| JCK Safety Solutions Limited | Manufacturing | 2017 |
| JCS Clean Solutions Ltd | Administrative & support | 2025 |
| JD Services 2013 Limited | Information & communication | 2013 |
| JDC (Wirral) Limited | Wholesale & retail | 2026 |
| Jeetoe Ltd | Hospitality | 2026 |
| JEN Environmental Limited | Professional & scientific | 2022 |
| Jenkins Properties Limited | Real estate | 2019 |
| Jenny Fewtrell Ltd | Health & social care | 2024 |
| Jeppstones Consultancy Limited | Information & communication | 2017 |
| JGC Electrical Contracts Ltd | Construction | 2024 |
| Jimmy FC Limited | Hospitality | 2025 |
| Jishop Software Limited | Information & communication | 2018 |
| Jjkpn Ltd | Administrative & support | 2025 |
| JJM Engineering Solutions Limited | Professional & scientific | 2018 |
| Jjmtec Ltd | Professional & scientific | 2012 |
| Jjrobinson Ltd | Construction | 2025 |
| JKH Solutions Limited | Administrative & support | 2025 |
| JLD Change Management Ltd | Health & social care | 2022 |
| JLM Management Ltd | Households | 2025 |
| JM & WH Properties Limited | Real estate | 2025 |
| JMA Plumbing and Heating Ltd | Construction | 2020 |
| JMS Construction (Slough) Ltd | Construction | 2025 |
| JMS Property Developments Limited | Construction | 2019 |
| JOE Burchill Consultancy Ltd | Transport & logistics | 2018 |
| Joes Taxis Ltd | Transport & logistics | 2024 |
| John Carrington Limited | Wholesale & retail | 2006 |
| John Gillan Property Group Ltd | Construction | 2025 |
| John Harrickie Ltd | Manufacturing | 2026 |
| John Randles Paints Ltd | Construction | 2018 |
| Johnson Group Property Ltd | Real estate | 2024 |
| Joistz Ltd | Wholesale & retail | 2019 |
| Jomartin Ltd | Hospitality | 2017 |
| Jonathan Benson Fine Art Ltd | Construction | 2024 |
| Jones & Baker Property Ltd | Real estate | 2024 |
| Jordan Elec Ltd | Construction | 2025 |
| JPF Property Management Limited | Real estate | 2016 |
| JRC Training Limited | Education | 2015 |
| JS Construction Wirral Ltd | Construction | 2020 |
| JS Groundworks Wirral Ltd | Construction | 2022 |
| JS Structural Wirral Limited | Construction | 2025 |
| JSG Trading Limited | Wholesale & retail | 2012 |
| Jskp Ltd | Real estate | 2022 |
| Jslt Ltd | Construction | 2020 |
| Jubilee Church Wirral Ltd | Other services | 2012 |
| Jubilee Medical Ltd | Health & social care | 2022 |
| Julia ANN B Ltd | Construction | 2025 |
| Julu Stores Ltd | Wholesale & retail | 2023 |
| Junglepadel Ltd | Arts & recreation | 2025 |
| Juni Express XIX Limited | Wholesale & retail | 2024 |
| Just Click Marketing Limited | Administrative & support | 2023 |
| Just Doors [NW] Ltd | Manufacturing | 2020 |
| Just Go Glow Ltd | Information & communication | 2026 |
| Just Wright Partnership Ltd | Professional & scientific | 2025 |
| Justin Dooley Consulting Limited | Administrative & support | 2024 |
| JW Finance Employee Benefits Ltd | Extraterritorial | 2023 |
| JW Finance Ltd | Financial services | 2007 |
| JWE Solutions Ltd | Administrative & support | 2020 |
| K & S Mathews Ltd | Hospitality | 2023 |
| K Accountants Ltd | Professional & scientific | 2012 |
| K&C Contracts Limited | Extraterritorial | 2024 |
| K&R Property Solutions Ltd | Real estate | 2021 |
| K.B. Building & Developments Ltd | Construction | 2025 |
| K10 Groundworks Ltd | Construction | 2020 |
| K9 Daycare Ltd | Other services | 2021 |
| Kaep Ltd | Administrative & support | 2024 |
| KAM Wines Limited | Hospitality | 2014 |
| Kando Factory Limited | Information & communication | 2023 |
| Kane's Property Ltd | Real estate | 2024 |
| KAV Taverns (Newton) Ltd | Hospitality | 2025 |
| KAV Taverns (Park Brow) Ltd | Hospitality | 2025 |
| KAV Taverns (Rose and Crown) Ltd | Hospitality | 2025 |
| KAV Taverns (Spitfire) Ltd | Hospitality | 2025 |
| Kayvee Properties Limited | Real estate | 2025 |
| KAZ Logistics Ltd | Administrative & support | 2025 |
| KAZ Tranz Limited | Wholesale & retail | 2012 |
| KB Catering Ltd | Hospitality | 2026 |
| KBH Accountants Limited | Professional & scientific | 2002 |
| KBH Properties (Wirral) Limited | Real estate | 2019 |
| KCG Investments Limited | Construction | 2021 |
| Keisha-Rue PVT Ltd | Health & social care | 2022 |
| Kellwood Limited | Construction | 2011 |
| Kellwood Properties Limited | Real estate | 2018 |
| Kelma International (UK) Limited | Professional & scientific | 2005 |
| Kelstar Engineering Limited | Construction | 1992 |
| KEN Beard & SON Ltd | Construction | 2014 |
| Kenham Court Management Limited | Households | 1994 |
| Kennedy Renewable Services Ltd | Construction | 2023 |
| Kenny Data Limited | Information & communication | 2025 |
| Kenny Engineering Limited | Construction | 2007 |
| Kesuone Limited | Real estate | 2025 |
| Keystone (NW) Construction Consultancy Limited | Professional & scientific | 2026 |
| Keystone Building Contractors Limited | Construction | 2019 |
| Keyurban Property Management Limited | Households | 1989 |
| Kezu Limited | Real estate | 2025 |
| KG Electrical Limited | Manufacturing | 2021 |
| Khalla Barber Ltd | Other services | 2026 |
| KHL Properties Ltd | Construction | 2023 |
| Kiddy Comps Ltd | Extraterritorial | 2024 |
| Kiings Convenience Store Wallasey Ltd | Wholesale & retail | 2022 |
| Kindred Group Ltd | Financial services | 2018 |