| Kampez Limited | Information & communication | 2005 |
| Kams Estates Limited | Real estate | 2024 |
| Kamuran K Properties Ltd | Real estate | 2025 |
| Kanishkar Ltd | Information & communication | 2013 |
| Kannan Process Consultants Limited | Administrative & support | 2008 |
| Kannan Stores Limited | Wholesale & retail | 2008 |
| Kanyaa Ltd | Wholesale & retail | 2024 |
| Kapadia Partners Limited | Real estate | 2025 |
| Kapi Global Limited | Wholesale & retail | 2020 |
| Kapital Management Groupe Ltd | Professional & scientific | 2023 |
| Kapiti Translations Ltd | Professional & scientific | 2022 |
| Kapo Ltd | Real estate | 2017 |
| Karao TV Ltd | Information & communication | 2023 |
| Karen Murphy Limited | Health & social care | 2019 |
| Karen's Records Ltd | Information & communication | 2019 |
| Karia Keys Ltd | Real estate | 2026 |
| Karina Estates Limited | Real estate | 2025 |
| Karis Capital Limited | Financial services | 2017 |
| Karis Holdings Limited | Financial services | 2022 |
| Karis Insurance Brokers Limited | Financial services | 2023 |
| Karmi Consultancy Limited | Health & social care | 2014 |
| Kartel Club Ltd | Administrative & support | 2025 |
| Kash & Sons Limited | Real estate | 2005 |
| Kashish Ltd | Health & social care | 2020 |
| Kassa Property Development UK Ltd | Construction | 2019 |
| KAT Consulting Ltd | Administrative & support | 2019 |
| Katayoon Limited | Professional & scientific | 2014 |
| Katherine Moonan Ltd | Information & communication | 2012 |
| Kathy Data Ltd | Information & communication | 2019 |
| Kati Patang Limited | Administrative & support | 2023 |
| Katie Baccouche Advisory Ltd | Administrative & support | 2024 |
| Katikia Investments Limited | Real estate | 2022 |
| KAV Plus Limited | Wholesale & retail | 2015 |
| Kavegan Iran Limited | Other services | 2018 |
| Kavita M Consultancy Ltd | Professional & scientific | 2024 |
| Kavnila Properties Ltd | Real estate | 2025 |
| KAY and EM Limited | Real estate | 2002 |
| Kazere Property Investment Limited | Real estate | 2024 |
| KBM Design and Build Ltd | Construction | 2025 |
| KBV London Ltd | Construction | 2013 |
| KC Powertrain System Ltd | Wholesale & retail | 2019 |
| KCH Contractors Limited | Construction | 2004 |
| Kcis London Ltd | Real estate | 2018 |
| KCJ Builders London Limited | Construction | 2018 |
| Kcrm Ltd | Real estate | 2008 |
| KCS Cleaning Limited | Other services | 2025 |
| KCS Weld Limited | Construction | 2019 |
| KD Services (UK) Ltd | Professional & scientific | 2014 |
| KDN Associates Ltd | Health & social care | 2014 |
| KDT Studios Ltd | Wholesale & retail | 2025 |
| Kdym Ltd | Arts & recreation | 2024 |
| KE Construction Limited | Construction | 2020 |
| Keates Lodge (North) Management Co. Limited | Households | 1996 |
| Keats Lodge (South) Management Co. Limited | Households | 1997 |
| Kebabg Limited | Hospitality | 2017 |
| Keenspace Self Storage (Kettering) Ltd | Transport & logistics | 2026 |
| Keep Compliance Healthy (KCH) Portal Ltd | Professional & scientific | 2025 |
| Kegler Ltd | Professional & scientific | 2010 |
| Kehinde Care Services Limited | Health & social care | 2014 |
| Keldrick Holdings Limited | Administrative & support | 2020 |
| Kelly & Kelly Property Limited | Real estate | 2013 |
| Kelly Gibbons & Sons Limited | Real estate | 2021 |
| Keltic Taverns Limited | Hospitality | 2018 |
| KEM Financial Services Limited | Financial services | 2022 |
| KEN Commercial Services Limited | Wholesale & retail | 1975 |
| Kene Property Rentals Ltd | Real estate | 2015 |
| Kenley Close Management Limited | Households | 1983 |
| Kennedys Tooting Limited | Hospitality | 2020 |
| Kenology Arts Ltd | Arts & recreation | 2026 |
| Kenoo Limited | Hospitality | 2026 |
| Kensington Intl (Logistics) Ltd | Other services | 2026 |
| Kensington Intl (UK) Ltd | Wholesale & retail | 2026 |
| Kensington Waste Management Limited | Administrative & support | 2022 |
| Kent Piano Movers Limited | Transport & logistics | 2026 |
| Kent Pianos Limited | Wholesale & retail | 2026 |
| Kentish Town Banqueting Limited | Arts & recreation | 2020 |
| Kenward Global Ltd | Professional & scientific | 2023 |
| Kenworth Traders Ltd | Other services | 2014 |
| Keogh Group UK Ltd | Real estate | 2024 |
| Keppenburn Limited | Information & communication | 2015 |
| Keramos Consulting Limited | Professional & scientific | 2019 |
| Kermitclouds Ltd | Wholesale & retail | 2022 |
| Kerry GAA Trust | Arts & recreation | 2025 |
| Kerylos Limited | Information & communication | 1994 |
| Kesk Transport Ltd | Transport & logistics | 2024 |
| Keto Group Ltd | Hospitality | 2018 |
| Kettle Club London Limited | Wholesale & retail | 2024 |
| Kevin Denim Limited | Administrative & support | 2017 |
| Kevin Watson Construction Ltd | Construction | 1993 |
| Kevin Watson Properties Limited | Real estate | 1996 |
| KEW Avenue Developments Limited | Construction | 2013 |
| Key Commodities Ltd | Hospitality | 2023 |
| Key Currency Limited | Financial services | 2015 |
| Key Sector Recruitment (Midlands) Ltd | Administrative & support | 2019 |
| Keylending Limited | Administrative & support | 2011 |
| Keystone Analytics Limited | Information & communication | 2016 |
| Keystone Retrofit Group Ltd | Construction | 2026 |
| Keystone Talent Limited | Administrative & support | 2023 |
| Keyvani Clinic Ltd | Health & social care | 2026 |
| Keyvani Limited | Real estate | 2023 |