| JM Foods Limited | Hospitality | 2015 |
| Jmcg IT Service Analysis Ltd | Administrative & support | 2015 |
| JMG Electrical Engineering Ltd | Construction | 2017 |
| JMG Electrical Ltd | Construction | 2004 |
| JMG Installations Ltd | Construction | 1989 |
| JMW Trading Ltd | Wholesale & retail | 2018 |
| JMY Enterprises Limited | Professional & scientific | 2006 |
| JNL Residential Ltd | Real estate | 2025 |
| Joanne Boyle Creative Ltd | Professional & scientific | 2026 |
| Jody Newell Limited | Administrative & support | 2014 |
| Joes Transport Ltd | Transport & logistics | 2017 |
| JOH Consultancy LLP | | 2011 |
| John Alex Ltd | Professional & scientific | 2021 |
| John Goodridge Limited | Wholesale & retail | 1960 |
| John Young Creative Industries Ltd | Arts & recreation | 2015 |
| Johnston Dentistry Limited | Health & social care | 2025 |
| Joint Reaction LLP | | 2013 |
| Joint Trade & Property Group Company Limited | Real estate | 2019 |
| Jonathan Spruce Limited | Construction | 2011 |
| Jonathan Steffen Limited | Professional & scientific | 2012 |
| Jones Brothers Holdings Limited | Real estate | 2023 |
| Jones Property Estates Limited | Real estate | 2017 |
| Jones, Powell and Associates Ltd | Professional & scientific | 2012 |
| Jopfre Ltd | Information & communication | 2019 |
| Jordan Consulting Limited | Information & communication | 2010 |
| Joseph Berry Interiors Limited | Wholesale & retail | 2019 |
| Joslin DYE Ltd | Agriculture & fishing | 2021 |
| Joules Law Limited | Professional & scientific | 2014 |
| Joy of OUD Limited | Wholesale & retail | 2023 |
| JR Hatches Field Limited | Real estate | 2024 |
| JR Space Ltd | Real estate | 2002 |
| JR2DM Ltd | Financial services | 2025 |
| JRB Building Ltd | Construction | 2003 |
| JRJ Golf Limited | Wholesale & retail | 2022 |
| JRR Property Investment Limited | Real estate | 2020 |
| JS Penny Ltd | Professional & scientific | 2019 |
| JSK Associates Limited | Professional & scientific | 2011 |
| JT Art Asset Limited | Wholesale & retail | 2017 |
| Jubilee Church Farnham | Other services | 2010 |
| Judith Bealey Associates Limited | Professional & scientific | 2008 |
| Judy Lane ICS Limited | Administrative & support | 2016 |
| Julian Chiropractic Limited | Health & social care | 2011 |
| Jumi Ltd | Information & communication | 2026 |
| Just Claims Limited | Financial services | 2021 |
| Just Knott Ltd | Other services | 2025 |
| Just Niche Limited | Administrative & support | 2015 |
| Just the Right Temperature Ltd | Construction | 2023 |
| JV Asset Investments Ltd | Real estate | 2022 |
| Jvmunday's Ltd | Professional & scientific | 2013 |
| JW Property Law Ltd | Professional & scientific | 2024 |
| JWC Commercial Consultancy Ltd | Information & communication | 2023 |
| JWL Finance Ltd | Financial services | 2019 |
| JWP Heating and Plumbing Limited | Construction | 2023 |
| JZ Group Ltd | Construction | 2017 |
| K & D Complete Services Limited | Administrative & support | 2012 |
| K C Gillett General Builders Limited | Construction | 2003 |
| K D Direct Limited | Manufacturing | 2017 |
| K Gillett Properties Limited | Real estate | 2024 |
| K&Hr Ltd | Information & communication | 2019 |
| Kahli Lewis Dance Company LLP | | 2024 |
| Kaizen Meraki Ltd | Information & communication | 2021 |
| Kaizen Partners Limited | Professional & scientific | 2008 |
| Kalag Limited | Real estate | 2024 |
| Kalahari Biltong Ltd | Hospitality | 2018 |
| Kaleidoscope Minds Ltd | Education | 2025 |
| KAM Traffic Engineering Ltd | Professional & scientific | 2012 |
| Kan-Nrg Ltd | Manufacturing | 2024 |
| Kapasun Ltd | Education | 2011 |
| Kariwak Consulting Ltd | Information & communication | 2013 |
| Karkade Drinks Limited | Manufacturing | 2017 |
| KAS ALI Consultancy Limited | Professional & scientific | 2026 |
| Kaskr Ltd | Information & communication | 2026 |
| Kastle 2021 Limited | Wholesale & retail | 2021 |
| Kate Stoddart Limited | Professional & scientific | 2010 |
| Kathglade Limited | Manufacturing | 1976 |
| Kathryn Virji Limited | Administrative & support | 2012 |
| Kathy Charles (Avondale) Ltd | Arts & recreation | 2013 |
| Kathy Duckett - Love IS in the Hair Ltd | Other services | 2022 |
| Katie O'Hare Consultancy Limited | Education | 2017 |
| Kaula Associates Ltd | Other services | 2017 |
| Kaytey Cowan Consulting Ltd | Information & communication | 2018 |
| Kbaxter Limited | Real estate | 2025 |
| KCD Resources Limited | Professional & scientific | 2009 |
| Kddl Investment Limited | Real estate | 2018 |
| Kduk Limited | Wholesale & retail | 2012 |
| Keenforth Treasury Solutions Limited | Professional & scientific | 2018 |
| Keenglen Care Homes Limited | Health & social care | 2011 |
| Keens Cottages Limited | Households | 2013 |
| Keep Evolving Limited | Administrative & support | 2014 |
| Keep House Property Management Limited | Households | 2019 |
| Keir Hall Training Services Limited | Education | 2011 |
| Keith Knowles Accountants Limited | Professional & scientific | 1998 |
| Keito Systems Limited | Information & communication | 2000 |
| Keleca Ltd | Administrative & support | 2023 |
| Kelpie Productions Limited | Information & communication | 1998 |
| Kelsing Investments Limited | Real estate | 2018 |
| Kenny Recruitment Ltd | Administrative & support | 2018 |
| Kensington and Mayfair Property Management Limited | Households | 2021 |
| Kent ENT Partnership Limited | Health & social care | 2021 |
| Kentallen Limited | Professional & scientific | 2017 |