| K Euro Ltd | Wholesale & retail | 2015 |
| K&A London Contracts Limited | Construction | 2018 |
| K&F Transport Ltd | Transport & logistics | 2025 |
| K.G Management Solutions Ltd | Construction | 2015 |
| K.Taylor Consulting Limited | Administrative & support | 2015 |
| K45 Limited | Professional & scientific | 2013 |
| Kaakyire Entreprise Ltd | Other services | 2018 |
| Kabasambu Limited | Wholesale & retail | 2022 |
| Kabod Housing Ltd | Real estate | 2025 |
| Kacakike Kucukoocoo PVT Limited | Wholesale & retail | 2024 |
| Kaevelon Limited | Construction | 2024 |
| Kaheel Food Trading Ltd | Wholesale & retail | 2019 |
| KAI Technologies Limited | Information & communication | 2016 |
| Kami Spirits Limited | Wholesale & retail | 2024 |
| Kamjola Properties Ltd | Real estate | 2021 |
| KANDELHOUSING1 Limited | Real estate | 2023 |
| Kardes Hamza Limited | Hospitality | 2025 |
| Karendavis Limited | Professional & scientific | 2019 |
| Karis Services Limited | Transport & logistics | 2015 |
| Karma Pahadi Sherpa HGV Transports UK Ltd | Transport & logistics | 2020 |
| Kartar Associates Limited | Real estate | 2019 |
| Kartar ASSOCIATES2 Ltd | Real estate | 2024 |
| Kata Properties Ltd | Real estate | 2025 |
| Katrina Collier Limited | Administrative & support | 2009 |
| Katzhampers Ltd | Wholesale & retail | 2025 |
| Kavier Hair Ltd | Wholesale & retail | 2026 |
| Kavzee Ltd | Health & social care | 2025 |
| Kawasaki Ltd | Professional & scientific | 2024 |
| KAY and BEE Ltd | Wholesale & retail | 2026 |
| KAY Fashion Ltd | Wholesale & retail | 2023 |
| KAY Property Solution Ltd | Real estate | 2022 |
| Kays Classic Property Limited | Real estate | 2023 |
| Kaytrix Care Services and Training Ltd | Administrative & support | 2017 |
| Kaytrix Tempratech Ltd | Construction | 2024 |
| KAZ International Ltd | Wholesale & retail | 2018 |
| KCJ Ltd | Real estate | 2018 |
| KD Property&Co Ltd | Real estate | 2025 |
| Kemorah London Ltd | Other services | 2018 |
| Kenie Limited | Health & social care | 2022 |
| Kent Commercials Limited | Transport & logistics | 1982 |
| Kent Powder Coating Limited | Manufacturing | 2006 |
| Kent Precision Products Limited | Manufacturing | 1995 |
| Kent Self Storage Limited | Transport & logistics | 2014 |
| Kentish Maid Ltd | Manufacturing | 2017 |
| Kept Property Group Ltd | Hospitality | 2026 |
| Kershaw Contracting Services Limited | Construction | 1972 |
| Keskem Limited | Public administration | 2022 |
| Kess Paradise Hair and Beauty Limited | Other services | 2023 |
| Kevisha Limited | Health & social care | 2011 |
| Kfosu Care Limited | Health & social care | 2016 |
| KFX Trading Ltd | Financial services | 2025 |
| KG Hardlandscaping Ltd | Administrative & support | 2025 |
| Khyb Ltd | Information & communication | 2025 |
| KI Global Services Ltd | Professional & scientific | 2024 |
| KI Rail Ltd | Construction | 2024 |
| KID Services Limited | Health & social care | 2008 |
| Kidbus Ltd | Transport & logistics | 2013 |
| Kiddie Steps Daycare Ltd | Health & social care | 2025 |
| Kiddies Palace Nursery Ltd | Education | 2020 |
| Kiddies Place Limited | Professional & scientific | 2021 |
| Kiddies World Childcare Limited | Health & social care | 2025 |
| Kids Fingers and Thumbs Ltd | Wholesale & retail | 2020 |
| Kidz Exclusive Ltd | Wholesale & retail | 2019 |
| Kilimanjara Ltd | Wholesale & retail | 2018 |
| Kimi Kitty Ltd | Wholesale & retail | 2019 |
| Kimona Maternity Services Limited | Health & social care | 2018 |
| Kinetic IT (Holdings) Limited | Financial services | 2018 |
| Kinetic IT Limited | Information & communication | 2010 |
| Kings Highway Garage Limited | Wholesale & retail | 1960 |
| Kingsley Transport Logistics Ltd | Transport & logistics | 2015 |
| Kingswell Trading Ltd | Wholesale & retail | 2026 |
| KIP Mcgrath Erith, Welling and Dartford LLP | | 2024 |
| Kirat Noor Transport Ltd | Transport & logistics | 2022 |
| Kisito Limited | Health & social care | 2022 |
| KK & AA Limited | Health & social care | 2018 |
| KKS Scaffolding Limited | Construction | 1991 |
| Klarity Accounting Services Ltd | Professional & scientific | 2022 |
| Klazz Trading Limited | Wholesale & retail | 2021 |
| KLB Services South East Limited | Information & communication | 2025 |
| Kleen Facility Services Ltd | Real estate | 2021 |
| KLM Real Estate Ltd | Real estate | 2020 |
| KLS Magpie Limited | Professional & scientific | 2015 |
| KM Chernev Ltd | Construction | 2014 |
| Kmeetwell Limited | Wholesale & retail | 2025 |
| Kmoney Projects UK Ltd | Construction | 2014 |
| KMS Transport Services Ltd | Transport & logistics | 2025 |
| Known Event Centre Ltd | Information & communication | 2023 |
| Known Properties Ltd | Real estate | 2017 |
| Koil Plta Limited | Hospitality | 2025 |
| Koko & Konan Ltd | Wholesale & retail | 2022 |
| Koko & Konan Property Management Ltd | Real estate | 2022 |
| Kolarto Consulting Limited | Professional & scientific | 2011 |
| Kole Investment Company Limited | Real estate | 2016 |
| Kole Investment Group Ltd | Construction | 2023 |
| Kolyphe Ltd | Hospitality | 2019 |
| Kort Propulsion Company Limited | Manufacturing | 1935 |
| Kotarja Construction Ltd | Construction | 2024 |
| Kramfors Ltd | Administrative & support | 2016 |
| Ktsn Ltd | Health & social care | 2023 |
| KTZ Security Ltd | Administrative & support | 2022 |