| Inmoment Limited | Information & communication | 1981 |
| Inmomentum Limited | Transport & logistics | 2004 |
| Innana.World Ltd | Extraterritorial | 2025 |
| Innate Dating Ltd | Information & communication | 2025 |
| Innateq Limited | Manufacturing | 2005 |
| Innc Ltd | Construction | 2025 |
| Inner Circle DJS Limited | Administrative & support | 2006 |
| Inner Creative Ltd | Extraterritorial | 2021 |
| Inner Designs Ltd | Construction | 2016 |
| Inner Fire Limited | Hospitality | 2018 |
| Inner Gym CIC | Health & social care | 2025 |
| Inner Harmony Clinic Ltd | Health & social care | 2025 |
| Inner Perspective Limited | Health & social care | 2026 |
| Inner Sanctuary Productions Limited | Information & communication | 2022 |
| Inner Scene Studios Limited | Information & communication | 2025 |
| Inner-Awakening Ltd | Extraterritorial | 2022 |
| Innere Logistic's Limited | Construction | 2015 |
| Innerspaces Self Storage Limited | Real estate | 2009 |
| Innervate Therapeutics Ltd | Professional & scientific | 2019 |
| Innes Wilkin Architecture Limited | Professional & scientific | 2015 |
| Innishmore Group Limited | Households | 2026 |
| Innlove Limited | Hospitality | 2013 |
| Innohvera Ltd | Professional & scientific | 2025 |
| Innoideas Limited | Information & communication | 1998 |
| Innopulse Environmental Ltd | Professional & scientific | 2016 |
| Innopulse Ltd | Professional & scientific | 2022 |
| Innotech Partners Limited | Administrative & support | 2020 |
| INNOV8 Decorating Solutions Ltd | Construction | 2023 |
| Innova Property Cornwall Ltd | Hospitality | 2020 |
| Innova Property Investments Ltd | Real estate | 2021 |
| Innova Property Trading Ltd | Real estate | 2024 |
| Innovar Limited | Professional & scientific | 2024 |
| Innovate Awarding Ltd | Education | 2010 |
| Innovate Bioconsulting Ltd | Professional & scientific | 2025 |
| Innovate IT Ltd | Information & communication | 2003 |
| Innovate Talent Solutions Ltd | Professional & scientific | 2025 |
| Innovatewild Ltd | Information & communication | 2018 |
| Innovatex Recruiters Ltd | Administrative & support | 2024 |
| Innovatexlabs Ltd | Wholesale & retail | 2025 |
| Innovation Frames Ltd | Professional & scientific | 2024 |
| Innovation Hairdressing Ltd | Other services | 2024 |
| Innovation Rehab Limited | Manufacturing | 2005 |
| Innovation Renovations (Bristol) Ltd | Construction | 2025 |
| Innovative Coaching Consultancy Limited | Other services | 2014 |
| Innovative Epoxy Solutions Limited | Wholesale & retail | 1999 |
| Innovative International Consultants Ltd | Professional & scientific | 2024 |
| Innovative Training Ltd | Education | 2018 |
| Innovecom Solutions Limited | Information & communication | 1997 |
| Innovex Management Limited | Information & communication | 1994 |
| Innovia Wealth Management Ltd | Financial services | 2024 |
| Inochi Longevity Limited | Health & social care | 2024 |
| Inooprime Ltd | Transport & logistics | 2025 |
| INOV8 Studios Ltd | Information & communication | 2019 |
| Inox Projects UK Ltd | Construction | 2025 |
| Inperspective (UK) Ltd | Education | 2003 |
| Inpowered Limited | Information & communication | 2012 |
| Inqvine Ltd | Information & communication | 2020 |
| Inretail Group Ltd | Manufacturing | 2017 |
| INS Transport Ltd | Manufacturing | 2020 |
| Inscape Commercial Properties UK Ltd | Real estate | 2020 |
| Inscripto Ltd | Arts & recreation | 2024 |
| Insemigen Ltd | Agriculture & fishing | 2023 |
| Insero Limited | Information & communication | 2011 |
| Insert Music Here Ltd | Wholesale & retail | 2026 |
| Inshore Marine Limited | Transport & logistics | 2023 |
| Inside Line Solutions Ltd | Professional & scientific | 2025 |
| Inside Properties Limited | Construction | 2017 |
| Inside the Pocket Limited | Information & communication | 2020 |
| Inside Travel Group Limited | Administrative & support | 2000 |
| Insideasia Tours Ltd | Extraterritorial | 2019 |
| Insidejapan Tours Limited | Extraterritorial | 2019 |
| Insideout Facilities Ltd | Administrative & support | 2024 |
| Insideout Worx Ltd | Other services | 2014 |
| Insidetravel Technology Ltd | Extraterritorial | 2016 |
| Insight Business Strategies Ltd. | Professional & scientific | 1998 |
| Insight Centric Limited | Professional & scientific | 2025 |
| Insight Cycles Ltd | Wholesale & retail | 2020 |
| Insight Display Bristol Ltd | Manufacturing | 2024 |
| Insight Media Group Ltd | Information & communication | 2018 |
| Insight Neuropsychology Consulting Ltd | Health & social care | 2026 |
| Insight Specialist Spaces Limited | Construction | 2017 |
| Insnovo Ltd | Wholesale & retail | 2020 |
| Insourcy Ltd. | Hospitality | 2023 |
| Inspacial (East Street) Limited | Construction | 2022 |
| Inspacial Management Limited | Real estate | 2025 |
| Inspect 2 Protect Ltd | Extraterritorial | 2020 |
| Inspection Management Limited | Professional & scientific | 2007 |
| Insphere Ltd | Professional & scientific | 2013 |
| Inspiir Ltd | Arts & recreation | 2022 |
| Inspiral Pathways Ltd | Professional & scientific | 2015 |
| Inspiraling Stair Systems Ltd | Manufacturing | 2026 |
| Inspirasphere Ltd | Education | 2019 |
| Inspiration Exhibitions Limited | Manufacturing | 1997 |
| Inspirational Dynamics Ltd | Information & communication | 2014 |
| Inspire Construction Ltd | Construction | 2020 |
| Inspire Editing Limited | Information & communication | 2019 |
| Inspire Hair Technology Limited | Other services | 2014 |
| Inspire Invester Estates Limited | Real estate | 2025 |
| Inspire M Services Ltd | Health & social care | 2025 |
| Inspire Science Limited | Administrative & support | 2011 |