| Hicky Estates Ltd | Real estate | 2022 |
| High Path VAT Consultancy Limited | Extraterritorial | 2011 |
| Highwood Associates LLP | | 2025 |
| Hire That Ltd | Information & communication | 2023 |
| Hire That Money Ltd | Financial services | 2012 |
| Holcombe's of Taunton Limited | Wholesale & retail | 2019 |
| Holdsworth Estates Ltd | Real estate | 2021 |
| Holman Clavel Inn Ltd | Hospitality | 2019 |
| Holocroncard Ltd | Wholesale & retail | 2019 |
| Holsworthy Limited | Transport & logistics | 2000 |
| Home From Home Properties Limited | Real estate | 2025 |
| Honesty Box Payments Ltd | Information & communication | 2020 |
| Honeysuckle Construction Limited | Construction | 2018 |
| Hong Natural Therapy Centre Ltd | Other services | 2026 |
| Hoppity Hollow Ltd | Arts & recreation | 2025 |
| Hydramarine Services Ltd | Professional & scientific | 2019 |
| Hydramatic (Somerset) Limited | Professional & scientific | 2008 |
| I.M. Mitchell Farming Limited | Agriculture & fishing | 2012 |
| IAN Fredericks Construction Consultancy Limited | Construction | 2009 |
| Igukro Limited | Professional & scientific | 2024 |
| Immigration Compliance Ltd | Professional & scientific | 2020 |
| Impactra Healthcare Ltd | Health & social care | 2026 |
| Inclusive Education Consultancy Ltd | Education | 2023 |
| Independent Professional Trustees (2008) Ltd | | 2023 |
| Indica Automotive Limited | Manufacturing | 2014 |
| Indica Industries UK Limited | Administrative & support | 2014 |
| Indigo Care Limited | Extraterritorial | 2022 |
| Infinite Property Group Limited | Real estate | 2016 |
| Inpatiria Limited | Administrative & support | 2021 |
| Integra PDU Limited | Manufacturing | 2018 |
| Intent Interiors Ltd | Administrative & support | 2024 |
| Interiors and Flowers by Design LLP | | 2007 |
| Interstellar Ideas Ltd | Wholesale & retail | 2020 |
| IPM Royale | | 1999 |
| J & D Agriculture Limited | Agriculture & fishing | 2023 |
| J a O Groundworks Ltd | Construction | 2019 |
| J C Autos Bridgwater Ltd | Wholesale & retail | 2019 |
| J Croft Contracting Ltd | Construction | 2023 |
| J Wooff Construction Ltd | Construction | 2022 |
| J Wooff Holdings Ltd | Financial services | 2025 |
| J&R Automotive Ltd | Wholesale & retail | 2024 |
| J17 Projects Ltd | Other services | 2011 |
| Jacob's Civil Engineering Solutions Limited | Construction | 2018 |
| JAM Bidco Limited | Manufacturing | 2014 |
| JAM Topco Limited | Manufacturing | 2014 |
| Jamesalexandercontracts Ltd | Construction | 2021 |
| Jameswell Investments Ltd | Professional & scientific | 2006 |
| Jamie Carter Limited | Wholesale & retail | 2012 |
| JAO Holdings Limited | Financial services | 2023 |
| Jces Holdings Ltd | Financial services | 2024 |
| Jdcenergy Limited | Professional & scientific | 2015 |
| JDM Regiment Ltd | Wholesale & retail | 2021 |
| Jeffrey Limited | Real estate | 2015 |
| JETWASH4U Ltd | Administrative & support | 2022 |
| JFM Safety Nets Limited | Construction | 2025 |
| JG Wellington Limited | Hospitality | 2020 |
| JHR Property Consultants Limited | Professional & scientific | 2025 |
| Jinzhou Limited | Professional & scientific | 2002 |
| JMT Plastering Limited | Construction | 2013 |
| JO Southcombe Limited | Real estate | 2017 |
| John Blake Hydrams Limited | Professional & scientific | 2006 |
| Jolly Green Frogs Limited | Information & communication | 2024 |
| Jonathan Bowen Consulting Ltd | Professional & scientific | 2025 |
| Joseph Welch Jewellers Limited | Wholesale & retail | 2012 |
| JR & AE Carter Innovations LLP | | 2012 |
| Jt&C the Knowledge Group Ltd | Professional & scientific | 2008 |
| Just Used Machinery Ltd | Wholesale & retail | 2007 |
| K & B Barber (SW) Ltd | Other services | 2024 |
| K & P Maitland Limited | Real estate | 1975 |
| K D J Driving Ltd | Transport & logistics | 2020 |
| K.W. White & Sons Limited | Agriculture & fishing | 1972 |
| Kamyko Ltd | Other services | 2012 |
| Kanya Care Ltd | Health & social care | 2022 |
| Karesa Construction Ltd | Construction | 2012 |
| Karesa Developments Ltd | Construction | 2004 |
| Karesa Timber Frame Ltd | Construction | 2022 |
| Kaur Properties Limited | Real estate | 2002 |
| KB Wedding Videography Ltd | Information & communication | 2021 |
| KCA Engineering Ltd | Administrative & support | 2017 |
| KCS Auto's (SW) Ltd | Wholesale & retail | 2020 |
| KDC UK Holdings Limited | Financial services | 2025 |
| Kdc/One Swallowfield Limited | Manufacturing | 2019 |
| Keith Kerslake Limited | Construction | 2002 |
| Kelos Limited | Professional & scientific | 2003 |
| Kenos Limited | Health & social care | 2015 |
| Kenso Ltd | Agriculture & fishing | 2018 |
| Kerplunk Limited | Real estate | 2021 |
| Kghd Academy Ltd | Education | 2025 |
| Kghd Ltd | Other services | 2024 |
| Kingdom TM Ltd | Manufacturing | 2015 |
| Kingfisher Packaging Limited | Administrative & support | 2014 |
| Kinglake Leadership Solutions Limited | Professional & scientific | 2022 |
| Kingsmead Centre LLP | | 2015 |
| Kingswell Beauty Ltd | Other services | 2025 |
| Kinium Consulting Limited | Real estate | 2025 |
| Kinium Developments Limited | Real estate | 2020 |
| Kitchen at the Croft Ltd | Manufacturing | 2025 |
| Kittisford Barns Management Company Limited | Administrative & support | 2007 |
| KJD Software Engineering Ltd | Information & communication | 2023 |
| KNC Consulting Limited | Information & communication | 2015 |