| Holmes and Harris Property Limited | Real estate | 2019 |
| Home Neat Home Laundry Limited | Other services | 2023 |
| Homeneathome Ltd | Administrative & support | 2022 |
| Homestead (Southwold) Management Company Limited | Households | 2013 |
| Hook Mercor Ltd | Wholesale & retail | 2021 |
| Horse and Groom (Wrentham) Limited | Hospitality | 2020 |
| Hot's PPG Limited | Real estate | 2020 |
| Houlton and Moore Limited | Construction | 2024 |
| Howsham Memorials East Limited | Other services | 2024 |
| Howsham Memorials Limited | Other services | 2022 |
| Hughes Business Solutions Ltd | Information & communication | 2022 |
| Hughes Electrical Limited | Wholesale & retail | 1946 |
| Hughes Pension Trustee Limited | Professional & scientific | 2018 |
| Hughes Rental Limited | Administrative & support | 2020 |
| Hughes TV and Audio Limited | Wholesale & retail | 1961 |
| Hulver Waste Limited | Water & waste | 2010 |
| Hummingbird Hair Limited | Other services | 2025 |
| Huncoat Limited | Real estate | 2001 |
| Hungate Ltd | Hospitality | 2020 |
| Hypopressives With Alice Limited | Arts & recreation | 2024 |
| I Watson & Co Ltd | Professional & scientific | 2014 |
| IAN Smith Legal Services Ltd | Professional & scientific | 2011 |
| Ice Imports Ltd | Wholesale & retail | 2023 |
| IJB Services Ltd | Mining & quarrying | 2012 |
| Imscan Document Services Limited | Information & communication | 1992 |
| IN Addition Education Ltd | Education | 2020 |
| Include Counselling and Psychotherapy Services Ltd | Health & social care | 2025 |
| Indi's Wholesale Co. Ltd | Wholesale & retail | 2026 |
| Indianu Render Wall Insulation Ltd | Construction | 2020 |
| Indi’S Events Co. Ltd | Hospitality | 2026 |
| Infiniti Business Services Ltd | Administrative & support | 2025 |
| Ingate Builders Limited | Construction | 2018 |
| Ingate House Developments Ltd | Construction | 1988 |
| Ingatefreehouse Ltd | Other services | 2016 |
| Inspire Business Community Ltd | Administrative & support | 2025 |
| INT8GRATOR Limited | Information & communication | 2018 |
| INTEGR1TY Ltd. | Professional & scientific | 2020 |
| Interventions Business Ltd | Other services | 2017 |
| INVIGOR8TION Limited | Other services | 2010 |
| Iris & ORE Ltd | Manufacturing | 2023 |
| Istanbul Barbers Beccles Ltd | Other services | 2025 |
| Istanbul Hair Limited | Other services | 2019 |
| J Gowing Services Ltd | Professional & scientific | 2019 |
| J Plant Construction Limited | Construction | 2016 |
| J. & C. Stimpson Limited | Wholesale & retail | 2002 |
| Jaguar Properties 1 Limited | Real estate | 2022 |
| James Armstrong and Company Limited | Extraterritorial | 2012 |
| James Armstrong Holdings Limited | Extraterritorial | 2011 |
| James Burton Solutions Ltd | Professional & scientific | 2018 |
| James Miller Electrical Ltd | Construction | 2019 |
| Jarad Construction Ltd | Construction | 2017 |
| Jay's Hill Farming Limited | Agriculture & fishing | 2017 |
| Jaya Jwls Ltd | Wholesale & retail | 2024 |
| Jaye Builders Ltd | Other services | 2017 |
| Jaymat Ltd | Information & communication | 2025 |
| Jellyfish Media Ltd | Arts & recreation | 2007 |
| JEM Electrical Contractors Limited | Construction | 2013 |
| Jetbase Limited | Wholesale & retail | 2002 |
| JGM Leisure Limited | Hospitality | 2017 |
| JIM Shelley Carp Fishing Limited | Agriculture & fishing | 2017 |
| JIM Shelley Unleashed Ltd | Information & communication | 2024 |
| Joanne & Colin Smith Limited | Hospitality | 2022 |
| John Robery Limited | Information & communication | 2018 |
| John Whyte Farms Limited | Agriculture & fishing | 2020 |
| JS Pest Control Ltd | Administrative & support | 2024 |
| Jubilee Park (Wrentham) Management Company Limited | Households | 2022 |
| Juiced Sport Ltd | Arts & recreation | 2025 |
| JW Building Professional Limited | Professional & scientific | 2011 |
| JWD Limited | Agriculture & fishing | 2003 |
| K P Developments (Takeley) Limited | Construction | 2013 |
| K P Management (Takeley) Limited | Households | 2014 |
| K.C. Enterprises Limited | Professional & scientific | 1979 |
| Kalbah Ltd | Real estate | 2016 |
| Kaleidra Ltd | Information & communication | 2025 |
| Kathryn Macdonald Ltd | Health & social care | 2003 |
| Keith Egleton Company Limited | Education | 2007 |
| Keith Hall Contracting Limited | Construction | 2009 |
| Keith Westgate Gardening Services Ltd | Wholesale & retail | 2026 |
| KEN Lancaster Limited | Administrative & support | 2005 |
| Keri Newman Design Ltd | Information & communication | 2013 |
| Kevin Collyer Limited | Construction | 2003 |
| KF Footcare Ltd | Health & social care | 2023 |
| Kick a Brick Limited | Other services | 2018 |
| KLM Commercial Asset Finance Limited | Financial services | 2023 |
| Kombine Technology Limited | Financial services | 2024 |
| KONRADWELLNESS24 Limited | Information & communication | 2015 |
| Kraken Marine Solutions Limited | Professional & scientific | 2004 |
| Kroy Alloy & Autocare Ltd | Administrative & support | 2026 |
| KSR Resources Limited | Administrative & support | 2011 |
| Kulture Shock Limited | Wholesale & retail | 1997 |
| L&Z Company Business Ltd | Real estate | 2023 |
| Lads HUT Limited | Wholesale & retail | 2014 |
| Lawntech (NFK) Limited | Administrative & support | 2011 |
| Learning in Nature C.I.C. | Administrative & support | 2019 |
| Lease Cars Direct Ltd | Wholesale & retail | 2016 |
| Leggett's Farm Limited | Agriculture & fishing | 1943 |
| Leonard & Sons Limited | Wholesale & retail | 2014 |
| Lifestyle Home Appliances Ltd | Other services | 2014 |
| Lily and Jims Ltd | Wholesale & retail | 2017 |
| Lion Properties 1 Limited | Real estate | 2021 |