| Jhedte Limited | Wholesale & retail | 2017 |
| Jiaocheng County Xinxing Casting Co., Ltd | Manufacturing | 2023 |
| Jiayi Trade Ltd | Wholesale & retail | 2024 |
| Jimmys Light Haulage Ltd | Transport & logistics | 2007 |
| JIN NIU Company Limited | Wholesale & retail | 2023 |
| JIN YUE Hong Trading Co., Ltd | Wholesale & retail | 2023 |
| Jineeentic Ltd | Wholesale & retail | 2023 |
| Jiujiang Qiyuan Mechanical Electronic Instrument Co., Ltd | Manufacturing | 2023 |
| JJ Domatriolo Limited | Information & communication | 2006 |
| JKT International Limited | Transport & logistics | 2005 |
| JLN Building Services Ltd | Construction | 2003 |
| JM1 Limited | Health & social care | 2003 |
| JMG Engineering Company (UK) Ltd | Manufacturing | 2003 |
| JML PKG Limited | Wholesale & retail | 2023 |
| Jngm Plus Trading Co., Ltd | Wholesale & retail | 2023 |
| Joannis Properties Limited | Real estate | 2000 |
| JOB Change 2007 | Other services | 2007 |
| JOE and S. Lunt Motor Holdings Limited | Real estate | 1948 |
| Joey Zhou Limited | Health & social care | 2021 |
| Johal Dairies Holding Co Limited | Real estate | 1994 |
| Johal Dairies Limited | Wholesale & retail | 1987 |
| Johal Dairies Products Limited | Professional & scientific | 1994 |
| Johal Products Limited | Professional & scientific | 1994 |
| Johal Transport GB Limited | Transport & logistics | 2007 |
| John Anthony Perkins Limited | Construction | 2005 |
| John Barrett Financial Services Limited | Administrative & support | 1996 |
| John Eccles & Co LLP | | 2001 |
| John Eccles & Co.(Blackheath)Limited | Manufacturing | 1946 |
| John Hill & Sons (Iron Founders) Limited | Manufacturing | 1947 |
| John King and Sons (Coventry) Limited | Wholesale & retail | 2005 |
| John Wilson Building Services Ltd | Construction | 2005 |
| Johnson Cooke Associates Limited | Extraterritorial | 2005 |
| Jones & Bircher Ltd | Construction | 2012 |
| Jones of Smethwick Limited | Extraterritorial | 1969 |
| Jones Springs (Engineering) Limited | Manufacturing | 1953 |
| Jopy International Limited | Manufacturing | 2023 |
| JR Machine Transport Limited | Construction | 2006 |
| JS Cholas Investments Ltd | Real estate | 2024 |
| JS Computer Consulting Limited | Information & communication | 1996 |
| JSG Solutions Limited | Professional & scientific | 2003 |
| Jubilee Investments (Willenhall) Ltd | Real estate | 2023 |
| Julian Properties (Midlands) Limited | Real estate | 1968 |
| Jumbo Digital Limited | Professional & scientific | 2003 |
| Jumbo Properties Limited | Real estate | 2005 |
| Junction 2 Interiors Limited | Wholesale & retail | 2000 |
| JW Compassionate Care Services Ltd | Hospitality | 2017 |
| JWS Erectors Limited | Wholesale & retail | 1999 |
| K & C Property Limited | Administrative & support | 1979 |
| K & J UK Limited | Hospitality | 2007 |
| K & K Fashions Limited | Manufacturing | 1998 |
| K B Engineering Supplies Limited | Manufacturing | 2002 |
| K L George (Pipework Services) Limited | Construction | 2004 |
| K L Whitehouse Associates Limited | Professional & scientific | 2003 |
| K R Roofing & Building Services Limited | Construction | 2003 |
| K. & W. Mechanical Services Limited | Manufacturing | 1980 |
| K. Daly Brickwork Limited | Construction | 2004 |
| K. Read Tail-Lifts Limited | Administrative & support | 2006 |
| K.B. Handley Plant Hire Limited | Administrative & support | 1998 |
| K.B. Interior Decorators Limited | Construction | 2002 |
| K.D. Riley Limited | Manufacturing | 2003 |
| K.E.S. Limited | Construction | 2002 |
| K.G.J. Insurance Brokers (Stourbridge) Limited | Financial services | 1969 |
| K.J. Martin Ltd | Administrative & support | 2003 |
| K.K. Mistry Pharmacy Ltd | Health & social care | 2004 |
| K.M. Rogers Limited | Construction | 2003 |
| K.P. Electrical Contractors Ltd. | Construction | 2000 |
| K.P. Young Roofing Limited | Construction | 2002 |
| Kairuiqi Machine Industry Co., Ltd | Manufacturing | 2023 |
| Kallar Consultancy Limited | Real estate | 2007 |
| Kallar Software Solutions Limited | Information & communication | 2004 |
| Kalsi Investments Limited | Real estate | 2005 |
| Kang & Mand Limited | Households | 1993 |
| Kantina 4 Ltd | Hospitality | 2023 |
| Kapella | Health & social care | 1996 |
| Kara's Pharmacy Limited | Wholesale & retail | 1991 |
| Karen Carpets Limited | Construction | 1965 |
| Karios Limited | Hospitality | 2007 |
| Karsscom Limited | Manufacturing | 2004 |
| Kashmir Sweet Centre Limited | Wholesale & retail | 2001 |
| Katesby Process Engineering Limited | Professional & scientific | 2003 |
| Kbsp Limited | Administrative & support | 2005 |
| KE XIN Technology Co., Limited | Wholesale & retail | 2023 |
| Kechuang Trading Co., Ltd | Wholesale & retail | 2023 |
| Keep KEE Trading Co., Ltd | Wholesale & retail | 2023 |
| Keith Round Limited | Administrative & support | 2000 |
| Keltruck Limited | Wholesale & retail | 1993 |
| Kent Road Construction Ltd | Construction | 2002 |
| Kerrus Properties Limited | Real estate | 2004 |
| Ketley Brick Company,Limited(The) | Manufacturing | 1961 |
| Key Performance Limited | Professional & scientific | 1999 |
| Key Service Centres Limited | Real estate | 1997 |
| Keypress Limited | Information & communication | 1997 |
| KGD Decorating Services Limited | Construction | 2004 |
| Khoja Shia Ithna-Asheri Muslim Community (Baquir) Limited | Real estate | 2007 |
| Khoja Shia Ithna-Asheri Muslim Community (Jaafery) Limited | Real estate | 2007 |
| Kids Funworld Ltd | Arts & recreation | 2006 |
| Kiku Services Limited | Information & communication | 2005 |
| Kilas Forword Limited | Wholesale & retail | 2023 |
| Kilger UK Ltd | Administrative & support | 2018 |
| Kingscroft Property Management Limited | Households | 2001 |