| JCM Autofleet Limited | Wholesale & retail | 2020 |
| JD & SD Properties Limited | Real estate | 2018 |
| Jeal Properties Limited | Financial services | 2016 |
| JKG Logistics Ltd | Transport & logistics | 2025 |
| JL Hospitality and Events Limited | Hospitality | 2025 |
| JL Quantum Holdings Ltd | Financial services | 2025 |
| JM Music Limited | Information & communication | 2007 |
| JMG Developments Limited | Real estate | 2015 |
| Jmhing Power Limited | Manufacturing | 2016 |
| JN Campaigns Limited | Other services | 2021 |
| JOE Sherratt Chartered Building Services Engineers Ltd | Construction | 2017 |
| John&Chris Ltd | Transport & logistics | 2017 |
| Joinery Classics Limited | Manufacturing | 2004 |
| Jonathan Nash Ltd | Information & communication | 2018 |
| JOS Consulting Services Limited | Other services | 2020 |
| JP Heavy Vehicle Maintenance and Repairs Ltd | Wholesale & retail | 2023 |
| JP Potters Limited | Hospitality | 2024 |
| JPK Design Limited | Professional & scientific | 1993 |
| Jr-Public Relations Ltd | Professional & scientific | 2015 |
| Jsts Fitness Limited | Arts & recreation | 2022 |
| Jusfernow Ltd | Health & social care | 2022 |
| JVS Trading Ltd | Wholesale & retail | 2024 |
| K2 Cooling Services Ltd | Construction | 2023 |
| Kamla Vijay Limited | Real estate | 2019 |
| Keeling Investments Limited | Real estate | 2020 |
| Keeling Limited | Financial services | 2007 |
| Keep Smilin Limited | Administrative & support | 2007 |
| Keilder Solutions Limited | Information & communication | 2007 |
| Kensington Group Limited | Financial services | 2016 |
| Kensington Limited | Real estate | 2016 |
| KEO Heating and Plumbing Limited | Construction | 2018 |
| Kevin Lownds Funeral Services Limited | Other services | 2018 |
| Keynote Mortgage Solutions Limited | Real estate | 2016 |
| Khlb Ltd | Financial services | 2025 |
| King Street Studios CIC | Administrative & support | 2017 |
| Kiran Jewels Collections Limited | Wholesale & retail | 2019 |
| KMF Group Limited | Financial services | 2003 |
| Knutsford Concrete and Aggregates Limited | Administrative & support | 2011 |
| Koka Associates Limited | Professional & scientific | 2024 |
| KP Plan Limited | Other services | 2022 |
| Ktodd Consulting Limited | Professional & scientific | 2015 |
| L & R Contracting Services Ltd | Construction | 2019 |
| L V Garside Limited | Health & social care | 2026 |
| LA Lettings Limited | Real estate | 2012 |
| LA Locksmiths Ltd | Other services | 2023 |
| Lamont Shaylah Limited | Professional & scientific | 2018 |
| Last Gasp Consulting Ltd | Information & communication | 2025 |
| LB Change Project Consultancy Ltd | Information & communication | 2015 |
| LDJ Media Limited | Administrative & support | 2017 |
| Lead to Change CIC | Education | 2011 |
| Leaf Trio Health Ltd | Other services | 2022 |
| Leaf Trio Limited | Professional & scientific | 2015 |
| Leighton & Findler Properties Ltd | Real estate | 2026 |
| Lemaca Limited | Hospitality | 1999 |
| Leven Laboratories Limited | Manufacturing | 2023 |
| Lightfield Properties Limited | Professional & scientific | 2015 |
| LIL FOX Limited | Wholesale & retail | 2019 |
| Limegreen Software Limited | Information & communication | 2013 |
| Links International Limited | Other services | 1992 |
| Liquid Skin Ltd | Information & communication | 2020 |
| Literary Roots Limited | Extraterritorial | 2020 |
| Little Person Ltd | Wholesale & retail | 2021 |
| Live Your Way Ltd | Other services | 2019 |
| LJG Electrical Services Staffs Limited | Construction | 2001 |
| LJR Transport Ltd | Transport & logistics | 2016 |
| LJV Limited | Wholesale & retail | 2017 |
| Loci Limited | Information & communication | 1999 |
| Lockett & Co (Cheadle) Limited | Wholesale & retail | 2022 |
| Logisticae Limited | Transport & logistics | 2019 |
| Longdon Management Services Limited Liability Partnership | | 2011 |
| Longevity Life Ltd | Other services | 2018 |
| Loomer Medical Supplies Limited | Health & social care | 2013 |
| Lords Film Ltd | Information & communication | 2024 |
| Lorna Bailey Ceramics Limited | Manufacturing | 2019 |
| Love Clay Limited | Administrative & support | 2016 |
| Lovett Care (Harrogate) Ltd | Construction | 2019 |
| Lovett Care (ST Helens) Ltd | Construction | 2020 |
| Lovett Care Newark (Opco) Limited | Health & social care | 2026 |
| Lowell and Hunter Limited | Real estate | 2021 |
| LSB Electrical Solutions Limited | Manufacturing | 2022 |
| LUV2LET.COM Limited | Administrative & support | 2009 |
| Luxsol Ltd | Other services | 2023 |
| Lyme Brook Investments Ltd | Real estate | 2025 |
| Lyme Brook Property Limited | Real estate | 2025 |
| Lymebrook Media Limited | Manufacturing | 2008 |
| Lymescape Limited | Real estate | 2008 |
| Lymore Holdings Limited | Financial services | 2023 |
| Lymore Properties Limited | Real estate | 2024 |
| M & M Developments (Stoke) Limited | Extraterritorial | 2005 |
| M & M Investments Holdings Limited | Financial services | 2022 |
| M & M Vehicle Repairs Holdings Limited | Financial services | 2022 |
| M P Joinery & Building Services Limited | Construction | 2014 |
| M Simpson Carriage Cleaning Limited | Administrative & support | 2018 |
| M&A Repairs Limited | Wholesale & retail | 2022 |
| M.P.E. (Staffordshire) Limited | Construction | 1999 |
| Maccas London Ltd | Other services | 2018 |
| Machine Trading International Limited | Wholesale & retail | 2001 |
| Madeley Property Investments Limited | Real estate | 2022 |
| Madhuri Limited | Health & social care | 2018 |
| Magnolio Holdings Limited | Financial services | 2014 |