| JBS Financial Services & Consultancy Ltd | Professional & scientific | 2024 |
| Jennie White Tutoring Ltd | Education | 2024 |
| Jennifer Grace Medical Ltd | Health & social care | 2024 |
| Jeremy Weare Limited | Administrative & support | 2005 |
| JF & S Consultancy Ltd | Professional & scientific | 2012 |
| JFP Holdco Ltd | Financial services | 2023 |
| JFP Propco Ltd | Financial services | 2023 |
| JG Trading Limited | Real estate | 2014 |
| JO Henry Limited | Real estate | 2015 |
| Joanna Agrivet Ltd | Professional & scientific | 2024 |
| Jogb Limited | Manufacturing | 2016 |
| John Long Ltd | Construction | 2003 |
| John Shepherd Feeders Ltd | Manufacturing | 2013 |
| Jolly Jangles Art Ltd | Wholesale & retail | 2025 |
| JON Maine Limited | Construction | 2015 |
| Jor-Design Limited | Other services | 2024 |
| Joreba Limited | Wholesale & retail | 2015 |
| Jorgen House Ltd | Manufacturing | 2019 |
| Joshua White Ltd | Financial services | 2024 |
| JPI Consultancy Limited | Professional & scientific | 1993 |
| JS Medical Services (UK) Ltd | Health & social care | 2024 |
| JSG & Sons Limited | Professional & scientific | 2024 |
| JSW Group Ltd | Administrative & support | 2022 |
| JT Financial Support Ltd | Professional & scientific | 2017 |
| Jtfit Ltd | Arts & recreation | 2023 |
| JUB Marketing Ltd | Professional & scientific | 2025 |
| Junction Car & Commercial Ltd | Professional & scientific | 2022 |
| Juniper Park Properties Limited | Real estate | 1993 |
| Juno 1 Limited | Energy | 2025 |
| Juno 2 Limited | Energy | 2022 |
| Jupiter IX Limited | Administrative & support | 2014 |
| Justlop Limited | Professional & scientific | 1988 |
| JW Workshop Services Ltd | Wholesale & retail | 2023 |
| K a M Watson Limited | Construction | 2007 |
| K Cariad Ltd | Health & social care | 2023 |
| K D Rayson Limited | Construction | 2002 |
| Kathrine Read Osteopath Limited | Health & social care | 2003 |
| Kayse Corney Ltd | Administrative & support | 2014 |
| KD Medical Solutions Ltd | Health & social care | 2025 |
| Kenton Property Limited | Real estate | 2021 |
| Kevin Mitchell Architectural Cast Stone Limited | Manufacturing | 2017 |
| Key Ring Lettings CIC | Real estate | 2013 |
| Keystone Informatics Ltd | Information & communication | 2025 |
| Kiln Close Residents Limited | Households | 2018 |
| Kimbourne Flats Limited | Households | 1984 |
| Kingfisher Holdings (SW) Ltd | Financial services | 2024 |
| Kings Castle (Wells) Ltd | Real estate | 2015 |
| Klpm Limited | Administrative & support | 2006 |
| Knapps Farm Retreats Ltd | Hospitality | 2026 |
| Knowl Green Solar Park Limited | Energy | 2021 |
| KRM Support Ltd | Professional & scientific | 2025 |
| KT Medical Services Ltd | Health & social care | 2024 |
| Kubus Polish Ltd | Wholesale & retail | 2017 |
| L X Trix Limited | Professional & scientific | 2007 |
| L&D Garage Four Ltd | Wholesale & retail | 2023 |
| L&D Garage Ltd | Wholesale & retail | 2022 |
| L.Sealey & SON Limited | Agriculture & fishing | 1957 |
| LA Sanitas Ltd | Arts & recreation | 2023 |
| Lakeside Lettings Somerset Ltd | Real estate | 2019 |
| Landlegend Tractors Limited | Administrative & support | 2009 |
| Late Night Refreshments Ltd | Wholesale & retail | 2025 |
| Laura Vidinaru Ltd | Health & social care | 2021 |
| Laura&Karina Ltd | Health & social care | 2023 |
| Laurentiu Sirdea Zaharie Ltd | Health & social care | 2023 |
| Lazy Dogs Trading Ltd | Hospitality | 2024 |
| Lechtech Ltd | Professional & scientific | 2023 |
| Leisure Pubs Ltd | Hospitality | 2025 |
| Let's GET Quizzical Ltd | Arts & recreation | 2023 |
| Letterbox Redd Ltd | Hospitality | 2020 |
| Lewis James Financial Planning Limited | Professional & scientific | 2015 |
| Lewis Residentials Ltd | Real estate | 2026 |
| Lexy Support Ltd | Health & social care | 2018 |
| LF Imaging Ltd | Health & social care | 2023 |
| Light AGE Networks Limited | Information & communication | 2014 |
| Lily Property Services Somerset Limited | Households | 2015 |
| Lime Repair Ltd | Construction | 2008 |
| Lincoln Weston Ltd | Professional & scientific | 2026 |
| Lipswill Limited | Households | 1989 |
| Literally Shepton CIC | Education | 2020 |
| Little Becks Renewables Limited | Energy | 2025 |
| Little Brooks Lane Limited | Households | 2015 |
| Little Green Garden Shed Limited | Real estate | 2015 |
| Little Laver Renewables Limited | Energy | 2025 |
| Littlewick Property Limited | Real estate | 2018 |
| LK Medic Services Ltd | Health & social care | 2023 |
| Lloyd Fleming Plumbing and Heating Limited | Construction | 2008 |
| Lloyd Restoration Ltd | Construction | 2017 |
| LMA Logistics Ltd | Transport & logistics | 2025 |
| Loft Insulation GB Limited | Construction | 2023 |
| Longhill Accounting Limited | Professional & scientific | 2011 |
| Longwoods Livestock Limited | Agriculture & fishing | 2026 |
| Loom Designs Limited | Wholesale & retail | 2021 |
| Lorwell-Ai Ltd | Information & communication | 2025 |
| Lotus Event Solutions Ltd | Administrative & support | 2026 |
| Lower Silk Mill Management Company Limited | Professional & scientific | 2000 |
| Lower Wyke Farm Solar Park Limited | Energy | 2020 |
| Lowwall Property Management Limited | Households | 1982 |
| Lulacro Limited | Other services | 2015 |
| Lumos Property Limited | Real estate | 2017 |
| Lunanhead Renewables Limited | Energy | 2025 |