| Jools Tools Limited | Administrative & support | 2021 |
| Joseph & Co Cleaning Services Ltd | Administrative & support | 2026 |
| Jowett & Jowett Limited | Construction | 2011 |
| Jphm Limited | Administrative & support | 2012 |
| JPS Catering Ltd | Hospitality | 2023 |
| JR Event Services Ltd | Administrative & support | 2009 |
| JS Homes SW Ltd | Construction | 2023 |
| JSB Services Ltd | Construction | 2020 |
| Jsolutions Property Ltd | Real estate | 2021 |
| JSS (UK) Limited | Information & communication | 1999 |
| JSS Europe Limited | Administrative & support | 2021 |
| JST Engineers Ltd | Manufacturing | 2023 |
| JT Quantity Surveying Limited | Professional & scientific | 2016 |
| Junction 24 Limited | Agriculture & fishing | 2006 |
| Jungle Town 2.0 Ltd | Arts & recreation | 2025 |
| Jurgen Properties Ltd | Real estate | 2019 |
| Just a Sharp Scratch Media Ltd | Information & communication | 2025 |
| Just for Pets Direct Ltd | Information & communication | 2024 |
| Just Ofada Foods Ltd | Hospitality | 2025 |
| Justin Motors Ltd | Wholesale & retail | 2024 |
| JW61AFC Ltd | Professional & scientific | 2025 |
| Jwalton Consultancy Ltd | Information & communication | 2026 |
| JWE Partners Limited | Administrative & support | 2010 |
| JZS Solutions Ltd | Professional & scientific | 2025 |
| K & M Construction (UK) Ltd | Construction | 2004 |
| K L Structural Steel Limited | Construction | 2008 |
| K Nichols Properties Ltd | Real estate | 2021 |
| K&R Properties (Bristol) Ltd | Real estate | 2020 |
| K. Williams Limited | Health & social care | 2015 |
| K.D. Success Solutions Ltd | Professional & scientific | 2012 |
| K.Nichols Services Ltd | Construction | 2017 |
| K1 Security ( Southwest) Ltd | Administrative & support | 2019 |
| K1 Security Solutions (SW) Ltd | Administrative & support | 2023 |
| KA Body and Paint Repairs Ltd | Wholesale & retail | 2025 |
| Kablamo Limited | Wholesale & retail | 2010 |
| Kando Mech ENG Limited | Manufacturing | 2010 |
| Kasim Construction Limited | Construction | 2024 |
| Katie Bennett Ltd | Construction | 2015 |
| Katie Hill Lettings Ltd | Households | 2022 |
| KB Machinery Limited | Manufacturing | 1994 |
| KC Servicing & Repairs Ltd | Wholesale & retail | 2026 |
| KC UK Properties Ltd | Real estate | 2018 |
| Kcimen 1 Ltd | Hospitality | 2025 |
| Keircrete Groundworks & Civils Ltd | Construction | 2025 |
| Kellands Plant (SE) Limited | Wholesale & retail | 1956 |
| Kelly Wallwork Ltd | Administrative & support | 2025 |
| KEN Marsh Limited | Construction | 2015 |
| Kenan Yummies Ltd | Hospitality | 2018 |
| Kenchington Holdings Limited | Extraterritorial | 2007 |
| Kennedy Homes Somerset Ltd | Real estate | 2025 |
| Kenneth Allsop Memorial Trust Limited | Arts & recreation | 1975 |
| Kenny and Murphy Limited | Real estate | 1984 |
| Kenwood Chef Service Limited | Other services | 2016 |
| Kenwood Manufacturing Company Limited | Wholesale & retail | 2022 |
| Kerel Ltd | Hospitality | 2024 |
| Kerrigan Construction Consultants Ltd | Professional & scientific | 2018 |
| Kersfield Developments (North Range) Limited | Construction | 2017 |
| Kevin P Johnson Limited | Construction | 2019 |
| KEW Access Ltd | Construction | 2019 |
| Key Industrial Units Ltd | Real estate | 2022 |
| Keynsham Stop Shop Limited | Wholesale & retail | 2025 |
| Keysham Mini Market Limited | Wholesale & retail | 2024 |
| Keystone Property Reports Limited | Real estate | 2012 |
| Kilbride Properties Limited | Real estate | 2023 |
| Killerbee Pole Ltd | Arts & recreation | 2023 |
| Kilve Events Limited | Arts & recreation | 2024 |
| Kindred Care Limited | Health & social care | 2015 |
| King Pies Limited | Extraterritorial | 2012 |
| King's Pasties Limited | Extraterritorial | 2010 |
| Kingdom Scaffolding Ltd | Construction | 2017 |
| Kingfisher Film Studios Limited | Information & communication | 2020 |
| Kings Lane Management Limited | Households | 2024 |
| Kingslake Recovery Limited | Wholesale & retail | 2021 |
| Kingsmoor Land Ltd | Real estate | 2023 |
| Kitchen @ Quantock Lakes Limited | Hospitality | 2020 |
| Kitchen of Fresh UK Ltd | Hospitality | 2022 |
| Kitt Limited | Wholesale & retail | 2001 |
| Kitten Finance Limited | Real estate | 1988 |
| KJH Project Consulting UK Limited | Construction | 2025 |
| KK Agencies Limited | Wholesale & retail | 2013 |
| KK Alara Ltd | Hospitality | 2026 |
| Kleen Kutt Limited | Agriculture & fishing | 2005 |
| KM Marketing Experts Ltd | Wholesale & retail | 2014 |
| KM Security Services Ltd | Other services | 2017 |
| KMA Electrical Ltd | Construction | 2024 |
| KMC Mortgage Solutions Limited | Financial services | 2005 |
| KMH Property Maintenance Ltd | Construction | 2024 |
| KMR Aesthetics Ltd | Other services | 2026 |
| Knightsbridge Stone Ltd | Professional & scientific | 2022 |
| Knot & Co. Ltd | Administrative & support | 2024 |
| Kobie Properties Limited | Real estate | 2018 |
| Kraft Brighton Ltd | Hospitality | 2026 |
| Kraft Lewisham Ltd | Wholesale & retail | 2025 |
| Kraft Stratford Ltd | Hospitality | 2026 |
| Kraven Property Limited | Households | 2023 |
| Kreupasanam Jobin Limited | Health & social care | 2026 |
| KRG Commercial Repairs Ltd | Wholesale & retail | 2024 |
| KRG Transport Ltd | Transport & logistics | 2001 |
| Krstn Ltd | Construction | 2018 |
| Krysteline Eneco Limited | Wholesale & retail | 1999 |