| Hartington Engineering Limited | Professional & scientific | 2009 |
| Harvington House Limited | Hospitality | 2017 |
| Hashtag Housing Ltd | Real estate | 2024 |
| Hawthorn Estates (Cumbria) Limited | Real estate | 1994 |
| Hayton Aviation (London) Limited | Wholesale & retail | 2023 |
| Helgar Offshore Safety Limited | Construction | 2013 |
| Henry's Bar & Grill (Workington) Limited | Hospitality | 2015 |
| Hensingham Business Park Maintenance Company Limited | Extraterritorial | 2017 |
| Hestia Homes (North) Ltd | Real estate | 2019 |
| Hewitson Engineering Services Limited | Professional & scientific | 2026 |
| Hfawcett Ltd | Wholesale & retail | 2025 |
| Hidef Aerial Surveying Limited | Professional & scientific | 2005 |
| Higgins Property Limited | Real estate | 2022 |
| High Moorside Consulting Limited | Professional & scientific | 2015 |
| High Stile Maintenance Company Limited | Households | 2022 |
| Highbury Warehouse Limited | Wholesale & retail | 2023 |
| Highnoon Limited | Real estate | 2006 |
| Hive Promotions Limited | Administrative & support | 2022 |
| HMA Health Limited | Health & social care | 2020 |
| HMW Associates Limited | Other services | 2008 |
| Hodgsons (Homeflair) Limited | Real estate | 1965 |
| Holcar Auto Services Limited | Wholesale & retail | 2002 |
| Holmen Board and Paper Limited | Manufacturing | 1902 |
| Holmen Paper Limited | Wholesale & retail | 1970 |
| Holt Welding Services Limited | Manufacturing | 2020 |
| Honister Media Ltd | Manufacturing | 2024 |
| Horizon Tile and Bathroom Centre Limited | Wholesale & retail | 2004 |
| Hospice at Home West Cumbria | Health & social care | 2001 |
| Hospice at Home West Cumbria Trading Limited | Wholesale & retail | 2007 |
| Hot Spot Property Services Ltd | Financial services | 2019 |
| Hoyland Fabrication Ltd | Construction | 2024 |
| Hudson-Swan Engineering Limited | Real estate | 1980 |
| Hughie Holdings Limited | Financial services | 2024 |
| Hugill Consulting Ltd | Professional & scientific | 2020 |
| Hunday Manor Limited | Hospitality | 2023 |
| Huntys Homes Ltd | Real estate | 2019 |
| IAN Wilson Containers Limited | Other services | 2016 |
| IAN Wilson Haulage Limited | Transport & logistics | 1999 |
| IAN Wilson Storage Limited | Transport & logistics | 2020 |
| IC Property Investments Limited | Real estate | 2018 |
| Iggesund (UK) Pensions Limited | Financial services | 1988 |
| Industrial Process & Engineering Services Limited | Manufacturing | 1994 |
| Inner Hype Ltd | Real estate | 2019 |
| Inside Tomorrow Limited | Professional & scientific | 2023 |
| Into the Black Financial Services CIC | Professional & scientific | 2025 |
| Into the Groove Ltd | Arts & recreation | 2024 |
| Intrim Fitness Centres Limited | Arts & recreation | 2002 |
| IPR Commissioning Legend Ltd | Professional & scientific | 2025 |
| Istanbul Style Ltd | Other services | 2020 |
| Iva’S Delight Limited | Hospitality | 2026 |
| J & a Lowe Ltd | Administrative & support | 2004 |
| J & S Plant (Cumbria) Limited | Administrative & support | 2001 |
| J Burrow Contracting Ltd | Agriculture & fishing | 2026 |
| J J ' S Sports Bar Ltd | Hospitality | 2018 |
| J S Racing (Cumbria) Limited | Arts & recreation | 2017 |
| J&C Maintenance Ltd | Manufacturing | 2022 |
| J.D. Lister (Furnishers) Limited | Wholesale & retail | 1973 |
| J.Proud Plastering Ltd | Construction | 2026 |
| J.T.M Engineering Consultancy Ltd | Professional & scientific | 2026 |
| Jackal Outdoors Limited | Wholesale & retail | 2012 |
| James Core Limited | Professional & scientific | 2014 |
| Jamjute Gynae Care Ltd | Health & social care | 2022 |
| Jane Pizza Ltd | Hospitality | 2018 |
| JB Property Law Ltd | Professional & scientific | 2026 |
| JD Building and Groundworks (Cumbria) Limited | Construction | 2019 |
| JDM Motorsport Ltd | Wholesale & retail | 2020 |
| JE Mechanical (North West) Limited | Professional & scientific | 2024 |
| JF Storage Limited | Administrative & support | 2024 |
| JGH Fitness Limited | Arts & recreation | 2018 |
| JGM Nuclear Advisory Limited | Professional & scientific | 2024 |
| JH Electrical Cumbria Ltd | Construction | 2026 |
| JH Planning Consultancy Limited | Administrative & support | 2023 |
| JHT Software Limited | Information & communication | 2014 |
| Jj's Pool and Snooker Bar (Members Only) Limited | Hospitality | 2022 |
| JJD Project Management Ltd | Professional & scientific | 2018 |
| JLR Properties Cumbria Ltd | Real estate | 2024 |
| JM Machplast Ltd | Construction | 2013 |
| Jmnb Holdings Ltd | Real estate | 2026 |
| Joebele Ltd | Health & social care | 2020 |
| John Quinn Logistics Ltd | Transport & logistics | 2025 |
| John Robson Properties Limited | Construction | 1997 |
| John Sandelands (Funeral Directors) Limited | Other services | 2010 |
| John Sandelands Limited | Construction | 2002 |
| John Stalker Farrier Limited | Other services | 2014 |
| Jonathan Smyth Limited | Professional & scientific | 2023 |
| Joseph Ridley Builders Limited | Construction | 2002 |
| JP Inspection Ltd | Professional & scientific | 2022 |
| JSR Property Group Ltd | Real estate | 2024 |
| JT Joinery & Carpentry Ltd | Construction | 2026 |
| Jtec Cumbria Ltd | Wholesale & retail | 2022 |
| Just Hospitality Cumbria Limited | Administrative & support | 2015 |
| JVW Engineering Ltd | Professional & scientific | 2023 |
| JW Design (Cumbria) Ltd | Professional & scientific | 2018 |
| JW Group Limited | Arts & recreation | 2020 |
| JW Music Limited | Arts & recreation | 2013 |
| JWJ Group Ltd | Arts & recreation | 2024 |
| K & K Just SO Beauty Limited | Other services | 2019 |
| K J G Developments Limited | Real estate | 2012 |
| K Norman Limited | Construction | 2014 |
| K&K Lakes Developments Ltd | Real estate | 2024 |