| Kodie Stores Ltd | Wholesale & retail | 2024 |
| Koffee Hub Ltd | Hospitality | 2020 |
| Kogoda Ltd | Information & communication | 2025 |
| Kohana Limited | Wholesale & retail | 2024 |
| KOI Retail Ltd | Wholesale & retail | 2026 |
| Koios Navig Ltd | Professional & scientific | 2018 |
| Kolormaster Ireland Ltd | Manufacturing | 2015 |
| Komodo Learning Ltd | Information & communication | 2013 |
| Kompa International LP | | 2017 |
| Konnexion Limited | Information & communication | 1996 |
| Konrad Properties Ltd | Real estate | 1997 |
| Kontrast Supplements Ltd | Health & social care | 2018 |
| Koosion Industrial Co Limited | Wholesale & retail | 2025 |
| KOR CBT Limited | Health & social care | 2024 |
| KOR Properties Ltd | Other services | 2018 |
| Korana House Group Ltd | Wholesale & retail | 2025 |
| Korbstech Ltd | Information & communication | 2025 |
| Korentyre Limited | Professional & scientific | 2010 |
| Korgan Coffee Ltd | Hospitality | 2020 |
| Koridor Tech Limited | Information & communication | 2025 |
| Kotama BT7 Ltd | Hospitality | 2025 |
| Koway Hebuy Limited | Wholesale & retail | 2025 |
| Koworco Ltd | Real estate | 2018 |
| Kozzy Home Tekstil Sanayi Ticaret Limited | Wholesale & retail | 2026 |
| KP & Sons Foods Limited | Hospitality | 2025 |
| Kpath AI Ltd | Information & communication | 2025 |
| KPF Building & Civil Engineering Ltd | Construction | 2011 |
| KPH Enterprises Ltd | Wholesale & retail | 2015 |
| Kpme Limited | Other services | 2015 |
| Kpmg Trustees | Extraterritorial | 1975 |
| KPN Developments Limited | Real estate | 2004 |
| KPR Mechanical Ltd | Professional & scientific | 2014 |
| Kprad Soft Limited | Information & communication | 2014 |
| KPS Products Ltd | Wholesale & retail | 2022 |
| Kraftcode Ltd | Information & communication | 2024 |
| Krafthaus Design Ltd | Professional & scientific | 2018 |
| Krasimir CHA Ltd | Wholesale & retail | 2024 |
| Kraygsoft Limited | Information & communication | 2023 |
| Kreed Digital Ltd | Wholesale & retail | 2025 |
| KRG Health & Safety Consultancy Ltd | Professional & scientific | 2017 |
| Kris Stronge Limited | Information & communication | 2017 |
| Kris Turnbull Limited | Professional & scientific | 2007 |
| Kriski International Limited | Wholesale & retail | 2025 |
| Kristen Coco Limited | Wholesale & retail | 2022 |
| Kristian Nairn Productions Ltd | Professional & scientific | 2014 |
| Kristina Murray & Company Limited | Professional & scientific | 2012 |
| KRK Management Ltd | Households | 2023 |
| Kronos North West Ltd | Real estate | 2024 |
| Krumb Bakery Limited | Wholesale & retail | 2025 |
| Krust & KO Limited | Hospitality | 2024 |
| KRW Law Advocates Limited | Professional & scientific | 2012 |
| KRW Law LLP | | 2012 |
| KS Films Ltd | Information & communication | 2024 |
| KS PK Limited | Wholesale & retail | 2025 |
| KSC Belfast Ltd | Manufacturing | 2017 |
| KSC Consult & Design Ltd | Wholesale & retail | 2025 |
| KSC Cosmetics (UK) Ltd | Wholesale & retail | 2020 |
| KSD Ireland Ltd | Construction | 2016 |
| Ksfl Ltd | Financial services | 2024 |
| Kspacefood Ltd | Hospitality | 2025 |
| KSS Belfast Ltd | Administrative & support | 2024 |
| Kstc Limited | Administrative & support | 2009 |
| KT Crypto Mining Consortium Limited | Information & communication | 2021 |
| KT Developments Limited | Construction | 2006 |
| KT Mining Consortium Limited | Information & communication | 2021 |
| KT Quality Products (UK) Limited | Wholesale & retail | 2025 |
| KT Restaurant Limited | Hospitality | 2014 |
| KT2POINT0 Ltd | Information & communication | 2022 |
| KTR Services Ltd | Construction | 2017 |
| KTV NI Limited | Wholesale & retail | 2024 |
| KTW Distribution Ltd | Wholesale & retail | 2002 |
| Kube Developments Limited | Real estate | 2003 |
| Kudos Executive Transfer Ltd | Transport & logistics | 2006 |
| Kudos IT Consultancy Ltd | Information & communication | 2003 |
| Kudos Property Management Ltd | Real estate | 2015 |
| Kugo Management Services Limited | Real estate | 2025 |
| Kul-Kis Limited | Manufacturing | 1985 |
| Kulawe Limited | Information & communication | 2010 |
| Kumiko's Cat Lounge Ltd | Hospitality | 2025 |
| Kuper Limited | Information & communication | 2026 |
| Kura Connect Ltd | Administrative & support | 2025 |
| Kurdish Barber (Dundonald) Ltd | Other services | 2023 |
| Kurinchi Ltd | Wholesale & retail | 2026 |
| Kurosh Ltd | Construction | 2017 |
| Kurrito PVT Limited | Hospitality | 2018 |
| Kusadaski Kutts Barbers Limited | Other services | 2026 |
| Kush-Ila Limited | Professional & scientific | 2024 |
| Kushu Tech Ltd | Information & communication | 2019 |
| Kutunza Watoto | Other services | 2017 |
| Kuukyo Ltd | Information & communication | 2025 |
| Kuumo Ltd | Manufacturing | 2026 |
| Kvlr Ltd | Arts & recreation | 2020 |
| KW Co One Hundred Limited | Financial services | 2026 |
| KW Legal Services Ltd | Professional & scientific | 2015 |
| Kwmc Ltd | Hospitality | 2019 |
| KY Square Property Group Ltd | Administrative & support | 2025 |
| Kyaan Ltd | Wholesale & retail | 2025 |
| Kyber Belfast Ltd | Hospitality | 2025 |
| KYC 8 Ltd | Hospitality | 2019 |
| Kyle Seek Limited | Wholesale & retail | 2025 |