| Kobec Limited | Real estate | 2015 |
| Koeablew Ltd | Wholesale & retail | 2025 |
| Komatiitic Limited | Wholesale & retail | 2025 |
| KOQ Ltd | Hospitality | 2022 |
| Koton Trading Limited | Wholesale & retail | 2024 |
| Kreo Traders Ltd | Wholesale & retail | 2026 |
| Kristine Bogdanova Limited | Wholesale & retail | 2025 |
| Kruugpower Directpromotions Ltd | Wholesale & retail | 2015 |
| Krzysztof Zenon Baron Ltd | Wholesale & retail | 2023 |
| Kubby Limited | Education | 2015 |
| Kusch Georg Ltd | Wholesale & retail | 2023 |
| Kwamc Limited | Wholesale & retail | 2025 |
| Kygnt Ltd | Wholesale & retail | 2025 |
| L'Amore World Travel Ltd | Administrative & support | 2018 |
| LA Asian Cuisine Ltd | Hospitality | 2025 |
| LA Croft Civils Ltd | Construction | 2026 |
| LA Luxe Nails & Spa Ltd | Other services | 2025 |
| LA MON House Limited | Extraterritorial | 1973 |
| Laburnumhill Properties Limited | Manufacturing | 2007 |
| Ladygogo Shopping Limited | Wholesale & retail | 2025 |
| Lagan Networks Ltd | Information & communication | 2022 |
| Lagan Stream Trading Ltd | Wholesale & retail | 2025 |
| Lahore Chicken Shack Ltd | Hospitality | 2013 |
| Lahore Kebab House Newtownards Ltd | Hospitality | 2013 |
| Lakeland Dairies Co-Op Limited | Wholesale & retail | 2021 |
| Lakeland Dairy Sales Limited | Wholesale & retail | 2021 |
| Lance LAB Ltd | Manufacturing | 2013 |
| Land Investment and Planning Services Limited | Professional & scientific | 2016 |
| Landscape Supplies (Ireland) Limited | Agriculture & fishing | 2014 |
| Lannyeots Limited | Wholesale & retail | 2025 |
| Lanyon (NI) Limited | Administrative & support | 2007 |
| Lark Financial Limited | Wholesale & retail | 2023 |
| Laserhpuderetail Ltd | Wholesale & retail | 2025 |
| Laserkris Ltd | Manufacturing | 2019 |
| Laurel Financial Solutions Ltd | Construction | 2025 |
| Lawlor Construction Ltd | Manufacturing | 2023 |
| LD TV Rentals Ltd | Administrative & support | 2020 |
| LE Pritchitt (Northern Ireland) Limited | Administrative & support | 2005 |
| Leaf Training Ltd | Education | 2024 |
| Learning ME Ltd | Education | 2021 |
| Learning Works Partnership LLP | | 2015 |
| LEE Adams Ltd | Wholesale & retail | 2025 |
| Leeshow Limited | Wholesale & retail | 2024 |
| Legacy Properties N.I Limited | Real estate | 2022 |
| Lehtola Tervaharju Limited | Wholesale & retail | 2023 |
| Leigh EMI Limited | Wholesale & retail | 2025 |
| Leishman Engineering Limited | Professional & scientific | 2023 |
| Lenamore Developments Limited | Construction | 2006 |
| Lennon Equine Ltd | Agriculture & fishing | 2018 |
| Lescann Limited | Wholesale & retail | 2025 |
| Lesleety Limited | Wholesale & retail | 2025 |
| Lessetone Limited | Wholesale & retail | 2025 |
| Lewis Duff Car Sales Ltd | Wholesale & retail | 2025 |
| Lexie Catering Ltd | Hospitality | 2019 |
| Lexie Trading Ltd | Wholesale & retail | 2014 |
| LGR Builders Ltd | Construction | 2019 |
| Liamfithz Limited | Wholesale & retail | 2025 |
| Lianhttz Limited | Wholesale & retail | 2025 |
| Lifegap Ltd | Education | 2019 |
| Lifestyle Home Works Ltd | Construction | 2023 |
| Lighthouse Church Donaghadee Ltd | Other services | 2023 |
| Lighthouse DC Ltd | Professional & scientific | 2025 |
| Lighthouse Developments (N.I.) Limited | Construction | 2012 |
| Lihimay Limited | Manufacturing | 2024 |
| Lihuahai Limited | Manufacturing | 2024 |
| Lijink Limited | Wholesale & retail | 2024 |
| Limeforge Ltd | Professional & scientific | 2013 |
| Limitless Fitness Ltd | Arts & recreation | 2024 |
| Line Design Medical Art Ltd | Arts & recreation | 2020 |
| Linen Schoolhouse Ltd | Administrative & support | 2025 |
| Link Family and Community Centre-The | Health & social care | 2002 |
| Linking Generations Northern Ireland Ltd | Other services | 2025 |
| Linkle Ecommerce Limited | Wholesale & retail | 2025 |
| Linqiqi Limited | Wholesale & retail | 2024 |
| Linqx Technology Ltd | Wholesale & retail | 2026 |
| Lioitts Limited | Wholesale & retail | 2025 |
| Liqing Limited | Wholesale & retail | 2024 |
| Liquid Smok Ltd | Information & communication | 2025 |
| Lisbarnet 1967 Limited | Extraterritorial | 2013 |
| Lisburn Eats Ltd | Information & communication | 2021 |
| Little Doves Limited | Health & social care | 2004 |
| Little KU Ltd | Wholesale & retail | 2024 |
| Little Ping Limited | Wholesale & retail | 2024 |
| Little POP Marketing Ltd | Information & communication | 2019 |
| Liugang Ltd | Wholesale & retail | 2025 |
| Liujie Limited | Wholesale & retail | 2025 |
| Livdeal Trading Limited | Wholesale & retail | 2022 |
| Live Edge Whisperer Limited | Manufacturing | 2025 |
| Live TEC Engineering Limited | Professional & scientific | 2014 |
| Liveliness Thriving Ltd | Wholesale & retail | 2024 |
| Living Branch Ministries | Other services | 2016 |
| LIWEIBIN1 Ltd | Wholesale & retail | 2025 |
| Lixiangcai Limited | Wholesale & retail | 2023 |
| Lixiaocheng Limited | Wholesale & retail | 2025 |
| Liyuce Limited | Wholesale & retail | 2024 |
| Lizhigui Ltd | Wholesale & retail | 2024 |
| Llaer ZRI Limited | Wholesale & retail | 2025 |
| Lliam TON Limited | Wholesale & retail | 2025 |
| Llipmas Limited | Wholesale & retail | 2025 |
| LMC Growth & Strategy Ltd | Professional & scientific | 2026 |