| JAI J Whyte Ltd | Construction | 2018 |
| Jaidal Services SP | | 2004 |
| Jaifa Limited | Transport & logistics | 2023 |
| Jaishakuntla Limited | Hospitality | 2026 |
| JAK23 Ltd | Real estate | 2023 |
| Jake and AVA Trading Limited | Hospitality | 2024 |
| Jakhura Enterprises Ltd | Wholesale & retail | 2025 |
| JAL Scotland Limited | Financial services | 2013 |
| Jali Care Services Ltd | Administrative & support | 2024 |
| Jali Collective Ltd | Information & communication | 2026 |
| Jaloma LP | | 2001 |
| JAM Consultancy Ltd | Professional & scientific | 2021 |
| JAM Investment Management Ltd | Extraterritorial | 2012 |
| JAM Line Business LP | | 2016 |
| JAM Print Alliance Group Limited | Manufacturing | 2026 |
| Jamaica Edinburgh Limited | Real estate | 2020 |
| Jamaica Howe Ltd | Hospitality | 2024 |
| Jamaica Inter NET LP | | 2014 |
| Jamaica IP Limited | Real estate | 2020 |
| Jamaican Oy'Nissh Ltd | Hospitality | 2019 |
| Jamal's Restaurants Ltd | Hospitality | 2023 |
| Jamber Limited | Real estate | 2009 |
| James a Carlyle & SON Limited | Construction | 2020 |
| James Alexander Salesforce Agent Ltd | Administrative & support | 2026 |
| James Allan & Sons Scotland Ltd | Wholesale & retail | 2009 |
| James Blake & Co (Engineers) Limited | Manufacturing | 1961 |
| James Borthwick Ltd | Wholesale & retail | 2008 |
| James Bowen & Sons, Limited | Real estate | 1939 |
| James Breck (Holdings) Limited | Professional & scientific | 2017 |
| James Breck Limited | Construction | 1972 |
| James Campbell Tours Ltd | Administrative & support | 2023 |
| James Chute Limited | Professional & scientific | 2015 |
| James Durey Financial Planning Ltd | Professional & scientific | 2019 |
| James Erskine Interiors Limited | Professional & scientific | 2014 |
| James Erskine Limited | Wholesale & retail | 1984 |
| James Fleming & Company Limited | Manufacturing | 1991 |
| James Fraser & Co. (Edinburgh) Ltd | Professional & scientific | 2012 |
| James Gammell & SON Limited | Agriculture & fishing | 1964 |
| James Gillespie's Campus Subhub Holdings Limited | Financial services | 2013 |
| James Gillespie's Campus Subhub Limited | Construction | 2013 |
| James Grant & Company (West) Limited | Professional & scientific | 1933 |
| James J Gray Ltd | Other services | 2023 |
| James Laidlaw & Sons, Limited | | 1921 |
| James Maclachlan Ltd | Other services | 2024 |
| James Martin & Company, Limited | Manufacturing | 1912 |
| James Neil & SON Plumbing and Heating Limited | Construction | 2022 |
| James Paul & Partners Limited | Other services | 2016 |
| James Paul and Sons Limited | Other services | 2011 |
| James Penman (Plant Hire) Limited | Administrative & support | 1977 |
| James Potter (Builders) Limited | Construction | 1984 |
| James Potter Properties Limited | Construction | 1987 |
| James Ritchie & SON (Clockmakers) Limited | Manufacturing | 2001 |
| James Sandie & SON Ltd | Construction | 2024 |
| James Scott (Holdings) Ltd | Arts & recreation | 2018 |
| James Simpson's Properties (Edinburgh) Limited | Real estate | 1964 |
| James Spratt Consultancy Ltd. | Health & social care | 2011 |
| James Stewart Exhibitions Limited | Real estate | 1978 |
| James Strutt Site Services Limited | Construction | 2017 |
| James Wilson Interiors Limited | Wholesale & retail | 2006 |
| James Wyld Limited | Administrative & support | 2024 |
| James-Morrow Home Entertainment Systems Limited | Wholesale & retail | 2002 |
| James-Morrow LLP | | 2007 |
| James-Morrow Property Limited | Real estate | 2017 |
| Jameson Properties Limited | Real estate | 2021 |
| Jamie Andrew Limited | Administrative & support | 2014 |
| Jamie Dillon Plumbing & Heating Ltd | Construction | 2019 |
| Jamie Dillon Property Ltd | Real estate | 2026 |
| Jamie Genevieve Ltd | Other services | 2017 |
| Jamie Kelly Ltd | Transport & logistics | 2026 |
| Jamie Kirk PT Limited | Other services | 2024 |
| Jamieson Hearing Consultants Ltd | Wholesale & retail | 2025 |
| Jamieson Law Ltd | Professional & scientific | 2018 |
| Jamira LP | | 2016 |
| Jamjam Studios Limited | Professional & scientific | 2022 |
| Jamjar 3 Carried Interest GP LLP | | 2026 |
| Jamjar Carried Interest GP LLP | | 2021 |
| Jamjar Ventures 3 Carry LP | | 2026 |
| Jamjar Ventures II Carry LP | | 2021 |
| Jamkar Travel Ltd | Real estate | 2025 |
| Jamma Umoja (Residential Services) Limited | Health & social care | 2003 |
| JAN Building Contractor Ltd | Construction | 2013 |
| Janacek Limited Partnership | | 2006 |
| Janack Limited | Professional & scientific | 2008 |
| Janackerman Services | | 2004 |
| Jancoast Trading LP | | 2014 |
| Jandrmelts Ltd | Wholesale & retail | 2025 |
| Jane Paul Recruitment Limited | Administrative & support | 2007 |
| Jane Perfect Interiors Limited | Professional & scientific | 2019 |
| Jane Street Properties Limited | Real estate | 2020 |
| Janeira LP | | 2015 |
| Janeiro Empire LP | | 2015 |
| Janeiro Wings LP | | 2015 |
| Janesta Elegant LP | | 2015 |
| Janet Jeanes Ltd | Extraterritorial | 2012 |
| Janford Estate LP | | 2013 |
| Janica Ltd | Information & communication | 2013 |
| Janice Homes Ltd | Real estate | 2023 |
| Janine LU Enterprises Limited | Information & communication | 2023 |
| Jankee Beauty Ltd | Wholesale & retail | 2024 |
| Janki Group Ltd | Manufacturing | 2023 |