| Junovate Instruments Ltd. | Professional & scientific | 2014 |
| Jupiter Property Developments Limited | Construction | 2017 |
| Jura Pentium Limited | Information & communication | 2018 |
| Just a SEC (Greater Manchester) Limited | Administrative & support | 2014 |
| Just ASK Digital Marketing Ltd | Professional & scientific | 2026 |
| Just Builders (NW) Ltd | Construction | 2019 |
| Just Hazel Ltd | Administrative & support | 2023 |
| Just Helping | Other services | 2012 |
| Just SAY Analysis Limited | Administrative & support | 2021 |
| Just SAY Please Limited | Information & communication | 2000 |
| Justanotherday Consulting Limited | Professional & scientific | 2021 |
| Jutlandia Doors Limited | Wholesale & retail | 1990 |
| Juvenesco Limited | Professional & scientific | 2013 |
| Jvct Limited | Real estate | 2022 |
| Jvpf (2022) Limited | Construction | 2022 |
| Jvpf Limited | Construction | 2020 |
| JW Strategic Finance Limited | Professional & scientific | 2025 |
| JW Vintage & Luxury Ltd | Wholesale & retail | 2025 |
| Jwdp UK Ltd | Financial services | 2022 |
| JWM Investments Limited | Other services | 2023 |
| Jwsw Architecture Consulting Limited | Information & communication | 2020 |
| JZ Medics Limited | Health & social care | 2019 |
| K & F R Enterprises Limited | Hospitality | 2015 |
| K & L M Builders Limited | Construction | 2001 |
| K & R Badges Limited | Wholesale & retail | 2009 |
| K Konsultancy Limited | Professional & scientific | 2023 |
| K R Harris Consulting Limited | Professional & scientific | 2012 |
| K S Roberts Limited | Wholesale & retail | 2005 |
| K W Professionals Ltd | Health & social care | 2025 |
| K&S Business Consultancy Ltd | Administrative & support | 2013 |
| K-Kam Limited | Construction | 2019 |
| K.P. Loughran Electrical Limited | Construction | 2014 |
| K2 BI Solutions Limited | Information & communication | 2009 |
| K2A Ltd | Real estate | 2024 |
| K2M Legal Limited | Professional & scientific | 2021 |
| K3M Consulting Ltd | Professional & scientific | 2026 |
| K9 Mobility Limited | Wholesale & retail | 2024 |
| Kaaas Medical Limited | Health & social care | 2022 |
| Kaarshika Nilayam Ltd | Real estate | 2024 |
| Kaas Medical Services Ltd | Health & social care | 2012 |
| Kabesons Ltd | Real estate | 2021 |
| Kabri International General Trading UK Ltd | Wholesale & retail | 2023 |
| KAD Properties (NW) Ltd | Real estate | 2018 |
| Kaeshav Medical Limited | Real estate | 2018 |
| Kahanui 3 Limited | Wholesale & retail | 2021 |
| Kahanui 4 Limited | Wholesale & retail | 2025 |
| Kairali Foods Ltd | Wholesale & retail | 2023 |
| Kaisoms Limited | Professional & scientific | 2022 |
| Kaizen K9 Limited | Extraterritorial | 2025 |
| Kaleidoscope Solutions Limited | Information & communication | 2020 |
| Kalibr Labs Limited | Information & communication | 2026 |
| Kalita Property Management Limited | Households | 2020 |
| Kallebrink Consulting Limited | Information & communication | 2022 |
| Kallidus Bidco Limited | Information & communication | 2014 |
| Kallidus Holdings Limited | Information & communication | 2014 |
| Kallidus Intermediary Limited | Information & communication | 2014 |
| Kallidus Limited | Information & communication | 2000 |
| Kallidus Target Limited | Information & communication | 2009 |
| Kalon Medical Ltd | Health & social care | 2022 |
| Kalt Creative Limited | Information & communication | 2024 |
| KAM Chana Ltd | Health & social care | 2023 |
| Kami Buyer UK Limited | Education | 2025 |
| Kammac Limited | Transport & logistics | 1988 |
| Kamson Contracts Limited | Professional & scientific | 2024 |
| Kana Earth Limited | Information & communication | 2021 |
| Kana Nominees Limited | Extraterritorial | 2023 |
| Kangaroo Pooling Limited | Financial services | 2024 |
| Kanna Gnanalingham Ltd | Health & social care | 2019 |
| Kansho Property Limited | Construction | 2019 |
| Karam 7272 Ltd | Wholesale & retail | 2025 |
| Karen Jones Architects Limited | Professional & scientific | 2015 |
| Karen Mullins Consulting Limited | Other services | 2017 |
| Kargwell Medical Diagnostic Ltd | Health & social care | 2025 |
| Karps Diagnostics Limited | Health & social care | 2023 |
| Karzoom Limited | Administrative & support | 2019 |
| KAS Telecoms Consultancy Ltd | Professional & scientific | 2015 |
| Kast Labs (UK) Ltd | Information & communication | 2026 |
| Kate Gardner Limited | Professional & scientific | 2025 |
| Kate Lily Rose Limited | Other services | 2024 |
| Kate Tsig Ltd | Health & social care | 2025 |
| Katherine Jeffery Podiatry Limited | Health & social care | 2020 |
| Katherine Mackay Consultancy Ltd. | Professional & scientific | 2016 |
| Katie Salinger Limited | Education | 2013 |
| Kavya Holdings Limited | Professional & scientific | 2019 |
| Kawalek Ltd | Information & communication | 2017 |
| KAY Roofing (North West) Limited | Construction | 2023 |
| Kayber (Fairclough) Limited | Real estate | 2021 |
| Kayur Properties Limited | Real estate | 2021 |
| KAZ Properties Limited | Real estate | 2018 |
| KBB Design Company Limited | Wholesale & retail | 2009 |
| Kbhb Consultancy Limited | Wholesale & retail | 2021 |
| KC Strategy Consulting Limited | Professional & scientific | 2023 |
| KD Digital Services Limited | Professional & scientific | 2023 |
| KD Foods PVT Ltd | Wholesale & retail | 2025 |
| KD Prestige Holdings Ltd | Wholesale & retail | 2026 |
| KDL Consultancy Services Limited | Professional & scientific | 2022 |
| Kdmed Limited | Health & social care | 2021 |
| KDS Doors Limited | Construction | 2006 |
| KDW Developments Limited | Real estate | 2019 |
| KDW Partnerships Limited | Construction | 2019 |