| Kingfisher Site Solutions Ltd | Professional & scientific | 2018 |
| Kingshall Developments Ltd | Construction | 2026 |
| Kirk & Kirk Consulting Limited | Professional & scientific | 2025 |
| Kirk and Kirk Ltd | Other services | 2019 |
| Kirk and Kirk Services Ltd | Professional & scientific | 2022 |
| Kirsten's Care Ltd | Health & social care | 2019 |
| KIT Pang Ltd | Wholesale & retail | 2026 |
| Kitchens 2 Bathrooms Limited | Wholesale & retail | 2011 |
| Kitsune Colour Limited | Professional & scientific | 2024 |
| KJ Hickman Consulting Limited | Professional & scientific | 2020 |
| KLS Homes Limited | Real estate | 2021 |
| KLS Security Limited | Administrative & support | 2026 |
| Knights Cooling Services Ltd | Construction | 2024 |
| Kovic Creative Limited | Professional & scientific | 2017 |
| Kowalewska Ltd | Wholesale & retail | 2018 |
| KP Esports Limited | Arts & recreation | 2019 |
| KP Heating Sudbury Ltd | Construction | 2024 |
| KR Johnson Ltd | Financial services | 2021 |
| Kraken Debt Collections Limited | Financial services | 2025 |
| Kristy M Chan Ltd | Construction | 2023 |
| Krystal Property Limited | Real estate | 2020 |
| KWR Management LLP | | 2021 |
| L Groundworkers & Landscapers Limited | Construction | 2022 |
| L J Gammer (Stowmarket) Limited | Wholesale & retail | 2003 |
| L&R Pharma Ltd | Wholesale & retail | 2019 |
| L7 Carpentry and Construction Ltd | Manufacturing | 2020 |
| Laaiqah Aulakh Ltd | Wholesale & retail | 2024 |
| Ladybird Lawncare Ltd | Administrative & support | 2002 |
| Laffittes Limited | Professional & scientific | 2019 |
| Lagotto Solutions Limited | Professional & scientific | 2012 |
| Lakeside Property Management (Stowmarket) Limited | Extraterritorial | 2009 |
| LAM Repairs Limited | Manufacturing | 2019 |
| Langham HWB Limited | Health & social care | 2013 |
| Lapalomba Limited | Financial services | 2024 |
| Larkvale Homes (Gaughton) Limited | Construction | 2017 |
| Larkvale Homes Ltd | Construction | 2014 |
| Last LR Ltd | Wholesale & retail | 2010 |
| Lavenham Limited | Construction | 2022 |
| LDS Building Services Limited | Construction | 2003 |
| LEE Parker Orthopaedics Limited | Health & social care | 2015 |
| Let's Design Architecture Limited | Construction | 2021 |
| Letsrent.Rentals Limited | Real estate | 2016 |
| Lewson Construction Limited | Construction | 2019 |
| Lewson Developments Limited | Real estate | 2025 |
| LGL Construction Limited | Construction | 2024 |
| LGL Groundworks Limited | Construction | 2024 |
| LGL Landscaping Limited | Construction | 2024 |
| Liber Holdings Limited | Financial services | 2021 |
| Liber Systems Limited | Information & communication | 2018 |
| Lifebound Limited | Information & communication | 2024 |
| Lifetime Savings Ltd | Administrative & support | 2021 |
| Lighthouse Coaching and Training Limited | Professional & scientific | 2002 |
| Liite Ltd | Wholesale & retail | 2019 |
| Lillypad Estate Agents Ltd | Real estate | 2023 |
| Lime Green Limited | Professional & scientific | 2007 |
| Limited Time Remaining Limited | Wholesale & retail | 2023 |
| Lind Films Limited | Information & communication | 2023 |
| Linetech Installations Limited | Construction | 2009 |
| Lingwood Food Services Limited | Manufacturing | 1996 |
| Lingwood Holdings 2011 Limited | Professional & scientific | 2011 |
| Linkprop Residential Ltd | Real estate | 2026 |
| Linton Capital Holdings Limited | Professional & scientific | 2024 |
| Lisley Properties Limited | Real estate | 2022 |
| Little PIG Bakery Limited | Manufacturing | 2020 |
| LIV3D Media Limited | Professional & scientific | 2013 |
| Living Fermented Probiotic Foods Ltd | Manufacturing | 2017 |
| LIZ Callaghan Limited | Information & communication | 2021 |
| Lmbee Limited | Construction | 2017 |
| LNC K9 Security Ltd | Administrative & support | 2022 |
| Lndn Made Ltd | Other services | 2016 |
| Lockexpo Ltd | Administrative & support | 2021 |
| Logistics Fleet Management Support Limited | Professional & scientific | 2020 |
| London Brand Consulting Limited | Professional & scientific | 2009 |
| Longfield Risk Solutions Ltd | Financial services | 2017 |
| Longfields Cafe Ltd | Hospitality | 2025 |
| Longfields Circle Ltd | Professional & scientific | 2024 |
| Lonstrada Ltd | Professional & scientific | 2019 |
| Loop and Lift CIC | Manufacturing | 2025 |
| Louisebcomms Ltd | Professional & scientific | 2020 |
| LRS Group Management Ltd | Professional & scientific | 2019 |
| Ls&T Parks Holdings Limited | Financial services | 2022 |
| LTW Finance Ltd | Financial services | 2020 |
| Lucas Legal Costs Limited | Professional & scientific | 2009 |
| Lucas Palmer Physiotherapy Limited | Health & social care | 2012 |
| Lucas's Company TM Ltd | Construction | 2025 |
| Luna Lettings Limited | Real estate | 2019 |
| Luxemotors Valeting & Detailing Ltd | Wholesale & retail | 2025 |
| LVS Decorative Arts Limited | Wholesale & retail | 2013 |
| LWB Global Ltd | Wholesale & retail | 2025 |
| Lybos Ltd | Information & communication | 2018 |
| Lynch Safety Services Ltd | Administrative & support | 2022 |
| Lynne Clayton Limited | Hospitality | 2005 |
| M & B Marketing Limited | Arts & recreation | 2021 |
| M & L Kitchen Limited | Wholesale & retail | 2024 |
| M CUT Barber Ltd | Other services | 2020 |
| M E Bryan Ltd | Professional & scientific | 1994 |
| M E Ruffles Electrical Contractors Limited | Construction | 2020 |
| M P Building Solutions Limited | Construction | 2009 |
| M&Cv Ltd | Construction | 2025 |
| M&L Hair Design Ltd | Other services | 2014 |