| John&Mary Haulage Ltd | Transport & logistics | 2023 |
| John-Paul International Ltd | Information & communication | 2019 |
| Johnson Waste Limited | Water & waste | 2026 |
| Johnston Strategic Finance Ltd | Professional & scientific | 2026 |
| Johnston Wagstaffe & Co Ltd | Manufacturing | 2015 |
| Johnstone Solutions Ltd | Wholesale & retail | 2022 |
| JOI Social Care Ltd | Health & social care | 2026 |
| Joice and Hill Poultry Ltd | Agriculture & fishing | 1964 |
| Join US Ltd | Other services | 2013 |
| Joinery Design Services Ltd | Professional & scientific | 2002 |
| Jojo Property Services Ltd | Administrative & support | 2024 |
| Jojoestore Limited | Wholesale & retail | 2024 |
| Joliam Limited | Real estate | 2020 |
| Jollka Ltd | Transport & logistics | 2018 |
| JON Wholesale Ltd | Wholesale & retail | 2024 |
| Jonathan & Maloya Co. Ltd | Wholesale & retail | 2025 |
| Jonathan Edwards Limited | Financial services | 2009 |
| Jonathan Haslam Ltd | Real estate | 2024 |
| Jondan Group Ltd | Wholesale & retail | 2025 |
| Jonels Property Venture Ltd | Real estate | 2026 |
| Jones & Jones Limited | Agriculture & fishing | 1948 |
| Jones Installations Windows and Doors Ltd | Construction | 2026 |
| Jonwol Limited | Health & social care | 2022 |
| Joovee Services Ltd | Wholesale & retail | 2013 |
| Jordan and Co Financial Services Ltd | Financial services | 2023 |
| Jordan's World Limited | Administrative & support | 2024 |
| Jorea Clinic Ltd | Health & social care | 2026 |
| Jorge Delivery Ltd | Transport & logistics | 2019 |
| Jorvinci Group Limited | Wholesale & retail | 2021 |
| Jorvinci Ltd | Wholesale & retail | 2018 |
| Josben International College UK Ltd | Information & communication | 2019 |
| Jose Bernaza Limited | Health & social care | 2018 |
| Joseph Construction ST Neots Limited | Construction | 2012 |
| Joseph Creative Business Limited | Professional & scientific | 2015 |
| Joseph Flach & Sons Limited | Wholesale & retail | 1927 |
| Joseph Hill Consultancy Services Ltd | Professional & scientific | 2014 |
| Joseph Holdings (Peterborough) Limited | Financial services | 2021 |
| Joseph Properties & Developments Ltd | Real estate | 2022 |
| Josh Transport Ltd | Transport & logistics | 2025 |
| Joshdel Projects Ltd | Professional & scientific | 2016 |
| Joshua Stevens Limited | Construction | 2016 |
| Jotharv Properties Ltd | Households | 2025 |
| Jotobo Ltd | Real estate | 2024 |
| Jowi Transport Ltd | Transport & logistics | 2019 |
| Joy at Home Ltd | Wholesale & retail | 2026 |
| Joy Development Limited | Real estate | 2016 |
| Joy Titilayo Foundation | Public administration | 2021 |
| Joyce and Spires Limited | Arts & recreation | 2011 |
| Joydrive Couriers Ltd | Transport & logistics | 2026 |
| Joymeriam Care Limited | Other services | 2017 |
| Jozrys Ltd. | Transport & logistics | 2016 |
| JP & Sons (Consultancy) Ltd | Health & social care | 2019 |
| JP 0424 Ltd | Manufacturing | 2024 |
| JP Butcher Ltd | Wholesale & retail | 2023 |
| JP Dentique Limited | Health & social care | 2008 |
| JP Financial Solutions 2016 Ltd | Financial services | 2016 |
| JP Howarth Ltd | Professional & scientific | 2022 |
| JP Interwebified Ltd | Professional & scientific | 2012 |
| JP Wyles Construction Ltd | Construction | 2025 |
| Jp&G Group Ltd | Public administration | 2018 |
| JPB Signs Ltd | Manufacturing | 2020 |
| JPD Transport Solutions Ltd | Transport & logistics | 2015 |
| JPF Designs Limited | Professional & scientific | 2021 |
| JPF Home Improvement Ltd | Construction | 2018 |
| JPK (Peterborough) Limited | Professional & scientific | 2019 |
| JPM Meats UK Limited | Wholesale & retail | 2021 |
| JPM Mechanical Design Limited | Professional & scientific | 2019 |
| JPN Project Management Limited | Professional & scientific | 2019 |
| JPN Projects Limited | Real estate | 2002 |
| JPR Cloud Analytics Limited | Information & communication | 2019 |
| JPR Graphics and Design Limited | Professional & scientific | 2003 |
| Jptf Services Limited | Manufacturing | 2011 |
| JR Food Express Peterborough Ltd | Wholesale & retail | 2024 |
| JR Property & Maintenance Ltd | Real estate | 2022 |
| JRB Consultancy Ltd | Information & communication | 2008 |
| JRG Mortgage & Protection Solutions Ltd | Financial services | 2024 |
| JRH Cleaning Limited | Administrative & support | 2018 |
| JRL Investments Ltd | Professional & scientific | 2011 |
| JRL Property Group Ltd | Construction | 2026 |
| JRM Coaching Academy Limited | Education | 2025 |
| JRN Property Investments Ltd | Real estate | 2020 |
| Jrnv Properties Ltd | Real estate | 2024 |
| JRR Fire & Security Ltd | Construction | 2024 |
| JRS Carpentry Limited | Construction | 2020 |
| JRS Solutions Holdings Limited | Financial services | 2022 |
| JRS Solutions Limited | Administrative & support | 2016 |
| JRY Transport Ltd | Transport & logistics | 2024 |
| JS ENG Limited | Manufacturing | 2025 |
| JS Lloyds Properties Limited | Real estate | 2025 |
| JS Motors GmbH Ltd | Professional & scientific | 2026 |
| JS Solutions ICT Limited | Information & communication | 2018 |
| Js&Jk UK1 Limited | Real estate | 2025 |
| JSB Energy Solutions Ltd | Professional & scientific | 2025 |
| JSB Tech Ltd | Professional & scientific | 2015 |
| JSD Asset Management Ltd | Real estate | 2019 |
| Jsdk Properties Limited | Real estate | 2021 |
| JSH Consultancy Ltd | Information & communication | 2014 |
| JSL Coaching Ltd | Administrative & support | 2025 |
| Jsl-Lpl LLP | | 2010 |
| JSM Group Limited | Administrative & support | 2018 |