| Kind Hands Care Ltd | Health & social care | 2022 |
| Kingfisher SE Associates Ltd | Professional & scientific | 2023 |
| Kingsbury C&P Ltd | Administrative & support | 2015 |
| Kingshipp Ltd | Professional & scientific | 2018 |
| Kinsella Music Ltd | Information & communication | 2023 |
| KJS Carpentry Contractors Limited | Manufacturing | 2023 |
| Klgamingcoach CYF | Professional & scientific | 2025 |
| Knect Assemblies Limited | Manufacturing | 2009 |
| Knect Limited | Manufacturing | 2009 |
| KO Plumbing Heating Ltd | Construction | 2021 |
| Koda UK (Kreative Original Design Academy) CYF. | Professional & scientific | 2023 |
| KPD Homes Limited | Real estate | 2019 |
| KPX Entertainment Technology Limited | Information & communication | 2013 |
| KT Leisure Limited | Hospitality | 2019 |
| L&A Coffi Ltd | Hospitality | 2023 |
| L&J Anderson Ltd | Real estate | 2025 |
| L&L Specialist Services Ltd | Professional & scientific | 2025 |
| Labduck Limited | Wholesale & retail | 2024 |
| Lake Hotels Ltd | Hospitality | 2021 |
| Lamro Ltd | Real estate | 2020 |
| Landeg Lettings Limited | Real estate | 2025 |
| Langtons Farm CYF | Agriculture & fishing | 2019 |
| Lansbury Yard Ltd | Hospitality | 2026 |
| Lansdowne Compliance Consultancy Ltd | Professional & scientific | 2011 |
| Lawrence and Harris Limited | Health & social care | 2006 |
| Layza Ltd | Professional & scientific | 2025 |
| Lazy River Limited | Professional & scientific | 2017 |
| LC Automotive Engineering Ltd | Wholesale & retail | 2021 |
| LC Fire & Security Ltd | Administrative & support | 2023 |
| Leanne Kent Property Ltd | Real estate | 2022 |
| Leather Collection Ltd | Wholesale & retail | 2025 |
| LED Property Investments Ltd | Real estate | 2025 |
| Leigh & Co. Consultancy Ltd | Real estate | 2020 |
| Lenstec Optical Group Limited | Manufacturing | 2012 |
| Lesley Catherine Muggeridge Ltd | Extraterritorial | 2025 |
| Letting Essentials Limited | Professional & scientific | 2018 |
| Levan Ecology Ltd | Professional & scientific | 2013 |
| Lewis & Darkes Ltd | Real estate | 2021 |
| LEX2 Limited | Real estate | 2025 |
| LF3 Holdings Limited | Financial services | 2026 |
| LFB Contractors Ltd | Construction | 2025 |
| LG Dylunio Limited | Professional & scientific | 2020 |
| Liberating AI Limited | Information & communication | 2025 |
| Liberty Workwear Limited | Wholesale & retail | 1999 |
| Lift Club Ltd | Administrative & support | 2023 |
| Lilyalex Construction Ltd | Construction | 2019 |
| Lilyalex Leasing Ltd | Real estate | 2019 |
| Lilyalex Properties Ltd | Real estate | 2015 |
| Lilyaylarosie Cornwall Ltd | Real estate | 2017 |
| Lilycarol Ltd | Real estate | 2017 |
| Lilyjasper.Org | Other services | 2024 |
| Lime Tree Holdings Ltd | Real estate | 2021 |
| Limitless Portfolios Ltd | Other services | 2024 |
| Lintons Home Ltd | Wholesale & retail | 2018 |
| Lisburn Court Management Committee Limited | Real estate | 2018 |
| LIT Fires Ltd | Administrative & support | 2021 |
| Litework Electrical Ltd | Construction | 2024 |
| Litigation & Research Services Limited | Administrative & support | 2015 |
| Little Rascals Rugby Ltd | Health & social care | 2025 |
| Live Well Vets Ltd | Professional & scientific | 2019 |
| Llancaiach Fawr Manor House Ltd | Hospitality | 2025 |
| Lloyds Properties & Rentals Ltd | Real estate | 2024 |
| Lmspps Ltd | Professional & scientific | 2022 |
| Lmunite Ltd | Administrative & support | 2017 |
| LNB Investments Limited | Real estate | 2021 |
| Logic Freight Ltd | Transport & logistics | 2006 |
| Look Fresh Building, Painting and Cleaning Services Limited | Construction | 2023 |
| Loose Ends SW Limited | Other services | 2026 |
| Lords International Limited | Manufacturing | 1994 |
| Loren James Group Limited | Arts & recreation | 2022 |
| Lostandfoundgolfballs Ltd | Wholesale & retail | 2024 |
| Love Leds Ltd | Wholesale & retail | 2018 |
| Loving Earth Limited | Manufacturing | 2026 |
| Lowd Holdings Ltd | Financial services | 2025 |
| Lowrie&Co Ltd | Hospitality | 2024 |
| LPJ Property Management Limited | Construction | 2024 |
| LPJ Property Revive Ltd | Construction | 2026 |
| LR Hair Design Ltd | Other services | 2025 |
| LST Property Group Ltd | Real estate | 2025 |
| LTH Threads Ltd | Wholesale & retail | 2025 |
| Luca Moore CYF | Hospitality | 2025 |
| Lucid BLU' Ltd | Construction | 2018 |
| Luke Humphreys Plumbing & Heating Ltd | Construction | 2024 |
| Luma Property Solutions Ltd | Real estate | 2020 |
| Luxury Fabulous Scents Ltd | Manufacturing | 2023 |
| Lydand Properties Ltd | Real estate | 2024 |
| LYN Bowkett Financial Planning Limited | Financial services | 2020 |
| Lynch Healthcare Limited | Administrative & support | 2009 |
| Lynton Industry Investments Ltd | Real estate | 2025 |
| Lyons Law Ltd | Professional & scientific | 2014 |
| Lysh Ltd | Information & communication | 2019 |
| M & a Accountancy Limited | Professional & scientific | 1996 |
| M & M Concrete Reinforcement Ltd | Construction | 2018 |
| M a & L Properties Ltd | Real estate | 2022 |
| M D Wilson Electrical Services Ltd | Construction | 2015 |
| M H Jones Landscape and Maintenance Limited | Administrative & support | 2002 |
| M Jones Road Haulage Ltd | Transport & logistics | 2006 |
| M Pope Building Services Limited | Construction | 2007 |
| M&H Formwork Ltd | Construction | 2025 |
| M3 Self Storage Ltd | Other services | 2021 |