| JT Home Holdings Ltd | Real estate | 2021 |
| JT Marketing Consultancy Ltd | Professional & scientific | 2023 |
| JT OIL and GAS Limited | Professional & scientific | 2021 |
| Jtape Limited | Manufacturing | 2003 |
| JTEL84 Limited | Arts & recreation | 2023 |
| JTF Property Services Limited | Construction | 2020 |
| Jubel Life Ltd | Wholesale & retail | 2023 |
| Julian Cooper Limited | Professional & scientific | 1999 |
| Julienne Properties Limited | Real estate | 2020 |
| Juliet Prescott Psychological Services Limited | Health & social care | 2017 |
| Juno Services Limited | Information & communication | 2016 |
| Just ASK Newton Ltd | Wholesale & retail | 2025 |
| Just Astons Ltd | Wholesale & retail | 2025 |
| Just Blue OR Pink Ltd | Wholesale & retail | 2021 |
| Just Drop-In Youth Info & Advice Limited | Health & social care | 1999 |
| Just Financial Solutions Limited | Information & communication | 2018 |
| Just LA Manga Club Limited | Administrative & support | 2011 |
| Just MSC Limited | Financial services | 2020 |
| Just Resorts Limited | Administrative & support | 2010 |
| Justco Ltd | Other services | 2006 |
| Juste Properties Limited | Households | 2018 |
| Justin Saunders Consulting Ltd | Information & communication | 2017 |
| JW Hulme Limited | Financial services | 2022 |
| Jwashpro Ltd | Administrative & support | 2024 |
| JWR Plumbing and Heating Limited | Construction | 2024 |
| JWS Prestige Ltd | Wholesale & retail | 2023 |
| JWT Limited | Construction | 2001 |
| JWT Macclesfield Limited | Real estate | 2025 |
| K & I Lawrence Limited | Administrative & support | 2000 |
| K Dilkes Property Ltd | Real estate | 2025 |
| K F Equestrian Ltd | Agriculture & fishing | 2017 |
| K J Plant Developments Limited | Construction | 2006 |
| K S Whittaker Plastering Ltd | Construction | 2009 |
| K Whylie & SON Limited | Construction | 2012 |
| K&R Health Suites Limited | Real estate | 2020 |
| K-Tech Plastics Machinery Limited | Wholesale & retail | 2008 |
| K.C. Pettener Properties Limited | Real estate | 1990 |
| K.C.Pettener & Co.Limited | Financial services | 1971 |
| Ka&D Developments Limited | Administrative & support | 2017 |
| Kaam Limited | Real estate | 2018 |
| Kaisoft Limited | Information & communication | 2018 |
| Kaleidoscope Concepts Limited | Professional & scientific | 2015 |
| Kaliber Group Limited | Financial services | 2017 |
| Kals Property Limited | Financial services | 2019 |
| KAN DO Sports Ltd | Education | 2022 |
| KAN DO Ventures Ltd. | Professional & scientific | 2014 |
| Kandara Candles Limited | Manufacturing | 2020 |
| Kandyrestaurant Limited | Hospitality | 2018 |
| Kaninhål Records Ltd | Wholesale & retail | 2025 |
| Kanman Regen Ltd | Health & social care | 2025 |
| Kapabl Limited | Information & communication | 2026 |
| Kapi Communications & Consultancy Limited | Professional & scientific | 2018 |
| Kaptins Limited | Real estate | 2017 |
| Karachi Eats Ltd | Hospitality | 2026 |
| Karen Hyde Ltd | Professional & scientific | 2014 |
| Karglen Contracts Limited | Construction | 1981 |
| Karleen Nicholson Communications Ltd | Administrative & support | 2015 |
| Karon Beighton Estate Agents Ltd | Real estate | 2025 |
| Kars Properties Limited | Real estate | 2026 |
| Kash Trading Limited | Wholesale & retail | 2019 |
| Kathryn Woods Medical Writing Ltd | Professional & scientific | 2021 |
| Katuk Limited | Manufacturing | 2020 |
| Kauto Developments Ltd | Real estate | 2018 |
| Kava Group Ltd | Financial services | 2023 |
| Kayelcee Ltd | Professional & scientific | 2024 |
| Kayjay Productions Ltd | Hospitality | 2025 |
| KD Podiatry Limited | Health & social care | 2026 |
| Keenrick Limited | Real estate | 1984 |
| Kelcam Broadcast Ltd | Information & communication | 2023 |
| Kelleys DRY Cleaning Services Limited | Administrative & support | 2012 |
| Kelly Prior Limited | Professional & scientific | 2010 |
| KEM Group Holdings Ltd | Hospitality | 2021 |
| Kemac Services Limited | Extraterritorial | 2012 |
| Kendrew Pine Limited | Professional & scientific | 2013 |
| Kendrew Pine Prestbury LLP | | 2014 |
| Kennie and Co Ltd | Wholesale & retail | 2023 |
| Kent Osbourne Quality Builders Ltd | Construction | 2013 |
| Kentish Engineering Consulting Ltd | Professional & scientific | 2015 |
| Kerfoot Property Ltd | Real estate | 2022 |
| Kerridge END Parking Scheme Limited | Households | 2003 |
| Kevat Solar Limited | Energy | 2012 |
| Kevin Plant Developments Ltd | Construction | 2020 |
| KEW Books Limited | Wholesale & retail | 2002 |
| Key Wealth Management Ltd | Financial services | 2013 |
| Keystone Construction Services Ltd | Construction | 2025 |
| KF Services Cheshire Limited | Professional & scientific | 2014 |
| Kgrh Group Ltd | Wholesale & retail | 2025 |
| KH Medical Limited | Health & social care | 2022 |
| Kickondotcom Ltd | Agriculture & fishing | 2022 |
| Kieran Hibbs Architecture Ltd | Professional & scientific | 2020 |
| Kieran Moss Financial Limited | Financial services | 2015 |
| Kilam Capital Ltd | Extraterritorial | 2022 |
| Kime O'Brien Limited | Professional & scientific | 2003 |
| King & Co Property Ltd | Real estate | 2025 |
| King's School Macclesfield Limited | Administrative & support | 2022 |
| Kingdom Decals Ltd | Wholesale & retail | 2022 |
| Kingdom Dream Ltd | Real estate | 2023 |
| Kinnerton Meadows Management Limited | Construction | 2018 |
| Kinomica Limited | Professional & scientific | 2016 |
| Kinsella & Sons LLP | | 2016 |