| JRL Property (Sandy) Limited | Real estate | 2019 |
| JRL Property (Skelmersdale) Limited | Real estate | 2020 |
| JRL Property (Southwark) Limited | Real estate | 2015 |
| JRL Property (Sutton) Ltd | Construction | 2019 |
| JRL Property (Trent) Limited | Real estate | 2010 |
| JRL Property (Whittlesey) Limited | Real estate | 2016 |
| JRL Property (Woking 2) Ltd | Construction | 2024 |
| JRL Property (Woking) Ltd | Construction | 2015 |
| JRL Property Holdings Limited | Financial services | 2017 |
| JRL Property Limited | Real estate | 2003 |
| JRL Structures Limited | Construction | 2017 |
| JRL Trading (3) Ltd | Construction | 2021 |
| JRL Woking Gateway Limited | Real estate | 2021 |
| Jryb Ltd | Construction | 2025 |
| JS London Management Limited | Health & social care | 2018 |
| JSB Central Ltd | Information & communication | 2016 |
| JSC Worldwide Ltd | Information & communication | 2023 |
| JSH Residential Limited | Real estate | 2019 |
| JSK 910 Ltd | Real estate | 2016 |
| Jskc Property Holdings Ltd | Real estate | 2020 |
| Jskipsey Property Ltd | Professional & scientific | 2018 |
| JSL Commercial Limited | Real estate | 2012 |
| JSW (Southern) Ltd | Construction | 2019 |
| JSW Biotech Limited | Professional & scientific | 2021 |
| JT Consultancy Services Ltd | Professional & scientific | 2022 |
| JT Holidays Ltd | Administrative & support | 2025 |
| JTD Construction Ltd | Construction | 2020 |
| JU3TIX.COM Limited | Professional & scientific | 2023 |
| Juguetes EN Madera Export Ltd | Wholesale & retail | 2014 |
| Juice & the Chorus Ltd | Arts & recreation | 2022 |
| JUICE24 Limited | Arts & recreation | 2015 |
| Julian Gayle Limited | Transport & logistics | 2016 |
| Julie WHO Limited | Information & communication | 2016 |
| Julieandrew Ltd | Hospitality | 2013 |
| Julius Kaufmann Limited | Extraterritorial | 1967 |
| Juna Property Ltd | Real estate | 2022 |
| Junari Limited | Information & communication | 2006 |
| Junglist Sauce Limited | Manufacturing | 2025 |
| Juniper Property Management Limited | Households | 2024 |
| Jupiter Chemist Ltd | Wholesale & retail | 2024 |
| Jupiter Parcels LLP | | 2015 |
| Just Baked Ltd | Administrative & support | 2023 |
| Just Fit Kitchen Ltd | Construction | 2023 |
| Just Kosher Ltd | Administrative & support | 2023 |
| Just Lose IT Limited | Education | 2010 |
| Justin Time London Limited | Information & communication | 2016 |
| Jute Trading Ltd | Wholesale & retail | 2005 |
| JV Publicity Ltd | Professional & scientific | 2017 |
| JW Mouldings Limited | Construction | 2015 |
| JWB Solutions Limited | Professional & scientific | 2025 |
| Jwriting Limited | Other services | 2012 |
| JX4 Properties Limited | Real estate | 2020 |
| JYP Limited | Construction | 2018 |
| K & M Property Management Ltd | Real estate | 2014 |
| K & S FOX Properties Limited | Real estate | 2022 |
| K and K Construction-Maintenance Ltd | Other services | 2018 |
| K Gupte Limited | Health & social care | 2008 |
| K J Shukla Property Management Ltd. | Households | 2019 |
| K L Johnson Ltd | Hospitality | 2023 |
| K M B & Associates Limited | Professional & scientific | 2024 |
| K M Derry Brickworks Ltd | Construction | 2003 |
| K P Pabbaraju Ltd | Health & social care | 2015 |
| K Quinn Property Ltd | Real estate | 2023 |
| K Ragudhas Properties Limited | Real estate | 2024 |
| K&K Building Contractors Limited | Construction | 2013 |
| K&M First Group Ltd | Construction | 2014 |
| K&M Management Property Ltd | Real estate | 2025 |
| K&M Medical Services Ltd | Health & social care | 2022 |
| K. a. Wilson Builders Ltd | Construction | 2019 |
| K.A. Exclusive Rides Ltd | Transport & logistics | 2025 |
| K.Likya Ltd | Hospitality | 2016 |
| K.S. Building Services Solihull Limited | Administrative & support | 2011 |
| K9 Consulting Ltd | Other services | 2013 |
| KA Records Limited | Arts & recreation | 2021 |
| KA Suza Ltd | Professional & scientific | 2022 |
| Kadtech Ltd | Administrative & support | 2010 |
| Kadwani Consultants Limited | Health & social care | 2023 |
| Kahlon Building Wholesalers Ltd | Wholesale & retail | 2019 |
| Kai's Cleaning Crew Ltd | Administrative & support | 2024 |
| Kailas Hotel Finance Company Limited | Real estate | 2012 |
| Kailas Hotel Gatwick Gpco Limited | Financial services | 2012 |
| Kailas Hotel Gatwick Incomeco Limited | Real estate | 2012 |
| Kailas Hotel Gatwick Nominee (UK) Ltd | Administrative & support | 2012 |
| Kailas Hotel Heathrow GP (UK) Limited | Real estate | 2012 |
| Kailas Hotel Heathrow Incomeco Limited | Real estate | 2012 |
| Kailas Hotel Heathrow Nominee (UK) Ltd | Administrative & support | 2012 |
| Kajola Limited | Wholesale & retail | 2025 |
| KAL Parmar Productions Private Limited | Arts & recreation | 2011 |
| Kalaron Limited | Information & communication | 2011 |
| Kalmia Ltd | Real estate | 2023 |
| Kalooki Pictures Limited | Information & communication | 2013 |
| Kamino Group Ltd | Information & communication | 2018 |
| Kamino Ltd | Information & communication | 2018 |
| Kanans Sweet House T/A Spice Garden Ltd | Administrative & support | 2016 |
| Kandoo Maintenance Ltd | Construction | 2025 |
| Kantarell Limited | Professional & scientific | 2016 |
| Kanu Nwankwo Heart Foundation | Health & social care | 2000 |
| Kapuas Capital Limited | Real estate | 2016 |
| Karamel Shoes Limited | Wholesale & retail | 2012 |
| Karat Landscape Design & Construction Limited | Administrative & support | 2013 |