| Intellicorelogistics Ltd | Administrative & support | 2026 |
| Intercity Plumbing Merchants Ltd | Wholesale & retail | 2016 |
| International Legal Assistance LP | | 2014 |
| Inverdawn Limited | Construction | 2003 |
| Inverewe Properties Ltd | Households | 2025 |
| Iport Energy Ltd | Information & communication | 2012 |
| Ires-Geo Technology (UK) Limited | Mining & quarrying | 2016 |
| Irfania Limited | Health & social care | 2012 |
| Iroko Carpentry Ltd | Construction | 2010 |
| Irongate Technology Ltd | Information & communication | 2026 |
| Ironstone Films Ltd | Information & communication | 2018 |
| Irsh Ltd | Wholesale & retail | 2026 |
| Irvine Stewart Talent Partners Ltd | Administrative & support | 2026 |
| Ised Ltd | Real estate | 2018 |
| Ishafi Limited | Real estate | 2026 |
| Island Drip Ltd | Wholesale & retail | 2026 |
| IT Sameday Ltd | Information & communication | 2012 |
| Itylfe Ltd | Information & communication | 2013 |
| Ivaan Ltd | Information & communication | 2024 |
| Ivalo Recruitment & Consulting Ltd | Administrative & support | 2016 |
| Izyrent Ltd | Real estate | 2024 |
| J & R Stewart Ltd | Other services | 2025 |
| J K Dumble Ltd | Information & communication | 2017 |
| J Peters Logistics Ltd | Transport & logistics | 2020 |
| J Wallace & Sons Ltd | Real estate | 2020 |
| J Wallace Business Consulting Ltd | Professional & scientific | 2017 |
| J&D's Properties Ltd | Real estate | 2024 |
| J. Hewit & Sons Limited | Manufacturing | 1931 |
| J.L Joiner Ltd | Construction | 2022 |
| Jabil Partners | | 1997 |
| Jackandco Limited | Real estate | 2019 |
| Jackie Dickson Ltd | Information & communication | 2017 |
| Jacobs Place Limited | Hospitality | 2019 |
| Jaei Commercial Services Limited | Professional & scientific | 2024 |
| Jageroth Ltd | Financial services | 2025 |
| Jakobbrothers Ltd | Construction | 2024 |
| JAL Inspection Ltd | Construction | 2023 |
| Jals Property Ltd | Real estate | 2021 |
| Jamara Taxis Ltd. | Transport & logistics | 2004 |
| James Dick (Farming) Limited | Agriculture & fishing | 1958 |
| James Lindsay & SON Public Limited Company | Extraterritorial | 1898 |
| James Walker (Leith) Limited | Manufacturing | 1949 |
| Jaslin Construction Limited | Construction | 2011 |
| JAY Hogarty Properties Ltd | Real estate | 2020 |
| Jaymo&Co Ltd | Agriculture & fishing | 2026 |
| JBA2025 Ltd | Hospitality | 2024 |
| JBB Contracting Ltd. | Administrative & support | 2010 |
| JC Heating & GAS Services Ltd | Other services | 2021 |
| JC Renewable Energy Ltd | Construction | 2026 |
| JCM Haulage Ltd | Transport & logistics | 2026 |
| JCR Partnership LLP | | 2020 |
| Jcsec Ltd | Construction | 2024 |
| Jdmc Scientific Consultancy Limited | Professional & scientific | 2020 |
| JDS Facilities Ltd | Construction | 2018 |
| Jedox Couriers Ltd | Wholesale & retail | 2022 |
| Jedox Group Limited | Wholesale & retail | 2021 |
| Jeff Hutchison Mortgage & Protection Ltd | Financial services | 2020 |
| Jessica Anderton Designs Limited | Manufacturing | 2025 |
| Jets Activity Club Community Interest Company | Arts & recreation | 2019 |
| JFC Partners Ltd | Hospitality | 2026 |
| JFJ Seated Moves Ltd | Other services | 2025 |
| JG Geosolutions Ltd | Professional & scientific | 2021 |
| JGM Law Accountants Ltd | Professional & scientific | 2021 |
| Jharecribs Limited | Administrative & support | 2025 |
| Jigsaw Studio Ltd | Information & communication | 2026 |
| JJ Practice Ltd | Health & social care | 2015 |
| Jjom Services Limited | Hospitality | 2023 |
| Jkdirect Ltd | Real estate | 2024 |
| JL Turbert Services Ltd | Information & communication | 2026 |
| JM Quantum Ltd | Professional & scientific | 2025 |
| JMJ Propertycare Ltd | Construction | 2025 |
| JMT Care Services Limited | Health & social care | 2009 |
| John Heaney (Electrical) Limited | Construction | 1990 |
| John R. Colbron Taxis Ltd. | Transport & logistics | 2000 |
| John Watson Architectural Consultant Limited | Professional & scientific | 2004 |
| Johnny Green Training Limited | Information & communication | 2025 |
| Joseph Mccafferty Developments Limited | Construction | 2017 |
| JR Motors Autocare Ltd | Wholesale & retail | 2023 |
| JR Motors Livingston Ltd | Wholesale & retail | 2025 |
| JRS Tree Services Ltd | Agriculture & fishing | 2023 |
| JS DS Enterprise Limited | Wholesale & retail | 2023 |
| JSP Innovative Solutions Ltd | Information & communication | 2019 |
| Jsretail DDD Ltd | Professional & scientific | 2022 |
| Jsriman Ltd | Transport & logistics | 2026 |
| Julia Jaworska Ltd | Health & social care | 2025 |
| Julian Logistics Ltd | Transport & logistics | 2026 |
| Juliet Ruth Properties Ltd | Real estate | 2023 |
| Junior Mind International Academy UK Ltd | Education | 2025 |
| Juniva Homecare Services Ltd | Health & social care | 2022 |
| JWC Washroom Services Ltd | Construction | 2026 |
| Jyle Ltd | Wholesale & retail | 2024 |
| K Label Group Limited | Manufacturing | 2020 |
| K. Properties(Gb) Ltd | Households | 2025 |
| K.N91 Ltd | Transport & logistics | 2025 |
| K4 Electrical Ltd | Construction | 2025 |
| Kadir Consultants Ltd | Information & communication | 2024 |
| Kakekaizen Ltd | Professional & scientific | 2026 |
| Kal-Med Consulting C.I.C. | Wholesale & retail | 2018 |
| Kanbaro Ltd | Information & communication | 2016 |
| Kapta Investments | | 2007 |