| JH Family Office Ltd | Financial services | 2013 |
| Jhannah Consulting Limited | Wholesale & retail | 2018 |
| Jhd.Design Ltd | Manufacturing | 2023 |
| JHH Holdings Ltd | Financial services | 2024 |
| Jiamax Transport Limited | Transport & logistics | 2025 |
| Jilade Consulting Ltd | Professional & scientific | 2014 |
| JIW Limited | Professional & scientific | 2012 |
| Jiya T Ltd | Health & social care | 2025 |
| JJ Media & Socials Ltd | Information & communication | 2026 |
| JJ Tranz Ltd | Transport & logistics | 2020 |
| JJ Ultrasound Ltd | Health & social care | 2024 |
| JJC Enterprises Ltd | Professional & scientific | 2009 |
| Jjcs Properties Ltd | Real estate | 2021 |
| JJM and Sons Ltd | Real estate | 2025 |
| JJP Rainbow Foundation | Professional & scientific | 2015 |
| Jjst Developments Limited | Construction | 2019 |
| JJW Edgeineering Ltd | Construction | 2014 |
| JJY Logistics Ltd | Transport & logistics | 2025 |
| JK & SK Limited | Real estate | 2014 |
| JK Boundaries Ltd | Manufacturing | 2024 |
| JK Builders (Ossett) Ltd | Construction | 2016 |
| JK Festivals Ltd | Hospitality | 2025 |
| JK the Beauty POD Ltd | Other services | 2026 |
| JK Vehicle Body Repair Limited | Wholesale & retail | 2025 |
| JKD Cars Ltd | Wholesale & retail | 2015 |
| JKD3 Limited | Professional & scientific | 2015 |
| JKY Propertys Ltd | Real estate | 2025 |
| JL Services Leasehold Limited | Construction | 2008 |
| JLA Exterior Maintenance Ltd | Administrative & support | 2025 |
| JLB & LSB Accounting Ltd | Professional & scientific | 2025 |
| JLC PUB Management Ltd | Hospitality | 2022 |
| JLH Plumbing and Heating Ltd | Construction | 2013 |
| JLL Construction NW Ltd | Construction | 2025 |
| JLO Yorkshire Transport Ltd | Transport & logistics | 2025 |
| JLS Care Services Limited | Professional & scientific | 2026 |
| JLV Holdings Ltd | Real estate | 2025 |
| JM Brook Ltd | Other services | 2011 |
| JM Memorials Ltd | Other services | 2021 |
| JM Motor Group Ltd | Wholesale & retail | 2025 |
| JM Scott Properties Limited | Real estate | 2021 |
| JMB Medical Care Ltd | Health & social care | 2021 |
| Jmb-Radiology Limited | Health & social care | 2024 |
| Jmjetwise Ltd | Water & waste | 2021 |
| JMM Services Yorkshire Ltd | Construction | 2026 |
| JMP Music Limited | Information & communication | 2014 |
| JMP Property Estates Limited | Real estate | 2019 |
| JMR Freight Solutions Ltd | Transport & logistics | 2023 |
| JMT Shopfitters Ltd | Construction | 2009 |
| JMV Empire Ltd | Information & communication | 2024 |
| JN Grange Farm Limited | Agriculture & fishing | 2018 |
| JNB Civils Ltd | Construction | 2023 |
| Jnit Limited | Construction | 2025 |
| JNS Corporation Limited | Financial services | 2025 |
| JNS Hold Co Limited | Financial services | 2025 |
| JNV Quantity Surveyor Services Limited | Construction | 2004 |
| Joan's Sandwich Limited | Hospitality | 2023 |
| Joanna Maloney Limited | Professional & scientific | 2017 |
| Joanna Nowicka Transport Ltd | Transport & logistics | 2018 |
| JOB Earnshaw & Bros.Limited | Agriculture & fishing | 1911 |
| Jobaction Ltd | Administrative & support | 2025 |
| Jobson Jones Property Limited | Real estate | 2018 |
| Jocom Services Ltd | Wholesale & retail | 2016 |
| Jodathy Limited | Real estate | 2020 |
| JOE Hinchliffe T/A Reach to Clean Window Cleaning Ltd | Administrative & support | 2022 |
| JOE Lindley Ltd | Arts & recreation | 2020 |
| JOE Penny Media Ltd | Professional & scientific | 2024 |
| JOE Ralphs Coaching Ltd | Arts & recreation | 2022 |
| JOE Ralphs Limited | Arts & recreation | 2019 |
| Joeys Speed Shop Ltd | Wholesale & retail | 2021 |
| Joeys Speed Shop Parts Ltd | Wholesale & retail | 2024 |
| John Baker & Sons (Furnishers) Limited | Construction | 1948 |
| John Baxter Heating and GAS Services Ltd | Construction | 2026 |
| John Clifton Photography Limited | Professional & scientific | 2017 |
| John Cotter Services Ltd | Professional & scientific | 2022 |
| John Crowther Electricals Limited | Construction | 2019 |
| John Dobson & SON (Carlton) Limited | Agriculture & fishing | 1952 |
| John Dudding (2011) Ltd | Wholesale & retail | 2011 |
| John Dudding Limited | Wholesale & retail | 1969 |
| John H Carter Ltd | Administrative & support | 2009 |
| John Irvine Delivery Ltd | Transport & logistics | 2026 |
| John Layton Joinery Ltd | Construction | 2016 |
| John Marshall Consulting Ltd | Information & communication | 2012 |
| John Mitchell Enterprises Limited | Education | 2018 |
| John Philbin Limited | Extraterritorial | 2025 |
| John R Paley Associates Limited | Professional & scientific | 2001 |
| John Rannoch Limited | Manufacturing | 1933 |
| John Rhodes & SON (Ironfounders) Limited | Wholesale & retail | 2001 |
| John Shaw & Sons (Salford) Limited | Extraterritorial | 2004 |
| John Sparks Holdings Limited | Professional & scientific | 2016 |
| Johnson Rentals Ltd | Real estate | 2018 |
| Johnsons Green Consult Ltd | Professional & scientific | 2022 |
| Join the Momentum CIC | Education | 2024 |
| Joinery BR Ltd | Construction | 2025 |
| Joinery Direct Limited | Construction | 2008 |
| Jolly Boys PUB Company Ltd | Hospitality | 2019 |
| JON Gilbert (Property) Limited | Real estate | 2016 |
| JON Taylor EDT Ltd | Professional & scientific | 2022 |
| Jonam Limited | Construction | 2025 |
| Jonathan Ketteridge Associates Limited | Professional & scientific | 2005 |
| Jons Sheds Direct Limited | Manufacturing | 2015 |