| Kezog Built and Design Limited | Construction | 2020 |
| KF Specialist Cleaning Ltd | Administrative & support | 2024 |
| KG Constructs Ltd | Construction | 2026 |
| KH E-Commerce Ltd | Wholesale & retail | 2025 |
| Khalid Blackfen Ltd | Other services | 2021 |
| Khans Barbers Ltd | Other services | 2021 |
| Khfm Ltd | Construction | 2022 |
| KIE Properties Limited | Real estate | 2021 |
| Killavoher Investments Ltd | Real estate | 2017 |
| Kilo FM Limited | Professional & scientific | 2024 |
| Kimmicass Limited | Wholesale & retail | 2015 |
| Kimmis CAB Co. Ltd | Transport & logistics | 2026 |
| Kingfisher Professional Limited | Information & communication | 2017 |
| Kings Roofing & Building Limited | Administrative & support | 2021 |
| Kingsley's 24/7 Cleaning Services Limited | Administrative & support | 2024 |
| Kingsway Enterprises (UK) Limited | Manufacturing | 2012 |
| Kingsway Group Global Limited | Financial services | 2018 |
| Kingswood Contract Interiors Limited | Construction | 2020 |
| Kinland (Brockley) Limited | Construction | 2022 |
| Kinland (RR Clapham) Limited | Construction | 2021 |
| Kinland (SS Kensington) Ltd | Construction | 2024 |
| Kinland (URR Richmond) Limited | Construction | 2023 |
| Kinland Development Management Limited | Construction | 2024 |
| Kinland Limited | Construction | 2021 |
| Kinnear Air Conditioning Limited | Administrative & support | 2021 |
| Kiran Ashwin Properties Limited | Real estate | 2020 |
| Kirkham M & Co Ltd | Hospitality | 2025 |
| Kiru Retailers Ltd | Wholesale & retail | 2025 |
| Kitchen Secrets Limited | Hospitality | 2011 |
| Kitson Films Limited | Information & communication | 2017 |
| Kittolily Ltd | Real estate | 2022 |
| Kjbb Cabs Limited | Transport & logistics | 2025 |
| KK31 Holdings Limited | Financial services | 2020 |
| Kleverclogs Limited | Health & social care | 2023 |
| KLM Collective Limited | Construction | 2026 |
| KLM Electrical Services Ltd | Construction | 2009 |
| KLR Solicitors Limited | Professional & scientific | 2005 |
| Kltobin Ltd | Professional & scientific | 2026 |
| KM Carehomes Limited | Health & social care | 2016 |
| KM Celebrations Ltd | Administrative & support | 2022 |
| KM Facilities Ltd | Administrative & support | 2020 |
| KM Recruitment Services Limited | Administrative & support | 2023 |
| KMO Property Limited | Real estate | 2023 |
| KMS Logisticss Ltd | Transport & logistics | 2026 |
| KMS Voice and Fire Systems Ltd | Manufacturing | 2018 |
| Knapman & Sons (Builders) Limited | Other services | 1977 |
| Knapman.Com Limited | Other services | 2019 |
| Knights Build & Plastering Limited | Construction | 2025 |
| Knights Party Wall Surveying Ltd | Professional & scientific | 2025 |
| Kntc EOT Limited | Administrative & support | 2023 |
| Kntc Limited | Construction | 2011 |
| Kodo Consulting Ltd | Professional & scientific | 2019 |
| Koho Kiva Ltd | Construction | 2014 |
| Koizen Limited | Construction | 2004 |
| Komfig Ltd | Professional & scientific | 2022 |
| Kong Developments Ltd | Construction | 2018 |
| Kosh Creatives Limited | Arts & recreation | 2015 |
| Kovil Consultancy Ltd | Construction | 2015 |
| Kovil Properties Ltd | Real estate | 2024 |
| Koyo Wellness Limited | Arts & recreation | 2023 |
| KPM Developments Limited | Construction | 2016 |
| KPPM2 Limited | Professional & scientific | 2011 |
| KPT Holdings Limited | Financial services | 2023 |
| KPW Garden Services Ltd. | Other services | 2020 |
| Kraft Automotive Ltd | Wholesale & retail | 2026 |
| Kranikan Ltd | Construction | 2019 |
| Kreative Technologies Ltd. | Information & communication | 2012 |
| Krieder (UK) Limited | Construction | 2002 |
| Krieder Limited | Professional & scientific | 2006 |
| KRS Investments Ltd | Administrative & support | 2016 |
| Kryten Computing Limited | Information & communication | 2024 |
| Ksax Limited | Information & communication | 2020 |
| Ksixtysix UK Limited | Arts & recreation | 2017 |
| KSK20 Holdings Limited | Financial services | 2020 |
| Kspb London Ltd | Administrative & support | 2021 |
| Ktcl Limited | Construction | 2014 |
| Ktsmsolutions Ltd. | Information & communication | 2017 |
| KUF Limited | Financial services | 2015 |
| Kuijpers Balfour Holdings Limited | Financial services | 2016 |
| Kuijpers-Balfour Ltd. | Wholesale & retail | 1987 |
| Kurtis Finn Limited | Professional & scientific | 2016 |
| Kush Music Limited | Administrative & support | 2017 |
| Kussan Ltd | Hospitality | 2012 |
| KV Construction Ltd | Construction | 2025 |
| KVC Midas Limited | Construction | 2021 |
| KVC Properties Limited | Real estate | 2012 |
| KVH 07 Limited | Real estate | 2025 |
| KVH 77 Limited | Real estate | 2024 |
| KW Styling & Image Consultancy Ltd | Other services | 2014 |
| Kwik Pass MOT Ltd | Wholesale & retail | 2026 |
| Kyle Parry Limited | Construction | 2014 |
| Kylo & IBS Construction Limited | Construction | 2022 |
| KZK Property Limited | Real estate | 2023 |
| L & B Installations Limited | Other services | 2015 |
| L & C Solutions Ltd | Professional & scientific | 2012 |
| L & G Forest Products Limited | Real estate | 2021 |
| L & P Consultants (Kent) Ltd | Administrative & support | 2021 |
| L & V Property Lease Limited | Real estate | 2023 |
| L a Toolbase Limited | Information & communication | 2006 |
| L B Planning Solutions Limited | Transport & logistics | 2018 |