| KIM Doran Limited | Administrative & support | 2019 |
| Kimberly Brown Financial Services Ltd | Professional & scientific | 2018 |
| Kinder Park Nursery Services Limited | Education | 2012 |
| King Harry Estates Limited | Real estate | 2016 |
| Kingmoor Consulting Ltd | Professional & scientific | 2007 |
| Kingmoor Electrical Services Ltd | Construction | 2026 |
| Kingmoor Park Properties Limited | Real estate | 1999 |
| Kingmoor Properties Ltd | Real estate | 2025 |
| Kingmoor Property Sourcing Ltd | Real estate | 2025 |
| Kingsborough Limited | Extraterritorial | 2015 |
| Kingston Bell Properties Ltd | Real estate | 2022 |
| Kingston Project Solutions Ltd | Construction | 2025 |
| Kingstown Chef Limited | Hospitality | 2000 |
| Kinmont Rise Management Limited | Real estate | 2020 |
| Kinsella Business Solutions CIC | Administrative & support | 2024 |
| Kinsella HR Solutions Ltd | Professional & scientific | 2022 |
| KIP Carlisle & Dumfries Limited Partnership | | 2021 |
| KIP2 Limited | Real estate | 2019 |
| Kircos Limited | Transport & logistics | 2011 |
| Kirk and Stone Construction Ltd | Construction | 2021 |
| Kirkbampton Taxis Ltd | Transport & logistics | 2023 |
| Kirkland Fold Management Limited | Households | 2012 |
| Kirkland Kitchens & Interiors Limited | Wholesale & retail | 2016 |
| Kirklinton Properties Limited | Financial services | 2016 |
| Kitchen in the Courtyard Ltd | Hospitality | 2025 |
| Kitchen Wonderland Ltd | Wholesale & retail | 2022 |
| Kittoe and Co. Limited | Professional & scientific | 1985 |
| KJ Bell Ltd | Transport & logistics | 2023 |
| KJ Energy Systems Ltd | Construction | 2026 |
| Kjplp Services Ltd | Administrative & support | 2025 |
| KL Roofing Services Limited | Construction | 2025 |
| KL Subba Ltd | Hospitality | 2024 |
| KLC Estates Limited | Real estate | 2024 |
| Klein Handling Systems Limited | Administrative & support | 2006 |
| KLG Couriers Ltd | Transport & logistics | 2019 |
| KLR Building & Joinery Limited | Construction | 2011 |
| KLW Property Management Ltd | Real estate | 2020 |
| KMA Partnership Limited | Real estate | 2020 |
| Kmacc Ltd | Professional & scientific | 2021 |
| KMN Asset Management Ltd | Real estate | 2024 |
| KMO IT Ltd | Information & communication | 2025 |
| KMS Clinical Services Limited | Health & social care | 2014 |
| Knewe Biosystems UK Ltd | Professional & scientific | 2018 |
| Knipe Hall Limited | Hospitality | 2016 |
| Knowing ME ID Limited | Administrative & support | 2022 |
| Komatsu Forest Limited | Agriculture & fishing | 1996 |
| Komplex Projects UK Ltd | Professional & scientific | 2025 |
| Konstrukt-Hair Ltd | Other services | 2023 |
| Kontek Holidays Limited | | 1987 |
| Koster Aquatecnic Holdings Limited | Financial services | 2026 |
| Koster Aquatecnic Limited | Wholesale & retail | 2000 |
| KP Joinery & Builders Limited | Construction | 2016 |
| KR Estate Agents Ltd | Real estate | 2023 |
| Kratos Security and Event Staffing Limited | Administrative & support | 2026 |
| Kratos Services (England) Limited | Wholesale & retail | 2026 |
| Kratos Services Limited | Administrative & support | 2025 |
| KRM Taxi Limited | Wholesale & retail | 2026 |
| Kronen Hospitality Management Ltd | Hospitality | 2018 |
| Ksdl Trading Limited | Wholesale & retail | 2018 |
| Ksfia Ltd | Wholesale & retail | 2020 |
| Kslimbu Limited | Hospitality | 2026 |
| KTJ Solutions Limited | Construction | 2024 |
| Kudos Technical Consultancy Ltd | Professional & scientific | 2015 |
| Kurtz-Williams Limited | Transport & logistics | 2025 |
| Kutchenhaus Carlisle Ltd | Professional & scientific | 2025 |
| KVL SKN Ltd | Wholesale & retail | 2023 |
| KVT Kitchen & Bar Supplies Limited | Wholesale & retail | 2025 |
| Kwaremont Developments Ltd | Construction | 2023 |
| KYM Allan Health and Safety Consultants Limited | Other services | 2011 |
| L & a Nurseries Ltd | Health & social care | 2019 |
| L & D Riverside Properties Limited | Real estate | 2003 |
| L & K Maycock Ltd | Hospitality | 2018 |
| L C Longtown Ltd | Administrative & support | 2009 |
| L D Associates Limited | Professional & scientific | 2019 |
| L F D Group Limited | Extraterritorial | 2006 |
| L K P Consultancy Limited | Professional & scientific | 2017 |
| L K P Holdings Limited | Financial services | 2020 |
| L Kelton Limited | Real estate | 2010 |
| L N Margerison Medical Services Limited | Health & social care | 2012 |
| L&B Logs Limited | Wholesale & retail | 2023 |
| L&D DRY Stone Walling Limited | Construction | 2024 |
| L&E Farming Limited | Financial services | 2025 |
| L&L Project Management Limited | Professional & scientific | 2021 |
| L&S Cumbria Ltd | Wholesale & retail | 2024 |
| L. a. (Cockermouth) Limited | Hospitality | 2018 |
| L. a. Joinery (Carlisle) Ltd | Construction | 2017 |
| L.A Deliveries Ltd | Transport & logistics | 2023 |
| L.I. Knights Limited | Real estate | 2025 |
| L.Woolston Ltd | Hospitality | 2024 |
| LA Llorona Ltd | Hospitality | 2024 |
| LA Pizza Time Limited | Hospitality | 2017 |
| LA Rouge Hospitality Limited | Hospitality | 2023 |
| LAB Cumbria Limited | Extraterritorial | 2016 |
| LAC Logistics Ltd | Transport & logistics | 2025 |
| Lady Anne Court (Penrith) Management Company Limited | Households | 2008 |
| Laean Investments Limited | Wholesale & retail | 2015 |
| Laidlaw Building and Conservation Limited | Construction | 2025 |
| Laidlaw Scaffolding Limited | Construction | 2025 |
| Laing Timber Products Limited | Manufacturing | 2017 |
| Laings Carlisle Ltd | Hospitality | 2023 |