| Kindred Property York Ltd | Hospitality | 2025 |
| Kindred Spaces Ltd | Real estate | 2021 |
| Kinetic Driving Tuition Ltd | Education | 2024 |
| Kinetic Fusion Ltd | Professional & scientific | 2023 |
| Kinetic Resources & Sons Ltd | Administrative & support | 2025 |
| Kinfauns Veterinary Centre Limited | Extraterritorial | 2008 |
| King SBC Ltd | Wholesale & retail | 2019 |
| King's Joinery (York) Limited | Construction | 2006 |
| Kingfisher 4 Properties Limited | Real estate | 2017 |
| Kingfisher Care Services York Ltd | Public administration | 2025 |
| Kingfisher Consultants (Yorkshire) Ltd | Administrative & support | 2025 |
| Kingpay Limited | Financial services | 2014 |
| Kings Bounty Equine Practice Limited | Professional & scientific | 2013 |
| Kings Carpets and Flooring (York) Ltd | Wholesale & retail | 2025 |
| Kings Cloisters Management Company Limited | Real estate | 2024 |
| Kings Grove Cranbrook Management Company Limited | Households | 2014 |
| Kingsbridge Court (Gorseinon) Management Company Limited | Households | 2015 |
| Kingsbury Gardens (ST Albans) Residents Management Company Limited | Households | 2018 |
| Kingsbury Meadows (Wakefield) Management Company Limited | Households | 2016 |
| Kingsgate (Northallerton) Residents Management Company Limited | Real estate | 2024 |
| Kingshay Farming and Conservation Limited | Professional & scientific | 1991 |
| Kingsley Mews Management Company Limited | Households | 2024 |
| Kingsmead (Gloucester) Management Company Limited | Households | 2015 |
| Kingston Timber Frame Limited | Construction | 2003 |
| Kingswood Rentals Ltd | Real estate | 2023 |
| Kinma Ltd | Real estate | 2024 |
| KINNERTON358 Limited | Professional & scientific | 2013 |
| Kiosk (York) Limited | Wholesale & retail | 2018 |
| Kiosk Tanghale Ltd | Wholesale & retail | 2020 |
| Kirby Aviation Ltd | Transport & logistics | 2016 |
| Kirby Joinery Limited | Manufacturing | 1999 |
| Kirkburn Biomass Services LLP | | 2013 |
| Kirkby Computers Ltd | Agriculture & fishing | 2005 |
| Kirkby Mills Garage Services Ltd | Wholesale & retail | 2018 |
| Kirkby Star Foods Ltd | Hospitality | 2019 |
| Kirkbymoorside and District PRE School Playgroup Limited | Education | 2011 |
| Kirkbymoorside Golf Club Limited | Hospitality | 1990 |
| Kirkdale Court Management Limited | Households | 1986 |
| Kirkdale Manor Freehold Company Limited | Real estate | 2021 |
| Kirkdale Manor Management Company Limited | Households | 2006 |
| Kirkgate Childcare Limited | Health & social care | 2017 |
| Kirkman Seitz Limited | Professional & scientific | 2015 |
| Kirkminster Engineering Limited | Real estate | 2005 |
| Kissmeright Limited | Wholesale & retail | 2025 |
| Kitbids Limited | Administrative & support | 2026 |
| Kitchen & Cocktails Ltd | Hospitality | 2025 |
| Kitchen Leemo Ltd | Hospitality | 2018 |
| Kitchen Rescue Ltd | Other services | 2010 |
| Kitchen ZEN Ltd | Manufacturing | 2025 |
| Kitchens & Interiors Constructions Ltd | Construction | 2018 |
| KITE360 Ltd | Professional & scientific | 2025 |
| Kitson Bespoke Ltd | Construction | 2022 |
| Kitsune Studios Ltd | Information & communication | 2021 |
| KJ Global Trading Ltd | Wholesale & retail | 2026 |
| KJS Surveying Ltd | Agriculture & fishing | 2025 |
| KJW Leisure Limited | Professional & scientific | 2017 |
| KK Swproperties Ltd | Real estate | 2022 |
| KK TW Properties Ltd | Real estate | 2022 |
| Kkreations LLP | | 2023 |
| KL Consulting Services Limited | Professional & scientific | 2026 |
| KLB Property Ltd | Real estate | 2023 |
| Kleen KAR Limited | Administrative & support | 2020 |
| Kleijnen Systematic Reviews Limited | Professional & scientific | 2005 |
| Kleiser's ALE House & Spirit Merchant Ltd | Wholesale & retail | 2025 |
| Klkl 1966 Limited | Extraterritorial | 2014 |
| KLL Leisure Limited | Administrative & support | 2017 |
| Klohn Crippen Berger (UK) Limited | Professional & scientific | 2018 |
| KLS at Bryns Ltd | Wholesale & retail | 2026 |
| KLS Business Consultants Limited | Professional & scientific | 2008 |
| KLT Supply Chain Services Ltd | Professional & scientific | 2021 |
| KLT Trading Limited | Manufacturing | 2023 |
| KM Adults Care & Health Consultancy Ltd | Health & social care | 2026 |
| KM Game Limited | Wholesale & retail | 2011 |
| KM School Limited | Education | 1990 |
| Kmbre Ltd | Professional & scientific | 2026 |
| Kmnw Ltd | Administrative & support | 2012 |
| KMS Brickwork Ltd | Construction | 2016 |
| Knaresborough Padel Ltd | Arts & recreation | 2025 |
| Knavesmire Consulting Ltd | Professional & scientific | 2020 |
| Knavesmire Creative Ltd | Information & communication | 2018 |
| Knavesmire Ltd | Professional & scientific | 2012 |
| Knavesmire Properties Limited | Real estate | 2017 |
| Knavesmire Services Limited | Professional & scientific | 2024 |
| Knight Securities Ltd | Real estate | 2021 |
| Knight's Manor Estates Ltd | Real estate | 2026 |
| Knights Court (Old Sarum) Management Company Limited | Households | 2016 |
| Knightsmoor Homes Limited | Extraterritorial | 1960 |
| Knoladex Ltd | Information & communication | 2022 |
| Knole Properties (York) Limited | Real estate | 1999 |
| Knotty OWL Hospitality Ltd | Hospitality | 2023 |
| Knowle House Accountants Limited | Professional & scientific | 2022 |
| Knowledgeablee Instructor Training Ltd | Education | 2022 |
| Knowles (York) Limited | Construction | 2011 |
| Knowles Farming Limited | Agriculture & fishing | 2007 |
| Knox Mcconnell Architects Ltd | Professional & scientific | 2012 |
| Koalascrossing Ltd | Health & social care | 2023 |
| Kobayashi Maru (Yorkshire) Ltd | Real estate | 2025 |
| Kobillow Ltd | Professional & scientific | 2023 |
| Kocyk Construction Limited | Construction | 2014 |
| Koda's Realm Ltd | Hospitality | 2026 |