| JT People Solutions Limited | Professional & scientific | 2025 |
| Jubilee 1950 Limited | Extraterritorial | 2013 |
| Junction 28 Remaps Limited | Wholesale & retail | 2017 |
| Just School Wear (Retail) Limited | Wholesale & retail | 2020 |
| JWH Reform Limited | Construction | 2018 |
| K & L Private Practice Solutions Limited | Other services | 2025 |
| K and J Badrinath Limited | Health & social care | 2016 |
| K D Kirk Limited | Construction | 2026 |
| Kabhal Ltd | Professional & scientific | 2020 |
| Kalaimagal & Nila Ltd | Financial services | 2026 |
| Kamz Properties Ltd | Real estate | 2025 |
| Karmad Limited | Health & social care | 2015 |
| Karos Adventure Limited | Education | 2016 |
| Kasa Viva Limited | Transport & logistics | 2014 |
| Katie Gilbourne Limited | Information & communication | 2019 |
| Kaztech Electrical Limited | Construction | 2021 |
| KC Heat Source Limited | Other services | 2023 |
| Kcjj Ltd | Administrative & support | 2024 |
| KDA Darts Ltd | Education | 2025 |
| KDK Developments Limited | Real estate | 2017 |
| KDT Joinery Ltd | Construction | 2018 |
| Kedarnath OFF Licence Ltd | Wholesale & retail | 2020 |
| Keelo Rooms Ltd | Real estate | 2024 |
| KEH Holdings Limited | Financial services | 2018 |
| KEL House Resources Ltd | Wholesale & retail | 2024 |
| Key Mortgages Lincoln Limited | Professional & scientific | 2022 |
| Keypointliving Ltd | Real estate | 2025 |
| Keyprog Software Solutions Ltd | Information & communication | 2009 |
| KH Interiors Ltd | Professional & scientific | 2026 |
| KH UK Consultancy Ltd | Professional & scientific | 2023 |
| Kickstart Commercial Ltd | Real estate | 2015 |
| Kineticars Ltd | Manufacturing | 2020 |
| Kingdoms Group Ltd | Real estate | 2011 |
| Kirk's Carpets & Wood Floors Fitting Services Ltd | Construction | 2025 |
| Kirk's Carpets & Wood Floors Ltd | Wholesale & retail | 2025 |
| Kisa Group Holdings Ltd | Financial services | 2026 |
| Kj's Automotive Sales Limited | Wholesale & retail | 2026 |
| KJC Properties Mansfield Ltd | Real estate | 2024 |
| KMG Workspace Ltd | Construction | 2025 |
| Knotts Joinery Ltd | Construction | 2023 |
| KP Bar & Restaurant Limited | Hospitality | 2024 |
| Kppconstruction Ltd | Construction | 2026 |
| Kpplumber Ltd | Construction | 2025 |
| Kristian & Gabrielle Ltd | Administrative & support | 2024 |
| Krisyv Ltd | Health & social care | 2025 |
| Ksok Holdings Limited | Financial services | 2024 |
| Kule 1 Ltd | Hospitality | 2026 |
| KVG Holdings Limited | Real estate | 2024 |
| Kwila Ltd | Wholesale & retail | 2023 |
| L&G Holdings (Midlands) Limited | Financial services | 2026 |
| L&G Rail Ltd | Agriculture & fishing | 2022 |
| LA Referrals Limited | Administrative & support | 2023 |
| LA VIE EST Belle Ltd | Other services | 2017 |
| Ladco Ltd | Professional & scientific | 2026 |
| Langan Electrical Limited | Construction | 2015 |
| Langton Construction Limited | Construction | 2018 |
| Lansbrook Limited | Professional & scientific | 1994 |
| Lark Developments Limited | Construction | 2025 |
| Laser Tech 22 Limited | Manufacturing | 2017 |
| Laur Track Ltd | Construction | 2024 |
| LBC Plant Hire Limited | Construction | 2017 |
| LCG Entertainment Ltd | Wholesale & retail | 2023 |
| LCG Ventures Ltd | Wholesale & retail | 2017 |
| LDB Investments Limited | Real estate | 2025 |
| LE Marga Resort Ltd | Wholesale & retail | 2024 |
| Lead Transport Limited | Transport & logistics | 2021 |
| Leam Barber Ltd | Other services | 2025 |
| LEE Marsh Ltd | Administrative & support | 2008 |
| LEE Parapets Services Limited | Construction | 2016 |
| Leivars Investments Ltd | Financial services | 2026 |
| Let's ALL EAT C.I.C. | Hospitality | 2015 |
| Let's Talk Water Ltd | Professional & scientific | 2025 |
| Letts Move Notts Ltd | Real estate | 2012 |
| Lewis Serv Heating Ltd | Construction | 2021 |
| LEY Pizza Ltd | Hospitality | 2026 |
| Lightning Leivars Limited | Arts & recreation | 2022 |
| Lilia & Bailey Design Limited | Manufacturing | 2023 |
| Limes Cafe Limited | Hospitality | 2021 |
| Limes Group Holdings Ltd | Financial services | 2023 |
| Limes Group Properties Ltd | Real estate | 2023 |
| Lindacareyendoltd Ltd. | Health & social care | 2022 |
| Linwood Raker Limited | Manufacturing | 2017 |
| Listing Creations Ltd | Wholesale & retail | 2018 |
| Litchfield Mortgages Limited | Financial services | 2023 |
| Little Violet's Nursery School Ltd | Education | 2024 |
| Living Water Property Services Ltd | Construction | 2019 |
| LJ Foster Limited | Real estate | 2022 |
| LJ Luxury Limited | Other services | 2021 |
| LK Properties & GAS Limited | Real estate | 2025 |
| Local and Community Pubs Limited | Hospitality | 2017 |
| Localhire UK Ltd | Information & communication | 2026 |
| Lock-Down Fire Compartmentation Ltd | Administrative & support | 2019 |
| Lone Wolf Signs and Digital Solutions Limited | Other services | 2024 |
| Longbow Civil Engineering Limited | Construction | 2017 |
| Longbow Civils (Midlands) Limited | Construction | 2017 |
| Lord Property 1 Ltd | Real estate | 2025 |
| Lottie Makes Ltd | Wholesale & retail | 2026 |
| LOW Moor Engineering Company Limited | Real estate | 1970 |
| Lucian Couriers Ltd | Transport & logistics | 2020 |
| Luigiano Construction Limited | Construction | 2024 |