| Hantig Investment Properties Limited | Real estate | 2019 |
| Harmonia House Ltd | Health & social care | 2023 |
| Harolds Head Limited | Hospitality | 2014 |
| Harry Scaffolding Ltd | Construction | 2020 |
| Hatton Garden Vault London Limited | Other services | 2017 |
| Hayden James International Limited | Administrative & support | 2010 |
| Helios Homes Investment Properties Limited | Real estate | 2026 |
| Hersh's Logistics Limited | Professional & scientific | 2021 |
| High Oak Developments Ltd | Construction | 2007 |
| HIP Sonic Music Ltd | Arts & recreation | 2019 |
| Holm Front Properties Ltd | Real estate | 2019 |
| Honey Estates Management Limited | Real estate | 2024 |
| House Keys Ltd | Households | 2023 |
| I.Israel,Limited | Financial services | 1923 |
| Ice Cream Records Limited | Arts & recreation | 2000 |
| IN Depth Solutions Limited | Other services | 2016 |
| Inhealth Associates Ltd | Professional & scientific | 2014 |
| Invexus Financial Group Limited | Financial services | 2013 |
| Iron MAN Washing Limited | Other services | 2022 |
| ITS My Health Limited | Arts & recreation | 2024 |
| J K Media Design Limited | Information & communication | 2008 |
| J L T Construction Ltd | Construction | 2017 |
| J Stern Holdings Ltd | Financial services | 2026 |
| J.Oc Management Ltd | Professional & scientific | 2023 |
| Jack BOW Lane Ltd | Other services | 2023 |
| Jack Mayfair Ltd | Other services | 2023 |
| Jack Shoreditch Ltd | Other services | 2023 |
| Jagu Property Ltd. | Real estate | 2019 |
| Jala Property Ltd | Real estate | 2025 |
| Jane Norman Limited | Other services | 2025 |
| Jayzee Properties Ltd | Real estate | 2022 |
| Jdcg Properties Ltd | Real estate | 2024 |
| JFF Consulting Limited | Administrative & support | 2024 |
| Jfml Properties Limited | Real estate | 2015 |
| JLD Waste Ltd | Water & waste | 2023 |
| Johnny Flowers Ltd | Wholesale & retail | 2021 |
| JTC Holdings Ltd | Administrative & support | 2016 |
| Karuna Care Limited | Health & social care | 2014 |
| KBK Property Limited | Real estate | 2021 |
| KCK Construction Limited | Construction | 2023 |
| Kinezo's Ltd | Hospitality | 2024 |
| Kipelas Ltd | Financial services | 2025 |
| Koala Build & Maintain Ltd | Construction | 2025 |
| Kontos Design Services Ltd | Professional & scientific | 2024 |
| Kpmj Properties Limited | Real estate | 2015 |
| Kurt & Son's Waste OIL Recycled Ltd | Water & waste | 2023 |
| Kyls Construction Ltd | Construction | 2024 |
| Kyman Innovations Ltd | Wholesale & retail | 2025 |
| L J Collins Legal Limited | Professional & scientific | 2023 |
| Lanson Sinclair Ltd | Education | 2021 |
| Lawnscience East Herts Limited | Administrative & support | 2024 |
| LC Valeting Ltd | Administrative & support | 2023 |
| Learnfull Ltd | Education | 2021 |
| Leyton Property Developments Ltd | Construction | 2015 |
| Liberation Live Ltd | Professional & scientific | 2021 |
| Liberation Spark Limited | Financial services | 2020 |
| Liondaris & Co Limited | Professional & scientific | 2024 |
| Liondaris Commercial Limited | Real estate | 2021 |
| Liondaris Developments Ltd | Construction | 2020 |
| Liondaris Limited | Real estate | 2019 |
| Liondaris Trading Limited | Real estate | 2012 |
| Lisa Sheerin Ltd | Administrative & support | 2025 |
| LMO Finance Limited | Financial services | 2024 |
| Lnmm Holdings Ltd | Financial services | 2026 |
| Locon Lettings Ltd | Real estate | 2010 |
| Loft LDN Limited | Other services | 2017 |
| London Dandy Ltd | Manufacturing | 2025 |
| London Jewellery Club Ltd | Manufacturing | 2021 |
| London Lets (UK) Limited | Real estate | 2014 |
| London Machinery Rentals Limited | Other services | 2009 |
| Lord Green Energy Ltd | Construction | 2026 |
| Lotus Horizon Limited | Professional & scientific | 2025 |
| Love Your Doorstep Community CIC | Information & communication | 2019 |
| Love Your Doorstep Limited | Professional & scientific | 2012 |
| LS Plumbing & Heating (London) Limited | Construction | 2024 |
| LS Plumbing & Heating Limited | Construction | 2023 |
| LTS Climate Ltd | Energy | 2025 |
| Lumina Labs Ltd | Information & communication | 2026 |
| Lynxtech Limited | Construction | 2019 |
| Lyra Trading Limited | Other services | 2014 |
| M & O Investments Limited | Real estate | 2012 |
| M.A.L Mechanical Limited | Construction | 2024 |
| Mandarin Build Ltd | Construction | 2022 |
| Manforte Limited | Other services | 2015 |
| Market Car Service Limited | Other services | 2006 |
| Mascoo Properties Ltd | Other services | 2017 |
| Master Gardens Limited | Administrative & support | 2019 |
| Masterpiece Jewellers Limited | Wholesale & retail | 2016 |
| MC Media Limited | Arts & recreation | 2007 |
| MD7 Limited | Other services | 2015 |
| Megasoft Digital Limited | Information & communication | 2014 |
| Mellarose Ltd | Other services | 2018 |
| MEM Management Ltd | Administrative & support | 2024 |
| Memduh Properties Ltd | Real estate | 2020 |
| Meoni Ltd | Real estate | 2021 |
| MG Construction Consultancy Limited | Professional & scientific | 2024 |
| MGK Solutions Limited | Other services | 2012 |
| MGM Worktops Limited | Construction | 2022 |
| Mgma Solutions Limited | Information & communication | 2013 |
| Michael Omiros Limited | Professional & scientific | 2012 |