| JPM Racing Limited | Transport & logistics | 2022 |
| JPP Retail Ltd | Wholesale & retail | 2022 |
| JPW Taxis Ltd | Wholesale & retail | 2011 |
| JRA 1 Limited | Hospitality | 2023 |
| JRA Electrical Ltd | Construction | 2026 |
| Jras (Harrogate) Ltd | Professional & scientific | 2002 |
| Jrkr Properties Ltd | Real estate | 2025 |
| Jrmillinery Ltd | Manufacturing | 2024 |
| JRS Building Limited | Construction | 2006 |
| JS Automotive Specialist Ltd | Wholesale & retail | 2022 |
| JS Commercial Properties Limited | Real estate | 2015 |
| JS Holdings Limited | Financial services | 2020 |
| Jschu Limited | Professional & scientific | 2014 |
| JSH Consulting Limited | Professional & scientific | 2024 |
| JSK Builders Ltd | Construction | 2011 |
| Jtap Media Ltd | Information & communication | 2014 |
| Jtmr Limited | Wholesale & retail | 2013 |
| Jtpcc Ltd | Professional & scientific | 2025 |
| JTS Cycles Ltd | Wholesale & retail | 2017 |
| Jtso Limited | Health & social care | 2014 |
| Jubibi Ltd | Professional & scientific | 2024 |
| Jubilee Copy Ltd | Extraterritorial | 2020 |
| Judgeservice Research Ltd | Professional & scientific | 2011 |
| Judith Kelbie LLP | | 2009 |
| Juice & Friends Ltd | Wholesale & retail | 2019 |
| Juicy Ltd | Extraterritorial | 2012 |
| Juillet Limited | Extraterritorial | 2020 |
| JUL1A Limited | Extraterritorial | 2020 |
| JUL1AN Limited | Extraterritorial | 2020 |
| JUL1E Limited | Extraterritorial | 2020 |
| Julian Harforth Ltd | Other services | 2020 |
| Julian Stocks Limited | Arts & recreation | 2003 |
| Julius Limited | Extraterritorial | 2020 |
| Juniper Tree Therapy Limited | Health & social care | 2018 |
| Just a Day Limited | Professional & scientific | 2023 |
| Just B Bereavement and Mental Health Support | Health & social care | 2023 |
| Just Fused Ltd | Hospitality | 2019 |
| Just James Limited | Administrative & support | 2024 |
| Just Wright Research Ltd | Professional & scientific | 2021 |
| JUST1CE Limited | Extraterritorial | 2020 |
| JUST1NE Limited | Extraterritorial | 2020 |
| Justin Associates Limited | Financial services | 2007 |
| Justin March Consultancy Limited | Information & communication | 2013 |
| Justin Trusscott Limited | Extraterritorial | 2019 |
| JW Partners Limited | Administrative & support | 2013 |
| JW Steel Design UK Ltd | Professional & scientific | 2019 |
| JWH Wealth Management Ltd | Financial services | 2007 |
| JWI Builders Limited | Construction | 2012 |
| JWK Developments (SPV 1) Ltd | Construction | 2021 |
| JWK Developments (SPV 2) Ltd | Construction | 2022 |
| JWK Developments (SPV3) Ltd | Construction | 2024 |
| JWK Developments Ltd | Construction | 2019 |
| JWP Properties (Yorkshire) Ltd | Real estate | 2024 |
| Jyam Devlopment Ltd | Information & communication | 2021 |
| K & M Lettings Limited | Real estate | 2015 |
| K & M Peel Limited | Administrative & support | 2021 |
| K Bland Joinery Ltd | Construction | 2015 |
| K E Powell Ltd | Health & social care | 2015 |
| K E Seed Building Contractors Limited | Construction | 2003 |
| K P Garside Building and Joinery Limited | Construction | 2003 |
| K S R Installations Limited | Construction | 2006 |
| K Simpson & Sons Limited | Agriculture & fishing | 2012 |
| K. B. Surveys Limited | Construction | 2014 |
| K.M. Design Engineering Limited | Construction | 1998 |
| K.R.M.C. (Harrogate) Limited | Households | 1985 |
| K1M Ltd | Extraterritorial | 2020 |
| K1MBERLY Ltd | Extraterritorial | 2020 |
| K1RA Limited | Extraterritorial | 2020 |
| K1TTY Limited | Extraterritorial | 2026 |
| K2 Recycle Ltd | Manufacturing | 2022 |
| K9 Properties Limited | Real estate | 2019 |
| KAB1R Limited | Wholesale & retail | 2022 |
| Kaerus Consulting Ltd | Professional & scientific | 2010 |
| KAF Accounts Limited | Professional & scientific | 2026 |
| Kahn FM Limited | Extraterritorial | 2015 |
| Kairos Global Holdings Ltd | Financial services | 2025 |
| Kairos Network Church | Other services | 2011 |
| Kalisz Renovations & Solutions Ltd | Construction | 2025 |
| KAM Offshore Services Limited | Professional & scientific | 2018 |
| Kammy Medical Services Ltd | Wholesale & retail | 2025 |
| Kando PM Ltd | Professional & scientific | 2008 |
| Kantan Consulting Limited | Professional & scientific | 2018 |
| Kape Agency Limited | Wholesale & retail | 2022 |
| Kariba Creative Media Ltd | Information & communication | 2005 |
| Karim FM Limited | Extraterritorial | 2020 |
| Karl Chapman Ltd | Professional & scientific | 2014 |
| Karl Hanover Properties Limited | Real estate | 2016 |
| Karl Rahmani Ltd | Financial services | 2023 |
| Karma Co Vintage Limited | Wholesale & retail | 2023 |
| Kashif for Trade Ltd | Wholesale & retail | 2024 |
| Kate Bancroft Limited | Other services | 2024 |
| Kath Lancaster Nursing Consultancy Limited | Professional & scientific | 2008 |
| Katie's Classroom Ltd | Education | 2014 |
| Katz Ltd | Real estate | 2023 |
| Kawa House Limited | Hospitality | 2025 |
| Kaweco Pens Ltd | Wholesale & retail | 2010 |
| KAY Building and Project Consultancy Limited | Professional & scientific | 2024 |
| Kayceeng Ltd | Administrative & support | 2019 |
| KB Anaesthesia Ltd | Health & social care | 2023 |
| KB Consult Ltd | Professional & scientific | 2021 |