| IP Umbrella Ltd | Professional & scientific | 2025 |
| Ironforse Limited | Transport & logistics | 2015 |
| Island Aviation Limited | Extraterritorial | 2000 |
| Island Community Hub CIC | Education | 2025 |
| Island Cruises Ltd | Transport & logistics | 2017 |
| Island Ductwork Limited | Manufacturing | 2010 |
| Island Fish Bar Ltd | Hospitality | 2018 |
| Island Highland Limited | Agriculture & fishing | 2025 |
| Island Leisure Holiday Parks Limited | Hospitality | 2020 |
| Island Plastics (Kent) Limited | Wholesale & retail | 2012 |
| Island Produce Retail Limited | Wholesale & retail | 2022 |
| Island Property Investments Ltd | Real estate | 2023 |
| Island Scaffolding Limited | Construction | 1986 |
| Island Services Limited | Manufacturing | 1997 |
| Island Training Services Limited | Professional & scientific | 2013 |
| Island Windows Kent Limited | Manufacturing | 2014 |
| Isle Supply Ltd | Wholesale & retail | 2018 |
| It’S the Source Limited | Hospitality | 2022 |
| J & D Commercials Ltd | Wholesale & retail | 2025 |
| J F Attwood (Estates) Limited | Real estate | 2020 |
| J F Attwood Estates (Residential) Limited | Real estate | 2024 |
| J Robinson Services Ltd | Construction | 2017 |
| J Shurvell Electrics Ltd | Construction | 2019 |
| J3CASHEW Ltd | Health & social care | 2021 |
| Jack Bater Limited | Transport & logistics | 2025 |
| Jacobus Solutions Limited | Professional & scientific | 2024 |
| Jahaziel Ltd | Health & social care | 2022 |
| James Park Estates Ltd | Financial services | 2019 |
| James Parks Developments Limited | Construction | 2021 |
| James Perry & Partners ( Sevenoaks) Ltd | Real estate | 2021 |
| James Perry & Partners Limited | Real estate | 2019 |
| JAT PX Quality Inspections Limited | Construction | 2020 |
| Jaydek Limited | Wholesale & retail | 2024 |
| Jaymc Interiors Limited | Construction | 2019 |
| JBE Contractors Limited | Construction | 2023 |
| JBF Digital Limited | Manufacturing | 2017 |
| JD Staff Ltd | Administrative & support | 2018 |
| JDA (Kent) Limited | Administrative & support | 2011 |
| Jdautomotivesuk Ltd | Wholesale & retail | 2019 |
| Jeffrey Property Group Ltd | Real estate | 2026 |
| Jefson Ltd | Health & social care | 2023 |
| Jejw Properties Ltd | Real estate | 2022 |
| JEM Electrical Services Ltd | Construction | 2022 |
| Jenwood Printers Limited | Manufacturing | 1971 |
| Jess Lovibond Therapeutic Services CIC | Health & social care | 2021 |
| Jett-Tech Solutions Ltd | Information & communication | 2024 |
| JGP Electrical Ltd | Construction | 2023 |
| Jiyarth International Limited | Information & communication | 2024 |
| JJB Properties (Kent) Ltd | Real estate | 2016 |
| JJB Property Services Ltd | Construction | 2015 |
| JJL Moon Properties Ltd | Households | 2021 |
| Jj’S Invest Ltd | Real estate | 2024 |
| JLINDUSTRIES1 Limited | Transport & logistics | 2025 |
| JNC Investments Ltd | Real estate | 2018 |
| John Charles Scopes Ltd | Construction | 2022 |
| John Hangan Ltd | Administrative & support | 2025 |
| Joinery for ALL Seasons Ltd | Construction | 2014 |
| Joymax Ltd | Other services | 2014 |
| JPB Builders Limited | Construction | 2024 |
| JPD Contractors Ltd. | Construction | 2016 |
| JPR Scaffolding Ltd | Construction | 2026 |
| JR Advanced Welding Services Limited | Professional & scientific | 2025 |
| JS Welding&Fabrication Ltd | Other services | 2022 |
| JSF Consulting & Buying Ltd | Administrative & support | 2021 |
| JSM Passive Fire Protection Ltd | Public administration | 2021 |
| Jsnt Holdings Limited | Real estate | 2021 |
| JT Cooling Ltd | Other services | 2025 |
| JU Drilling Limited | Construction | 2025 |
| JU Mobile Mechanics Ltd | Professional & scientific | 2026 |
| Jubilee Dent Ltd | Administrative & support | 2022 |
| Just Genie Ltd | Administrative & support | 2024 |
| Justancorr Ltd | Real estate | 2018 |
| Justdean Ltd | Extraterritorial | 2015 |
| JVB Electrical Solutions Limited | Construction | 2015 |
| JWG Engineering Ltd | Other services | 2023 |
| JWL Haulage Ltd | Transport & logistics | 2022 |
| JWT Investments Ltd | Financial services | 2025 |
| K H Steel Services Limited | Construction | 2020 |
| K O'Brien Ltd | Professional & scientific | 2025 |
| K Riches Security Services Ltd | Administrative & support | 2026 |
| K&M Building & Construction Limited | Construction | 2018 |
| K&T Healthcare Ltd | Professional & scientific | 2023 |
| K.A.P.S. Building Services Limited | Construction | 2002 |
| K.N.J. Electrical Services Ltd | Construction | 2010 |
| Kanaka Ltd | Professional & scientific | 2017 |
| Kanzon Ltd | Professional & scientific | 2024 |
| Karian Property Developments Ltd | Construction | 2018 |
| Kay's Kitchen (Kent) Ltd | Hospitality | 2023 |
| KBP Aesthetics Health and Beauty Clinic Ltd | Other services | 2025 |
| Kc's Demons Ltd | Households | 2020 |
| Kealtec UK Limited | Manufacturing | 2025 |
| Kelly Electrical Services Ltd | Construction | 2018 |
| Kenandtay Properties Ltd | Real estate | 2026 |
| Kendall Dentures Ltd | Health & social care | 2018 |
| Kendo Ltd | Administrative & support | 2005 |
| Kent Barbers 3 Limited | Other services | 2016 |
| Kent Bath Repair and RE Enamelling Limited | Other services | 2026 |
| Kent Bookkeeping Limited | Professional & scientific | 2018 |
| Kent Carriage Masters Ltd | Administrative & support | 2023 |
| Kent Catering Engineers Ltd | Manufacturing | 2021 |