| Kernos Centre | Health & social care | 2002 |
| Keyholder Mortgages Ltd | Financial services | 2021 |
| Keyware Industrial Supplies Ltd | Wholesale & retail | 1996 |
| Kezfil Limited | Extraterritorial | 2007 |
| KHA Design Ltd | Professional & scientific | 2015 |
| KHA Surveyors Ltd | Professional & scientific | 2022 |
| KIA Kaha Investments Ltd | Real estate | 2025 |
| KIM Logan Limited | Information & communication | 2016 |
| King Stanley Group Ltd | Financial services | 2021 |
| King Stanley Properties Ltd | Real estate | 2025 |
| King Stanley Ventures Ltd | Real estate | 2022 |
| Kintail Consulting Ltd | Extraterritorial | 2013 |
| Kirkham Sheidow Limited | Professional & scientific | 2003 |
| Kkroshee & Co Limited | Hospitality | 2025 |
| Klimowicz & Sons Limited | Construction | 2005 |
| KMT Advisory Ltd | Professional & scientific | 2026 |
| Knightbridge Tax Ltd | Professional & scientific | 2024 |
| KNT Publishing T/A Total Tattoo Ltd | Manufacturing | 2019 |
| Konings Juices & Drinks UK Limited | Manufacturing | 2016 |
| Kreative Freedom Ltd | Professional & scientific | 2023 |
| Krewet Ltd | Professional & scientific | 2014 |
| Krwalker Limited | Professional & scientific | 2019 |
| Kseeley Ltd | Manufacturing | 2026 |
| Kurri Ltd | Information & communication | 2025 |
| L & C Skips | | 1993 |
| L and E Portfolio Ltd | Real estate | 2009 |
| L and M Developments Suffolk Ltd | Construction | 2026 |
| L B Contracts Limited | Wholesale & retail | 2015 |
| L Martin Limited | Professional & scientific | 2010 |
| L V Carpentry & Construction Limited | Construction | 2024 |
| LA Luna Creations Ltd | Manufacturing | 2023 |
| Labx Media Group Europe Ltd | Information & communication | 2016 |
| Ladies With a Van Ltd | Water & waste | 2025 |
| Lafrenk Ltd | Wholesale & retail | 2023 |
| Lakesbond Ltd | Households | 2022 |
| Lakeside Surfacing Limited | Construction | 2017 |
| Laketons Limited | Construction | 2003 |
| Lamp Consultants Limited | Administrative & support | 2015 |
| Lanair Consulting Limited | Professional & scientific | 2013 |
| Land Charter (Old Station Yard) Management Co Limited | Households | 2004 |
| Land Partners LLP | | 2011 |
| Lara Meze Grill Ltd | Hospitality | 2025 |
| Laura Frances Associates Limited | Arts & recreation | 2007 |
| Laureates Place (Binfield) Management Company Limited | Construction | 2016 |
| Lavenham Community Council | Arts & recreation | 2004 |
| Lavenham Literary Festival Limited | Arts & recreation | 2009 |
| Lavenham Photographic Studio Limited | Information & communication | 2003 |
| Lavenham Properties Solutions Limited | Real estate | 2022 |
| Lavenham Sanctuary Ltd | Agriculture & fishing | 2024 |
| Lavenham Studios Ltd | Real estate | 2012 |
| Lavenham Woodland Project Limited | Agriculture & fishing | 2003 |
| Lawn & Order (Suffolk) Ltd | Administrative & support | 2025 |
| LB Projects Limited | Construction | 2026 |
| LBG Machinery Limited | Wholesale & retail | 2013 |
| LCD Estates Ltd | Real estate | 2024 |
| LD Antiques Limited | Wholesale & retail | 2004 |
| LDA Trading Limited | Real estate | 2008 |
| LDS Consultants Limited | Information & communication | 2011 |
| Lealec Limited | Administrative & support | 2007 |
| Leanne's Cleaning Solutions Ltd | Administrative & support | 2025 |
| Leaway Developments Ltd | Construction | 2019 |
| LEE Wilson Building Services Limited | Construction | 2009 |
| Leedscompetitions Limited | Arts & recreation | 2025 |
| Leep Architects Limited | Professional & scientific | 2021 |
| Left Cross Ltd | Information & communication | 2023 |
| Leftbank Technology Ltd | Information & communication | 2024 |
| Lehe Consulting Ltd | Professional & scientific | 2024 |
| Leon and Sons Limited | Extraterritorial | 2004 |
| Leon Hoser Ltd | Professional & scientific | 2015 |
| Leopex Limited | Administrative & support | 2023 |
| Let's DO This Driving School Ltd | Education | 2024 |
| Letfree Ltd | Real estate | 2026 |
| Levor Limited | Hospitality | 2017 |
| Lewis Court (Dunmow) Management Company Limited | Households | 1982 |
| Lexicon Marketing Limited | Information & communication | 2012 |
| Liberator Film Productions Limited | Information & communication | 2019 |
| Liberator Film Services Limited | Information & communication | 2016 |
| Lifewide Limited | Information & communication | 2015 |
| Light UP Letters & Numbers Ltd | Extraterritorial | 2020 |
| Light Years Ahead Limited | Administrative & support | 2017 |
| Lighthouse Independent Financial Solutions Limited | Financial services | 2014 |
| Lightning Magic Shop Limited | Wholesale & retail | 2020 |
| Lilac House Limited | Construction | 2013 |
| Lily Group Holdings Limited | Professional & scientific | 2018 |
| Lime Copywriting Ltd | Professional & scientific | 2023 |
| Limetreestowmarket Limited | Manufacturing | 2024 |
| Lincoln Gardens Residents Management Company Limited | Households | 2011 |
| Lingley Design Ltd | Construction | 2017 |
| Link Britannia Limited | Construction | 2013 |
| Linkswood Veterinary Centre Limited | Professional & scientific | 1998 |
| Linton Plastic Moulders Limited | Manufacturing | 1980 |
| Lion Contractors Ltd | Construction | 2026 |
| Lipstick & Locks (Braintree) Limited | Other services | 2022 |
| Lipstick & Locks Bury ST Edmunds Limited | Other services | 2021 |
| Lipstick & Locks Halstead Limited | Other services | 2021 |
| Lipstick & Locks Sudbury Limited | Other services | 2021 |
| Lipstick & Locks Weddings Limited | Other services | 2021 |
| Lisa Knight Physiotherapy Ltd | Health & social care | 2014 |
| List House Management Co. Ltd | Households | 2007 |
| Little Acorn Media and Consultancy Ltd | Information & communication | 2025 |