| Krahuk Limited | Information & communication | 2022 |
| Kraken Catering Ltd | Hospitality | 2024 |
| Kraken Kevin Totton Limited | Wholesale & retail | 2016 |
| Kraken Projects Ltd | Construction | 2024 |
| Kraken Shaun Martin Ltd | Wholesale & retail | 2016 |
| Krakow Polish Foods Ltd | Wholesale & retail | 2017 |
| Krellian Ltd | Wholesale & retail | 2020 |
| KRF Engineering Limited | Construction | 2015 |
| KRH (NE) Ltd | Hospitality | 2019 |
| KRH Paving and Groundworks Ltd | Construction | 2026 |
| Krich IT Consultants Limited | Information & communication | 2010 |
| Krikboh Holdings Ltd | Real estate | 2018 |
| Kriminal INK Ltd | Arts & recreation | 2025 |
| Kripanand Ltd | Hospitality | 2024 |
| Kris Gofton Holdings Limited | Financial services | 2025 |
| Krishna Cool Ltd | Manufacturing | 2021 |
| Krispy COD Limited | Hospitality | 2019 |
| KRM Promotions Ltd | Information & communication | 2026 |
| KRO (JG) Limited | Administrative & support | 2025 |
| Krolltek Limited | Wholesale & retail | 2019 |
| Kronix Studio Ltd | Information & communication | 2026 |
| KRS (NE) Ltd | Financial services | 2020 |
| Krushbykatie Ltd | Wholesale & retail | 2025 |
| Krysalis Support Ltd | Other services | 2012 |
| KS (Associate) Ltd | Health & social care | 2019 |
| KSA FAM Investments Limited | Financial services | 2018 |
| Ksang Ltd | Health & social care | 2025 |
| KSB Birmingham Limited | Construction | 2017 |
| Kscowgateminimarket Ltd | Wholesale & retail | 2022 |
| KSD Builders Ltd | Administrative & support | 2018 |
| KSE Offshore Limited | Other services | 2023 |
| KSL Rail Limited | Construction | 2019 |
| Ksmb Ltd | Wholesale & retail | 2018 |
| KT Core Solutions Ltd | Professional & scientific | 2021 |
| KT Dodd Limited | Professional & scientific | 2014 |
| KT Flooring Holdings Ltd | Financial services | 2024 |
| KT Flooring Ltd | Construction | 2021 |
| KT Nails 155 Ltd | Other services | 2024 |
| KT Safety Ltd | Professional & scientific | 2025 |
| KT Ventures Limited | Real estate | 2024 |
| KU Group Ltd | Wholesale & retail | 2022 |
| Kubota Noodle Express UK Ltd | Manufacturing | 2022 |
| Kubrick Investments Ltd | Professional & scientific | 2009 |
| Kubus Store Ltd | Wholesale & retail | 2025 |
| Kuda Limited | Wholesale & retail | 2024 |
| Kudhil Ltd | Real estate | 2025 |
| Kudos Linen Hire Limited | Administrative & support | 2016 |
| Kuffeyah Ltd | Wholesale & retail | 2024 |
| Kular Property Investments Limited | Real estate | 2021 |
| Kulture Klub Training Ltd | Other services | 2025 |
| Kulvert Books CIC | Information & communication | 2024 |
| Kupanda Kuvuna Limited | Administrative & support | 2013 |
| Kurd Property Limited | Real estate | 2026 |
| Kurek Utilities and Construction Ltd | Construction | 2024 |
| Kurious Arts Limited | Arts & recreation | 2019 |
| Kuver Limited | Health & social care | 2024 |
| KW Site Welding Ltd | Construction | 2026 |
| Kwan HOI International Company Limited | Manufacturing | 2024 |
| Kwan HOI Property Holding Company Limited | Real estate | 2024 |
| Kwick FIX Auto Care Ltd | Wholesale & retail | 2024 |
| Kwick Tyres Ltd | Wholesale & retail | 2013 |
| KWM Talent Management Limited | Administrative & support | 2019 |
| Kwok BO Limited | Hospitality | 2014 |
| KWP (Newcastle) Limited | Real estate | 2023 |
| KWT Property Services Limited | Real estate | 2026 |
| Kwusi Ltd | Hospitality | 2019 |
| Kyage Construction Limited | Construction | 2012 |
| Kyda Group Limited | Other services | 2025 |
| Kyloe Developments Ltd | Construction | 2023 |
| Kyloe Limited | Construction | 2023 |
| KYO Developments Ltd | Construction | 2018 |
| KZ Barbers Ltd | Other services | 2025 |
| L & a Property Investments (North East) Limited | Real estate | 2021 |
| L & J Accounting Services Limited | Professional & scientific | 2004 |
| L & J Enterprises Limited | Administrative & support | 2008 |
| L & S Properties and Management Services Ltd | Real estate | 2025 |
| L Burns Joinery & Building Solutions Ltd | Construction | 2024 |
| L C Anderson Limited | Professional & scientific | 2011 |
| L C S J Ltd | Construction | 2007 |
| L Harold Limited | Professional & scientific | 2026 |
| L Hopper Joinery and Building Services Limited | Construction | 2013 |
| L Liti Limited | Hospitality | 2025 |
| L M C Retailing Limited | Wholesale & retail | 2016 |
| L Plastering & Damp Proofing Ltd | Extraterritorial | 2024 |
| L R Heating Services Ltd | Construction | 2024 |
| L R S Accountancy Services Ltd | Professional & scientific | 2003 |
| L W C 88 Ltd | Hospitality | 2019 |
| L&C Property Group Ltd | Real estate | 2024 |
| L&M Groundworks Limited | Construction | 2023 |
| L&S NE Ltd | Hospitality | 2026 |
| L&V Legal Consultancy Ltd | Professional & scientific | 2020 |
| L'Aquila Property Development Ltd | Real estate | 2020 |
| L. N. R. Plumbing and Heating Limited | Construction | 2003 |
| L.& N.Property Investment Co.Limited(The) | Real estate | 1959 |
| L.A.S Joinery Ltd | Construction | 2025 |
| L.B. Foster Rail Technologies (UK) Limited | Manufacturing | 2000 |
| L.E.A. Properties (NE) Limited | Real estate | 2016 |
| L.M. Longstaff Limited | Health & social care | 2009 |
| L.R Building & Maintenance Ltd | Construction | 2024 |
| LA Casa Delicatessen Ltd | Wholesale & retail | 2015 |