps Ltd | Professional & scientific | 2007 |
| JPM Homes Limited | Real estate | 2016 |
| Jpnc Ltd. | Professional & scientific | 2013 |
| Jpns Electrical Limited | Construction | 2026 |
| Jpps Properties Ltd | Professional & scientific | 2017 |
| JPR Brampton Properties Limited | Real estate | 2025 |
| JPR Invest Ltd | Real estate | 2021 |