| Let’S Clean for YOU Limited | Administrative & support | 2024 |
| Levelup Group Limited | Information & communication | 2009 |
| Lezzet&Co Ltd | Hospitality | 2025 |
| LFB Design Ltd | Information & communication | 2024 |
| Lgam Properties Ltd | Real estate | 2025 |
| LH Logistical Services Ltd | Wholesale & retail | 2025 |
| Lifestyle Blinds Limited | Administrative & support | 2009 |
| Lighthouse IT Strategies Ltd | Information & communication | 2025 |
| Lillyputt Minigolf LLP | | 2022 |
| Lily Louise Properties Limited | Real estate | 2019 |
| Lime Capital Limited | Real estate | 2023 |
| Limit Holdings Ltd | Manufacturing | 2026 |
| Lindblom Design Office Ltd | Professional & scientific | 2023 |
| Link House - BOW Limited | Households | 2001 |
| Linksfield Management Company Limited | Administrative & support | 2000 |
| Little Red Writing Limited | Administrative & support | 2013 |
| Live Financial Planning Ltd | Financial services | 2019 |
| Live Life With Choices Limited | Wholesale & retail | 2008 |
| Ljaudio Limited | Information & communication | 2026 |
| Lkwc Ltd | Professional & scientific | 2017 |
| LL5 Ltd | Wholesale & retail | 2009 |
| LMK 2 Ltd | Transport & logistics | 2024 |
| Loadstore Limited | Professional & scientific | 2022 |
| Local Dialect Limited | Information & communication | 2020 |
| Local Leccy Ltd | Construction | 2013 |
| Loftus & Lane LLP | | 2022 |
| LOI Studio Limited | Information & communication | 2024 |
| Lomax East Films CIC | Information & communication | 2022 |
| London & Hampstead Serviced Offices Limited | Administrative & support | 2011 |
| London Caviar House Limited | Wholesale & retail | 2021 |
| London City CBT Limited | Health & social care | 2021 |
| London Forklift Training Limited | Extraterritorial | 2017 |
| Londonai.Ai Limited | Professional & scientific | 2025 |
| Lone Star Barbeque Ltd | Hospitality | 2026 |
| Longbay Shutters Ltd | Administrative & support | 2019 |
| Lonsdale (Kent) Limited | Real estate | 1961 |
| Lord Byron Inns Ltd | Hospitality | 2021 |
| Lord Byron Limited | Hospitality | 2017 |
| Lost Tide Ltd | Administrative & support | 2016 |
| Louanna Holdings Limited | Financial services | 2010 |
| Louisa Bay Ltd | Hospitality | 2022 |
| Love Erotic Ltd | Wholesale & retail | 2016 |
| Love Lilibets London Ltd | Wholesale & retail | 2025 |
| LR Holdings & Lettings Limited | Hospitality | 2023 |
| LRG Works Limited | Real estate | 2022 |
| Lucern Apartments Management Co. Ltd | Households | 2012 |
| Lucky House Broadstairs Limited | Hospitality | 2021 |
| Luke Edmonds Limited | Extraterritorial | 2013 |
| Luma Climbing Limited | Arts & recreation | 2024 |
| Luxell UK Limited | Wholesale & retail | 2019 |
| LVE (Lettings & Management) Ltd. | Manufacturing | 2014 |
| Lycali Ltd | Public administration | 2022 |
| Lyndenhurst Copperfield Management Limited | Households | 1978 |
| M & J Aesthetics Limited | Health & social care | 2009 |
| M Ashfaque & Co Limited | Wholesale & retail | 2011 |
| M Chomette Studio Limited | Professional & scientific | 2020 |
| M I Jones Limited | Professional & scientific | 2018 |
| M J Stores LLP | | 2009 |
| M R & S a Lambert Properties Ltd | Real estate | 2016 |
| M R Smart Repair Limited | Wholesale & retail | 2016 |
| M T Building Services Limited | Construction | 2015 |
| M.J. Raven & SON Limited | Manufacturing | 1993 |
| Maak Real Estate Investment Ltd | Real estate | 2024 |
| Maak Services Ltd | Information & communication | 2021 |
| MAC Seager Rail Ltd | Construction | 2025 |
| Mach Associates Limited | Information & communication | 1998 |
| Made by Rebecca Ltd | Information & communication | 2020 |
| Madison Entertainment Ltd | Information & communication | 2018 |
| Madlyn Maya Limited | Health & social care | 2023 |
| Magno Clinics Ltd | Health & social care | 2025 |
| Magnolia's (Ramsgate) Ltd | Hospitality | 2023 |
| Magorium Properties Ltd | Real estate | 2022 |
| Mahe Consulting Limited | Professional & scientific | 2013 |
| Mainline Operations Limited | Administrative & support | 2025 |
| Maison Brique Building RTM Company Limited | Households | 2024 |
| Majeseco Limited | Financial services | 2023 |
| Malvi Accountancy Services Limited | Professional & scientific | 2010 |
| MAM Estate Developments Ltd | Construction | 2025 |
| MAN and SON Investments Limited | Real estate | 2009 |
| Manston Golf Centre Limited | Arts & recreation | 2003 |
| Maple Close Residents Co. Ltd | Households | 2017 |
| Marc Pierre's Kitchen Limited | Hospitality | 2019 |
| Marcantonio Limited | Professional & scientific | 2000 |
| Marcella Court RTM Company Limited | Households | 2006 |
| Marchesi Bros. Limited | Real estate | 2017 |
| Margate Investment Group Ltd | Real estate | 2017 |
| Margate Language Centre Limited | Education | 1994 |
| Margate Roofing Ltd | Construction | 2019 |
| Marginalia Media Limited | Other services | 2026 |
| Mark Barry Joinery Limited | Construction | 2014 |
| Maspri Construction Ltd | Construction | 2026 |
| Master Floors Ltd | Wholesale & retail | 2023 |
| Matimati Ltd | Professional & scientific | 2023 |
| Matt and Millies Fish Ltd | Wholesale & retail | 2026 |
| Maver Consultancy Limited | Administrative & support | 2020 |
| MAX Level Consulting Limited | Professional & scientific | 2022 |
| Maxalding Agency Ltd | Professional & scientific | 2026 |
| Maxed-Up Enterprises Limited | Wholesale & retail | 2009 |
| Maxicami Property Ltd | Real estate | 2026 |
| Maxj Capital Limited | Financial services | 2019 |