| Kebab Station Jaar Ltd | Hospitality | 2025 |
| KEE Commercial Ltd | Real estate | 2022 |
| Keel Properties Limited | Construction | 2003 |
| Keeland Limited | Information & communication | 2023 |
| Keeldra Limited | Wholesale & retail | 2013 |
| Keen 2B Green C.I.C. | Professional & scientific | 2024 |
| Keen TEK Holding (UK) Limited | Financial services | 2025 |
| Keenan (HR) Consulting Limited | Professional & scientific | 2005 |
| Keenan Corporate Finance Limited | Financial services | 2012 |
| Keenan EAR Clinic Limited | Extraterritorial | 2022 |
| Keenan Management Ltd | Construction | 2026 |
| Keenan Quantity Surveyors (NI) Ltd | Professional & scientific | 2020 |
| Keenan Seafood Limited | Wholesale & retail | 1991 |
| Keenan Solicitors Limited | Professional & scientific | 2011 |
| Keenwood Construction Holdings Limited | Financial services | 2023 |
| Keenwood Construction Ltd | Construction | 2002 |
| Keenwood Micran Holdings Limited | Financial services | 2026 |
| Keenwood Properties Ltd | Real estate | 2020 |
| Keenwood Property Holdings Limited | Financial services | 2023 |
| Keep Look Forward Ltd | Wholesale & retail | 2025 |
| Keep Northern Ireland Beautiful | Other services | 2000 |
| Keep Your Profits Ltd | Administrative & support | 2025 |
| Keeyvii Ltd | Wholesale & retail | 2024 |
| KEG Vault Ltd | Wholesale & retail | 2025 |
| Keightley Court Management Company Limited | Households | 2003 |
| Keith Drury Art Ltd | Arts & recreation | 2015 |
| Keith Kane Hair Ltd | Other services | 2008 |
| Keith Leary Ltd | Wholesale & retail | 2025 |
| Keith Maxwell Limited | Information & communication | 2018 |
| Kekoil Ltd | Wholesale & retail | 2026 |
| Kelif Limited | Wholesale & retail | 2024 |
| Kells BES Ltd | Energy | 2018 |
| Kelly Apartments Management Company Limited | Extraterritorial | 2001 |
| Kelly Chiropractic Care Limited | Health & social care | 2008 |
| Kelly Earthmoving Limited | Agriculture & fishing | 2011 |
| Kelly Heating Services Ltd | Construction | 2022 |
| Kelly Hunter Trading Limited | Wholesale & retail | 2010 |
| Kelly Inc. Limited | Construction | 2024 |
| Kelly Jennings & Associates Ltd | Administrative & support | 2020 |
| Kelly Renewables Ltd | Construction | 2022 |
| Kelly Solicitors Limited | Professional & scientific | 2021 |
| Kellyvision Imaging Limited | Health & social care | 2022 |
| Kelmar Solutions Ltd | Professional & scientific | 2026 |
| Kelmel Ltd | Professional & scientific | 2012 |
| Kelowna Properties Ltd | Financial services | 2021 |
| Kelpai Limited | Agriculture & fishing | 2026 |
| Kelsius Limited | Information & communication | 2008 |
| Keltico Ltd | Wholesale & retail | 2024 |
| Kelvin Malone Bridge Centre | Arts & recreation | 2012 |
| Kelvin Old Boys Football Club Limited | Hospitality | 2023 |
| Kemad Limited | Information & communication | 2015 |
| Kemang Ltd | Extraterritorial | 2013 |
| Kemark NO.2 Limited | Real estate | 2002 |
| Kemek Ltd | Manufacturing | 1973 |
| Kemfast Pass Investments Limited | Transport & logistics | 2014 |
| Kemfast Pass N.I. Ltd | Transport & logistics | 2019 |
| Kemou Ltd | Hospitality | 2025 |
| Kempestone Engineering Ltd | Manufacturing | 2025 |
| KEN Green Tattoos Ltd | Arts & recreation | 2018 |
| Keneagles Limited | Construction | 2021 |
| Kenkyoq Limited | Wholesale & retail | 2025 |
| Kennedy & Carr UK Limited | Administrative & support | 2022 |
| Kennedy Business Services Ltd | Administrative & support | 2021 |
| Kennedy Centre P.O. Ltd | Wholesale & retail | 2013 |
| Kennedy Employment Solutions Limited | Administrative & support | 2012 |
| Kennedy Estate Management Ltd | Real estate | 2025 |
| Kennedy Fitzgerald Architects LLP | | 2008 |
| Kennedy Holdings (Coleraine) Limited | Construction | 1961 |
| Kennedy Mort Consultancy Limited | Professional & scientific | 2018 |
| Kennedy Project Management (NI) Limited | Professional & scientific | 2019 |
| Kennedy Recruitment Ltd | Administrative & support | 1997 |
| Kennedys Belfast LLP | | 2010 |
| Kennetix Electrical Services Ltd | Construction | 2026 |
| Kenny Adair Limited | Manufacturing | 2022 |
| Kenoan Properties Limited | Administrative & support | 2016 |
| Kensington Apartments Management Company Limited | Households | 1999 |
| Kensington House Design Ltd | Construction | 2024 |
| Kensington Lodge (Belfast) Management Company Ltd | Households | 2012 |
| Kentwood Estates Limited | Real estate | 2007 |
| Kenwell Engineering Ltd | Manufacturing | 2014 |
| KENZO73 Ltd | Health & social care | 2025 |
| Keoghs Northern Ireland LLP | | 2019 |
| Keos Cardiac Ltd | Health & social care | 2025 |
| Kepler Green Ltd | Wholesale & retail | 2023 |
| KER Graphics Unlimited | Manufacturing | 2005 |
| Kerbachehr Ltd | Administrative & support | 2023 |
| Kerbside Motors Belfast Ltd | Wholesale & retail | 2012 |
| Kerim Annamyradov Limited | Wholesale & retail | 2024 |
| Kernan Holdings Limited | Financial services | 2022 |
| Kerosene Spill Remediation Ltd | Construction | 2023 |
| Kerr Family Estates Limited | Real estate | 2024 |
| Kerr Henderson (Financial Services) Limited | Financial services | 1962 |
| Kerr Prop Two Limited | Construction | 2017 |
| Kerr Property Holdings Limited | Professional & scientific | 2017 |
| Kerragh Properties Ltd | Extraterritorial | 2018 |
| Kerragh Rock Ltd | Extraterritorial | 2017 |
| Kerrisdale Properties Limited | Construction | 2018 |
| Kerry Thompson Psychology Services Ltd | Education | 2024 |
| Kerrybrooke Limited | Professional & scientific | 2014 |
| Kersten Hunik (N.I.) Limited | | 1985 |