| Julia Holt Consulting Ltd | Professional & scientific | 2019 |
| Julia Lenihan Limited | Professional & scientific | 2024 |
| Julie SLT Ltd | Education | 2014 |
| Jumbo Faith Investment (UK) Limited | Real estate | 2007 |
| Jumook KIM Ltd | Administrative & support | 2018 |
| Jump Start Global Wine Solutions Limited | Professional & scientific | 2005 |
| Junco Ltd | Other services | 2021 |
| Junnie Care Services Ltd | Health & social care | 2024 |
| Juno Glass Limited | Construction | 1986 |
| Jupiter Leeson Limited | Real estate | 2024 |
| Jurassica OIL & GAS Ltd | Mining & quarrying | 2006 |
| Just 4 Kicks Soccer School Limited | Arts & recreation | 2004 |
| Just Healthy Chef Ltd | Hospitality | 2019 |
| Just My PA Ltd | Health & social care | 2015 |
| Just My PA Properties Ltd | Real estate | 2020 |
| Just Stay Properties Limited | Real estate | 2022 |
| Justgiftme Ltd | Wholesale & retail | 2018 |
| Jutrel Limited | Professional & scientific | 2017 |
| JW Film Production Limited | Information & communication | 2019 |
| JWW Design Limited | Information & communication | 2012 |
| K Johnston Ltd | Professional & scientific | 2023 |
| K Strategy Limited | Financial services | 2020 |
| K T Heating Services UK Ltd | Construction | 2023 |
| K&D Removals Ltd | Transport & logistics | 2021 |
| K&S Limited | Real estate | 2025 |
| K-Sing Ltd | Information & communication | 2024 |
| K. C. Curtains & Blinds Ltd. | Manufacturing | 1998 |
| K10 Studios Limited | Information & communication | 2013 |
| KA & MAN Investment Ltd | Real estate | 2021 |
| KA Highway Maintenance Ltd | Construction | 2026 |
| KA Innovation Solutions Limited | Professional & scientific | 2020 |
| Kaas Trading Ltd | Other services | 2017 |
| Kahts Properties UK Ltd | Real estate | 2021 |
| Kaikaku Ltd | Professional & scientific | 2019 |
| Kairos Exclusive London Ltd | Arts & recreation | 2025 |
| Kaizen Shore UN Limited | Financial services | 2025 |
| Kalari Limited | Education | 2019 |
| Kalasona Limited | Professional & scientific | 2018 |
| Kalido Private Ltd | Professional & scientific | 2014 |
| Kamalams Food Ltd | Wholesale & retail | 2024 |
| Kamil Digital Ltd | Information & communication | 2024 |
| Kantara Holdings Ltd | Financial services | 2025 |
| Kaplogistic Ltd | Transport & logistics | 2018 |
| Karans Engineering Ltd | Professional & scientific | 2017 |
| Karfix Limited | Wholesale & retail | 2007 |
| Karib Enterprises Limited | Hospitality | 2016 |
| Kartech Maritime Services Ltd | Manufacturing | 2017 |
| Kaskelen Ltd | Administrative & support | 2024 |
| Kast Realty Limited | Real estate | 2025 |
| Kastara Ltd | Information & communication | 2023 |
| Kavanagh-Rose Skin & Beauty Ltd | Other services | 2025 |
| Kavel Holdings Ltd | Financial services | 2020 |
| Kavel Property Ltd | Households | 2020 |
| Kayal Limited | Real estate | 2013 |
| Kazmassets Ltd | Real estate | 2024 |
| KBH Services Limited | Professional & scientific | 2009 |
| Kbma Investments Ltd | Real estate | 2023 |
| KBO Marketing Ltd | Professional & scientific | 2020 |
| KC Dental Ltd | Health & social care | 2019 |
| Kebir Turkish Kitchen Limited | Wholesale & retail | 2024 |
| Keely Consultancy Limited | Professional & scientific | 2023 |
| Keen AS Mustard Marketing Limited | Professional & scientific | 2006 |
| Keep Lookin UP Ltd | Hospitality | 2022 |
| Keiana Limited | Hospitality | 2012 |
| Kejuca Ltd | Professional & scientific | 2019 |
| Keluo UK Ltd | Wholesale & retail | 2020 |
| Kemptonpark Trucks Ltd | Wholesale & retail | 2025 |
| KEN 666 Ltd | Construction | 2022 |
| Kenovan Dominic Francis Ltd | Wholesale & retail | 2026 |
| Kenzi Advisory Ltd | Professional & scientific | 2017 |
| Kenzi Capital Ltd | Real estate | 2018 |
| Keystone Protection Group Ltd | Administrative & support | 2026 |
| Kgtravelexec Limited | Administrative & support | 2016 |
| KHP Consulting Limited | Administrative & support | 2024 |
| Khurana Food and Drinks Limited | Wholesale & retail | 2021 |
| Khurana Superstore Limited | Wholesale & retail | 2018 |
| Kildare Properties Ltd | Real estate | 2023 |
| Kindred Psychotherapy Ltd | Health & social care | 2025 |
| King & Allen Limited | Manufacturing | 2007 |
| Kings Keep Freehold Ltd | Households | 2013 |
| Kings Penny House Freehold Limited | Households | 2021 |
| Kings Penny Management Limited | Households | 2004 |
| Kingsand Estate Limited | Real estate | 2015 |
| Kingston (Sinclair Court) Management Limited | Households | 1998 |
| Kingston Accountants Ltd | Professional & scientific | 2009 |
| Kingston Agricom Limited | Other services | 2006 |
| Kingston and London Minicabs Limited Limited | Transport & logistics | 2018 |
| Kingston Aviation Holdings Limited | Professional & scientific | 2007 |
| Kingston Bathrooms Limited | Wholesale & retail | 2011 |
| Kingston Burrowes Audit Ltd | Professional & scientific | 2024 |
| Kingston Burrowes Developments Ltd | Financial services | 2022 |
| Kingston Burrowes Finance Ltd | Financial services | 2017 |
| Kingston Burrowes Property Ltd | Real estate | 2017 |
| Kingston Business Advisors Limited | Professional & scientific | 2016 |
| Kingston Carers' Network | Health & social care | 2013 |
| Kingston Caterers Ltd | Hospitality | 2019 |
| Kingston Coin Company Limited | Other services | 2012 |
| Kingston Kitchens Limited | Construction | 2005 |
| Kingston Mortgages Limited | Financial services | 2023 |
| Kingston Road, Tolworth (the Willows) Management Company Limited | Households | 1996 |