| JSH Studio Ltd | Wholesale & retail | 2023 |
| JSN Training Limited | Other services | 2022 |
| JSS Doncaster Limited | Wholesale & retail | 2012 |
| JST Brokers Limited | Financial services | 2023 |
| JST Transport (Sheffield) Ltd | Transport & logistics | 2010 |
| JST Used Motor Spares Limited | Wholesale & retail | 2023 |
| Jsuprisehealthcare Limited | Health & social care | 2025 |
| JT Architecture Ltd | Construction | 2015 |
| JT Assessments Limited | Education | 2025 |
| JT Car Sales Limited | Wholesale & retail | 2021 |
| JT Elec & Solar Ltd | Construction | 2026 |
| JT Pierpoint Utilities Ltd | Construction | 2024 |
| JT Property (Yorkshire) Limited | Real estate | 2022 |
| Jtmt Engineering Limited | Professional & scientific | 2022 |
| JTN Solutions Limited | Construction | 2023 |
| Jubilee Care Home Limited | Health & social care | 2019 |
| Jucaria Drivers Limited | Transport & logistics | 2017 |
| Juice Junkies Ltd | Hospitality | 2025 |
| Juiceworld-Uk Ltd | Manufacturing | 2025 |
| Jules Martin Consulting Ltd | Professional & scientific | 2015 |
| Juliana's Shop Limited | Wholesale & retail | 2021 |
| Julie Woodhams Limited | Wholesale & retail | 2013 |
| Jumbo Building Systems Limited | Construction | 2003 |
| Jumper Trans Ltd | Transport & logistics | 2018 |
| JUN Q Properties Ltd | Real estate | 2018 |
| Junction 1 Storage Ltd | Administrative & support | 2016 |
| Junction 31 Truck Wash Ltd | Transport & logistics | 2025 |
| Junction 34 Cars Ltd | Wholesale & retail | 2020 |
| Junction 36 Ltd | Professional & scientific | 2013 |
| Jung Iqed Ltd | Information & communication | 2019 |
| Junksterz Ltd | Wholesale & retail | 2021 |
| JUPETER61 Ltd | Administrative & support | 2017 |
| Juraj Sveda Transport Limited | Transport & logistics | 2014 |
| Just 4 Success Limited | Construction | 2017 |
| Just Cars and Commercials Ltd | Wholesale & retail | 2022 |
| Just DAN Accounting Limited | Professional & scientific | 2025 |
| Just Dance Studios (Chapeltown) Limited | Administrative & support | 2018 |
| Just Dance Studios Limited | Administrative & support | 2015 |
| Just for YOU Photography (SY) Limited | Professional & scientific | 2012 |
| Just Molt Ltd | Professional & scientific | 2019 |
| Just Wicks Limited | Wholesale & retail | 2021 |
| Just-Boilers Nationwide Ltd | Construction | 2017 |
| Justica Limited | Real estate | 2024 |
| Justobe Limited | Professional & scientific | 2021 |
| Juton Logistics Limited | Transport & logistics | 2016 |
| Jutrzenka Limited | Transport & logistics | 2023 |
| JV Rich Ltd | Construction | 2023 |
| JW DRY Lining Ltd | Construction | 2024 |
| JW Mortgage Services Ltd | Financial services | 2013 |
| JW Roofing & Renewables Limited | Construction | 2024 |
| JW Speed Ltd | Manufacturing | 2020 |
| JW Studio Limited | Arts & recreation | 2019 |
| JZ Projects Limited | Professional & scientific | 2022 |
| JZ Property Limited | Construction | 2021 |
| K & C Fabrications Ltd | Manufacturing | 2013 |
| K & D Singh Limited | Wholesale & retail | 2014 |
| K & H Travel Ltd | Administrative & support | 2008 |
| K & K Planning and Building Consultancy Ltd | Construction | 2024 |
| K & N Holdings Rotherham Limited | Real estate | 2025 |
| K & R Footcare Services Ltd | Health & social care | 2018 |
| K B S (Sheffield) Ltd | Wholesale & retail | 2009 |
| K D Optics Design & Engineering Limited | Manufacturing | 2011 |
| K Designs Services Ltd | Professional & scientific | 2025 |
| K Egan Drywall Limited | Construction | 2023 |
| K H Property Group Limited | Real estate | 2015 |
| K Packaging Ltd. | Wholesale & retail | 2010 |
| K R Plastering Ltd | Construction | 2025 |
| K Richardson & Family Holdings Limited | Financial services | 2025 |
| K Richardson Construction Ltd | Construction | 2025 |
| K S Wright Properties Ltd | Real estate | 2020 |
| K Thomas Longden Ltd | Construction | 2024 |
| K Westwood Ltd | Information & communication | 2015 |
| K&H Autos Limited | Wholesale & retail | 2020 |
| K&M Dream Property Investment Ltd | Real estate | 2026 |
| K&O Enterprise Ltd | Hospitality | 2025 |
| K. Wright Consultants Ltd | Construction | 2024 |
| K.D.S. Construction Company Limited | Construction | 1976 |
| K.J.Laver Ltd | Public administration | 2023 |
| K.R Independent Change Management Consultancy Ltd | Professional & scientific | 2020 |
| K2 Roofing and Design Limited | Construction | 2006 |
| KA Nova Ltd | Financial services | 2025 |
| Kabe Consulting Limited | Professional & scientific | 2014 |
| Kabe Studio Ltd | Manufacturing | 2016 |
| Kadmilos Limited | Wholesale & retail | 2021 |
| Kaespace Ltd | Real estate | 2025 |
| KAH Premier Medical Services Limited | Health & social care | 2026 |
| Kahindi Limited | Health & social care | 2023 |
| Kakar Recruitment Ltd | Administrative & support | 2013 |
| Kalapura Limited | Health & social care | 2021 |
| Kalki AI Universe Group Ltd | Information & communication | 2026 |
| Kall Tools Limited | Financial services | 2025 |
| Kalonji Doors Limited | Construction | 2021 |
| KAM Cars Ltd | Wholesale & retail | 2020 |
| KAM Logistics Services Limited | Transport & logistics | 2023 |
| Kamran Razzaq & Company Limited | Transport & logistics | 2026 |
| Kancelaria Ultimatum Ltd | Administrative & support | 2015 |
| Kannamundayil Ltd | Health & social care | 2024 |
| Kaplings Ltd | Real estate | 2018 |
| Karbon Kitchen & Bar Limited | Hospitality | 2025 |
| Karen Etheridge Wealth Management Ltd | Financial services | 2012 |