| I Andrews Limited | Real estate | 2021 |
| I Hub Trading Limited | Wholesale & retail | 2023 |
| Ibroo Ltd | Administrative & support | 2009 |
| Identity R & D Ltd | Information & communication | 2018 |
| Ihub Mobiles Ltd | Wholesale & retail | 2024 |
| IMC Installations Limited | Construction | 2010 |
| Imedia Creative Technologies Ltd | Information & communication | 2012 |
| Imogen Prosser Limited | Professional & scientific | 2026 |
| Impex Trade (UK) Limited | Wholesale & retail | 2016 |
| Implied Technology Solutions Ltd | Information & communication | 2022 |
| IN Depth Audio Productions Ltd | Information & communication | 2025 |
| IN Rhodes Limited | Other services | 2022 |
| IN the Detail Squared Ltd. | Information & communication | 2026 |
| Independent HR Ltd | Administrative & support | 2015 |
| Industrial Coatings Western Limited | Professional & scientific | 2002 |
| Ingenotrac Technologies Limited | Professional & scientific | 2024 |
| Ingerlite Electrical & Property Services Limited | Construction | 2019 |
| Innerrace Performance Ltd | Information & communication | 2026 |
| Innovation Bath Limited | Professional & scientific | 2011 |
| Innpressive Bars Limited | Hospitality | 2016 |
| Inspire Care Housing Limited | Real estate | 2025 |
| Inspire Children Services Ltd | Public administration | 2023 |
| Inspire Together Ltd | Administrative & support | 2021 |
| Internet Marketing Group Limited | Information & communication | 2019 |
| Intex Building Company Ltd | Construction | 2024 |
| Intoheat Infrastructure Management Limited | Construction | 2026 |
| Inventory Partner Ltd | Real estate | 2026 |
| Invertech Drainage Solutions Ltd | Water & waste | 2022 |
| IOS Studios Ltd | Arts & recreation | 2024 |
| Irrp Vehicle Solutions Ltd | Wholesale & retail | 2025 |
| Isati Limited | Administrative & support | 2019 |
| Island Cottage Old Church Road Flat Management Company Limited | Households | 1982 |
| IWANT2KNOW Ltd | Education | 2023 |
| J + A.W. Sully (Clevedon) Limited | Professional & scientific | 1999 |
| J M G Property Management Limited | Real estate | 2020 |
| J&B Property Services Limited | Real estate | 2025 |
| J. Edward Sellars (Nominees) Limited | Financial services | 1985 |
| J. Edward Sellars and Partners Limited | Financial services | 1975 |
| J20M Ltd | Wholesale & retail | 2018 |
| Jack (Air) International Limited | Extraterritorial | 1993 |
| Jacklands Fishing Lakes LLP | | 2009 |
| JAD Engineering Services Limited | Construction | 2010 |
| JAK Roome Creative Ltd | Other services | 2025 |
| JAM Events & Production Ltd | Arts & recreation | 2014 |
| James Ryan Law Limited | Professional & scientific | 2025 |
| Jammy Property Limited | Real estate | 2025 |
| JAN Oliff Financial Planning Limited | Financial services | 2015 |
| Jarvis GAS and Heating Ltd | Construction | 2021 |
| Jarvvos Ltd | Wholesale & retail | 2023 |
| Jaycekay Limited | Transport & logistics | 2025 |
| Jayneil Shokai Ltd | Wholesale & retail | 2020 |
| JCW Civils&Groundworks Limited | Construction | 2025 |
| Jennys Cafe Shop Ltd | Wholesale & retail | 2023 |
| Jeremy Lawrence Property Limited | Real estate | 2018 |
| Jess Pompey DCP Agency Limited | Health & social care | 2012 |
| Jessica Barker Property Services Limited | Real estate | 2025 |
| Jessica Varnish Management Ltd | Health & social care | 2010 |
| Jetbrick Limited | Construction | 2004 |
| JGL Ball Property Ltd | Real estate | 2026 |
| JH Winter Limited | Professional & scientific | 2011 |
| JJ Prestige Ltd | Wholesale & retail | 2025 |
| JMR Planning Law Limited | Professional & scientific | 2017 |
| JMS Refrigeration Services Ltd | Manufacturing | 2015 |
| JMW Ecology Ltd | Professional & scientific | 2023 |
| JNH Renovations Ltd | Construction | 2022 |
| Joanne’S Driving School Ltd | Education | 2026 |
| JOE Williams Plumbing and Heating Ltd | Construction | 2022 |
| Jonathan Hedges Limited | Transport & logistics | 2014 |
| Jones Ponsford Hospitality Ltd | Hospitality | 2026 |
| Jordan Dale Holdings Ltd | Financial services | 2020 |
| Joseph Connor JCD Ltd | Information & communication | 2025 |
| Josh Stanton-Humphreys Ltd | Hospitality | 2025 |
| Joshua Hovey Architects Ltd | Professional & scientific | 2020 |
| JP Healthcare Assessments Ltd | Health & social care | 2025 |
| JRW Haulage Limited | Wholesale & retail | 1995 |
| JS Plastering Ltd | Construction | 2014 |
| Jubilee Court Wick Road Limited | Households | 2002 |
| Jules Baque Engineering Ltd | Professional & scientific | 2025 |
| Jumping Jack Marketing Limited | Professional & scientific | 1998 |
| Just Request Welding Supplies Ltd | Other services | 2026 |
| JW Barbers Limited | Other services | 2015 |
| JWI Commercial Ltd | Professional & scientific | 2026 |
| JZB Words Limited | Professional & scientific | 2020 |
| K Consulting (Portishead) Limited | Professional & scientific | 2017 |
| Kalisto Group Ltd | Construction | 2025 |
| Kane Business Consulting Limited | Professional & scientific | 1999 |
| Kaocommerce Ltd | Wholesale & retail | 2024 |
| Karp Construction Ltd | Construction | 2014 |
| Katie's Green Gardening Ltd | Administrative & support | 2024 |
| Katie's Hair Studio Ltd | Other services | 2022 |
| Kavanagh Ward Limited | Financial services | 2019 |
| Kelvins Butchers Limited | Wholesale & retail | 2016 |
| Kenn Knights Limited | Real estate | 2016 |
| Kensho Leadership Limited | Professional & scientific | 2025 |
| KFM Property Services Ltd | Real estate | 2024 |
| KHG Leadership Consulting Limited | Professional & scientific | 2026 |
| Kindfolk Digital Ltd | Information & communication | 2025 |
| Kinetic Health Holdings Ltd | Health & social care | 2020 |
| Kings Road Clevedon (Management) Limited | Households | 2002 |
| Kirsty's Kleaners Limited | Administrative & support | 2017 |