| Indian Bites Co. Ltd | Hospitality | 2025 |
| Individual Private Solutions Ltd | Professional & scientific | 2020 |
| Indumeni Investments (UK) Limited | Real estate | 2021 |
| Infinite Degree Ltd | Information & communication | 2009 |
| Infinite Global Recruitment Ltd | Professional & scientific | 2025 |
| Info Server Consulting Ltd | Information & communication | 1998 |
| Inform Brickwork Ltd | Construction | 2024 |
| Informme Ltd | Professional & scientific | 2018 |
| Inglis Group Ltd | Professional & scientific | 2024 |
| Inktransient Ltd. | Wholesale & retail | 2025 |
| Inlife Advisory Ltd | Professional & scientific | 2024 |
| Innotec Solutions Ltd. | Wholesale & retail | 2014 |
| Innotech Technology & Innovative Solution Ltd | Information & communication | 2024 |
| Innovation Leisure Manchester Limited | Arts & recreation | 2016 |
| Inside Rugby Limited | Arts & recreation | 2001 |
| Insight Design (UK) Limited | Professional & scientific | 1998 |
| Insite P & C Ltd | Real estate | 2023 |
| INSPIRED2 Limited | Professional & scientific | 2008 |
| Integrated Airport Solutions Ltd | Professional & scientific | 2009 |
| Integrative Enneagram Solutions Limited | Education | 2017 |
| International Creative Technologies Ltd | Mining & quarrying | 2012 |
| Interpretation Solutions Ltd | Professional & scientific | 2018 |
| Interskin Ltd | Other services | 2025 |
| Interview & YOU Ltd | Education | 2024 |
| Into Interiors Ltd | Wholesale & retail | 2020 |
| Into Risk Ltd | Professional & scientific | 2008 |
| Introversion Software Holdings Limited | Financial services | 2018 |
| Invision Cyber Limited | Financial services | 2026 |
| IPS G M Ltd | Administrative & support | 2023 |
| Iron Dome Ltd | Administrative & support | 2017 |
| IRP Properties Ltd | Real estate | 2025 |
| Isafe Gadgets Ltd | Wholesale & retail | 2022 |
| Isha Pavel Ltd | Wholesale & retail | 2011 |
| IT Surrey Ltd | Information & communication | 2017 |
| Itcan Ltd | Administrative & support | 2019 |
| ITL Associates Ltd | Professional & scientific | 2026 |
| Ivory Gardenia Ltd | Administrative & support | 2018 |
| Izko Limited | Wholesale & retail | 2003 |
| J & C Richardson Ltd | Manufacturing | 2024 |
| J & J Bakery Ltd | Transport & logistics | 2009 |
| J & J Services Southern Ltd | Administrative & support | 2018 |
| J & S Developments Ltd | Real estate | 2019 |
| J L Miro Limited | Professional & scientific | 2017 |
| J W a Event Management Limited | Professional & scientific | 2006 |
| J&P Global UK Ltd | Real estate | 2019 |
| J.E.N Futures Trading Ltd | Financial services | 2026 |
| JAB Consultancy Ltd | Professional & scientific | 2025 |
| JAC Resources Limited | Other services | 2018 |
| Jack Lord Ltd | Information & communication | 2021 |
| Jack Wayne Fitness Limited | Arts & recreation | 2023 |
| Jackers.Co.Uk. Limited | Administrative & support | 2000 |
| Jadara Innovations Ltd | Information & communication | 2023 |
| Jade Property Investors Ltd | Real estate | 2019 |
| Jags Studios Ltd | Other services | 2022 |
| Jakem Ltd | Real estate | 2024 |
| Jaurah Ltd | Wholesale & retail | 2024 |
| Javelyn Limited | Administrative & support | 2014 |
| Jaynefish Limited | Information & communication | 2025 |
| JB Consulting Limited | Professional & scientific | 2023 |
| JC Aviation Consultancies Ltd | Professional & scientific | 2021 |
| Jcfern Medical Ltd | Health & social care | 2020 |
| Jcmk Limited | Professional & scientific | 2001 |
| JCR Jones Ltd | Information & communication | 2018 |
| JDJ Enterprise Risk Management Services Ltd | Professional & scientific | 2018 |
| JDM Printing Limited | Manufacturing | 2026 |
| Jefferson Enterprises Limited | Professional & scientific | 2015 |
| Jeluna Properties Limited | Real estate | 2007 |
| Jenloupa Ltd | Wholesale & retail | 2014 |
| Jennyreynoldstravel Ltd | Administrative & support | 2025 |
| Jetvine Consultancy Ltd | Professional & scientific | 2020 |
| Jfry Consulting Limited | Professional & scientific | 2026 |
| Jguru Ltd | Financial services | 2018 |
| Jhcclivingthedream Ltd | Administrative & support | 2026 |
| JIA Homes Limited | Real estate | 2019 |
| JM Property Investing Ltd | Real estate | 2024 |
| JMH Ideas Ltd | Wholesale & retail | 2012 |
| Joe's Garden Solutions Limited | Administrative & support | 2026 |
| John Hilden Properties Ltd | Real estate | 2023 |
| Jomaral Ltd | Wholesale & retail | 2025 |
| JON Holmes Media Limited | Administrative & support | 2006 |
| Josephjames Carpentry and Building Services Ltd | Construction | 2018 |
| Joyce & Stan Limited | Construction | 2017 |
| Joys of Vintage Ltd | Wholesale & retail | 2025 |
| Jrmp CAD Services Ltd | Professional & scientific | 2007 |
| JT Building Renovations Ltd | Construction | 2025 |
| Jtim Investment Company Ltd | Financial services | 2025 |
| Jula Investments Limited | Real estate | 2018 |
| Jump Social Ltd | Professional & scientific | 2017 |
| Justmax Ltd | Hospitality | 2019 |
| K & B Ventures Ltd | Wholesale & retail | 2023 |
| K & L Infinity Ltd | Hospitality | 2019 |
| K C Pipe Installations Limited | Manufacturing | 2014 |
| K M Vital Logistics Ltd | Transport & logistics | 2021 |
| K Tour Ltd | Administrative & support | 2023 |
| KAI Films Limited | Professional & scientific | 2026 |
| KAI Limit Limited | Arts & recreation | 2026 |
| Kaia Wellness Salon Ltd | Other services | 2026 |
| Kaisor Marketing Ltd | Professional & scientific | 2014 |
| Kalaja E Dodes Ltd | Construction | 2021 |
| Kaminski Plumbing Limited | Construction | 2017 |