| Jitevami Ltd | Hospitality | 2023 |
| JJ & LL Group Limited | Construction | 2025 |
| JJ Co Investments Ltd | Real estate | 2023 |
| JJ Cooper Holdings Ltd | Information & communication | 2025 |
| Jja's Products Ltd | Wholesale & retail | 2023 |
| Jjah Consultants Ltd | Professional & scientific | 2020 |
| Jjan 19 Limited | Professional & scientific | 2024 |
| Jjan Properties Limited | Real estate | 2024 |
| JJE Capital Ltd | Professional & scientific | 2013 |
| JJH Surveyors Ltd | Professional & scientific | 2011 |
| JJJ Accounting and Financial Services Ltd | Professional & scientific | 2026 |
| JJS CIM Limited | Information & communication | 2016 |
| JJW Financial Planning Limited | Financial services | 2013 |
| Jjwh Investment Ltd | Real estate | 2026 |
| JK Chiropractic Limited | Health & social care | 2022 |
| JK Dragon Property Limited | Real estate | 2026 |
| JK Equestrian LLP | | 2019 |
| Jkarvelis Ltd | Manufacturing | 2023 |
| JKB Convenience Store Ltd | Wholesale & retail | 2017 |
| JKB Retail Store Ltd | Wholesale & retail | 2016 |
| JKB Solutions Ltd | Transport & logistics | 2025 |
| JKB Stores Ltd | Wholesale & retail | 2022 |
| JKL Dairy & Food Services Limited | Wholesale & retail | 2018 |
| JKL Fleet Services Ltd | Wholesale & retail | 2026 |
| Jklinventory Services Ltd | Real estate | 2015 |
| JKM Home Inspections Ltd | Professional & scientific | 2019 |
| Jkmk Developments Ltd | Construction | 2024 |
| JKS Formula Cars Limited | Professional & scientific | 1994 |
| JL Auto Limited | Wholesale & retail | 2025 |
| JL Creative Ltd | Professional & scientific | 2019 |
| JL Developments Harpenden Limited | Construction | 2019 |
| JL Projects Limited | Construction | 2024 |
| JL Propertites Limited | Real estate | 2024 |
| JL Real Estate Ltd | Real estate | 2026 |
| JLA Houses Limited | Real estate | 2022 |
| JLB Property Maintenance Ltd | Construction | 2013 |
| JLB Pumps Ltd | Manufacturing | 2026 |
| JLB Retail Ltd | Wholesale & retail | 2019 |
| JLC Design Solutions Ltd | Professional & scientific | 2017 |
| JLC HR Consultancy Ltd | Professional & scientific | 2022 |
| JLD Surfacing Limited | Construction | 2023 |
| JLE Group Holdings Limited | Financial services | 2026 |
| JLE Heating and Plumbing Ltd | Construction | 2021 |
| JLN1 Ltd | Hospitality | 2016 |
| JLO Transport Ltd | Transport & logistics | 2018 |
| JLP Software Ltd | Information & communication | 2014 |
| Jlsa Solutions Limited | Manufacturing | 2020 |
| JM Driver Services Ltd | Transport & logistics | 2025 |
| JM Fundraising Ltd | Other services | 2024 |
| JM Principle Ltd | Professional & scientific | 2016 |
| JM Residentials Ltd | Real estate | 2019 |
| JM& Co Services Ltd | Transport & logistics | 2018 |
| JM2 Properties Ltd | Real estate | 2025 |
| Jmac Supps Ltd | Health & social care | 2025 |
| JMB Construction Solutions Ltd | Construction | 2010 |
| JMC Care Solutions Limited | Administrative & support | 2014 |
| JMC Flooring Ltd | Wholesale & retail | 2019 |
| JMC Hairs Ltd | Wholesale & retail | 2025 |
| Jmcatering Solutions Ltd | Hospitality | 2022 |
| JMD and SON Limited | Real estate | 2023 |
| JMG Realisations Ltd | Financial services | 2006 |
| JMG Transport Northampton Limited | Transport & logistics | 2016 |
| Jmkm Ltd | Transport & logistics | 2013 |
| JMM Construction Solutions Ltd. | Construction | 2016 |
| JMM Repair Ltd | Wholesale & retail | 2025 |
| JMM Technology Limited | Information & communication | 2025 |
| JMR Land & Buildings Limited | Real estate | 2015 |
| JMR Property (Midlands) Limited | Construction | 2014 |
| Jmrcomms Limited | Information & communication | 2020 |
| JMT Supplies Ltd | Wholesale & retail | 2023 |
| JMZ Ltd | Wholesale & retail | 2021 |
| JNB Portfolio Research & Consulting Ltd | Professional & scientific | 2025 |
| Jnbjanebu Limited | Wholesale & retail | 2025 |
| JNJ Convenience Ltd | Wholesale & retail | 2021 |
| Jnmdistros Ltd | Wholesale & retail | 2025 |
| Jnrr Consultancy Ltd | Professional & scientific | 2022 |
| JO Chauffeurs Ltd | Transport & logistics | 2019 |
| JO Jingles Franchise UK Ltd | Education | 2025 |
| JO Pereira Ltd | Professional & scientific | 2018 |
| JO Spencer (Consulting) Limited | Professional & scientific | 2018 |
| JO Ward Psychology Limited | Health & social care | 2023 |
| Jo-Pa Property Services Ltd | Households | 2021 |
| Joana Trans Ltd | Transport & logistics | 2026 |
| JOB Done Electrical Services Limited | Construction | 2014 |
| JOB Trans 4 U UK Ltd | Wholesale & retail | 2022 |
| Jobbar Ltd | Administrative & support | 2023 |
| Jobflow Systems Ltd | Information & communication | 2026 |
| Jobrefer Ltd | Information & communication | 2021 |
| Jobs-R-Us Recruitment Ltd | Administrative & support | 2022 |
| JOC Plastering & Rendering Limited | Construction | 2025 |
| Jocapt Cleaning Services Ltd | Administrative & support | 2024 |
| Jodi Ellen Malpas Limited | Arts & recreation | 2012 |
| Jodi Ellen Malpas Literature Limited | Information & communication | 2014 |
| Jodrell Site Services Ltd | Other services | 2024 |
| JOE Cruise Limited | Construction | 2018 |
| JOE Harber Plumbing & Heating Ltd | Construction | 2026 |
| JOE Jeffery Limited | Education | 2013 |
| JOE Sacarello's Specialty Coffees Ltd. | Wholesale & retail | 2015 |
| Joel. a. Beardsmore Limited | Real estate | 2021 |
| Jofitness Ltd | Arts & recreation | 2025 |