| Infinity Teaching Ltd | Penarth | 2013 |
| Infinity Training Services {UK} Ltd. | Birmingham | 2018 |
| Infinity Tuition Limited | Wolverhampton | 2013 |
| Infinity Tutors Ltd | Wimborne | 2025 |
| Infinity Wellbeing CIC | Bradford | 2025 |
| Infinity Yachting Limited | Devizes | 2020 |
| INFINTRA360 Limited | London | 2017 |
| Inflate Education Limited | London | 2024 |
| Inflextion Point CIC | London | 2026 |
| Inflo Studio (Oxfordshire) Limited | Newbury | 2025 |
| Inflomax Ltd | Poole | 2025 |
| Inflou Hub Ltd | London | 2026 |
| Influcate Ltd | Bury St. Edmunds | 2024 |
| Influence to Income Ltd | London | 2025 |
| Influential English Ltd | London | 2015 |
| Influential Vision Ltd | Leighton Buzzard | 2022 |
| Info Knights BPO Ltd | Wolverhampton | 2026 |
| Info-Gate Direct Ltd | Ellesmere Port | 2011 |
| Infocross Limited | Burnham-On-Sea | 1996 |
| Infofairy Ltd | Nottingham | 2018 |
| Infomedica Limited | Wigan | 2015 |
| Inforens Global Ltd | London | 2022 |
| Inform Learning Ltd | Brackley | 2017 |
| Informatics Education UK Limited | Cardiff | 2006 |
| Information Handyman Ltd | London | 2023 |
| Information Systems Examinations Board Limited | Swindon | 1990 |
| Informcomm Limited | Milton Keynes | 2008 |
| Informed Collective CIC | London | 2025 |
| Informed Patient Online Limited | West Drayton | 2025 |
| Informed Safeguarding Ltd | Swindon | 2025 |
| Infosec Assessments Ltd | Christchurch | 2024 |
| Infosecace Limited | Bournemouth | 2025 |
| Infound CIC | Wolverhampton | 2024 |
| Infoworld Ltd | London | 2025 |
| Infrabook Limited | London | 2010 |
| Infrastructure Training Services Limited | Stonebridge | 2004 |
| Infrateach Limited | London | 2010 |
| Infusion Dance Ltd | Bonnybridge | 2025 |
| Infusion DC Ltd | Bishopton | 2023 |
| ING Tutoring Ltd | Birmingham | 2024 |
| Inga PMU Academy Ltd | London | 2021 |
| Ingage Training Ltd | Waltham Abbey | 2024 |
| Ingear Holiday Clubs Limited | Leeds | 2023 |
| Ingenio Education Limited | Nottingham | 2017 |
| Ingenious Education Limited | Ilford | 2022 |
| Ingenious Learning Ltd | Leicester | 2016 |
| Ingenium Wound Consultancy Limited | Ellesmere Port | 2006 |
| Ingeniusly Ltd | London | 2022 |
| Ingenuity Education Ltd | Leeds | 2026 |
| Ingenuity Tutoring Limited | Romford | 2020 |
| Ingham-Lee Enterprises PTY Limited | Weybridge | 2021 |
| Ingiltere Kahramanmaraslilar Egitim VE Kultur Dernegi Ltd | London | 2018 |
| Ingiltere Tavla Koyu Sosyal Dayanisma Dernegi Community Interest Company | Enfield | 2018 |
| Ingla Ltd | Turnpike Lane | 2016 |
| Ingleholme Education Services Ltd | Liverpool | 2016 |
| INGLES2DAY Ltd | Ruislip | 2025 |
| INGLES4U Limited | Peacehaven | 2025 |
| Inglés CON Matt Ltd | Wirral | 2022 |
| Ingold Limited | London | 2019 |
| Ingrade Ltd | London | 2025 |
| Ingrained Limited | Kenley | 2017 |
| Ingram Lacey Education Ltd | Leeds | 2018 |
| Ingram School Business Management Ltd | Wigan | 2021 |
| Ingress Training Limited | Bexley | 2021 |
| Ingrid Gipson Ltd | Polegate | 2025 |
| Inhale Anaesthesia Ltd | Llanelli | 2026 |
| Inhana Education Ltd | Welwyn Garden City | 2024 |
| Inherit Skills Limited | Loughborough | 2017 |
| Inhive Global Limited | London | 2012 |
| Inhoco Careers Limited | Congleton | 2024 |
| Inhousew Limited | Cheltenham | 2020 |
| Inicio Education Ltd | Warrington | 2024 |
| Inicio Tutors Ltd | Market Harborough | 2012 |
| Inico Learning and Development Ltd | Shrewsbury | 2024 |
| Inita | Sunderland | 2007 |
| Initial D Ltd | Tamworth | 2022 |
| Initial Education Limited | Sheffield | 2016 |
| Initial Plant Training Ltd | Barnsley | 2019 |
| Initial Steps Ltd | Bracknell | 2014 |
| Initiate Theatre Ltd | Preston | 2018 |
| Initiative Earth | London | 2020 |
| Initiative for Conscious AI CIC | Ascot | 2025 |
| Initiatives for Regional and International Development | Wolverhampton | 2019 |
| Initio Learning Trust | Wimborne | 2014 |
| Initium Education Ltd | Newark | 2024 |
| INJ Associates Ltd | Sunderland | 2011 |
| Injectors Initiative Ltd | Watford | 2026 |
| Injs Consulting Limited | London | 2023 |
| Injury Mechanics Health & Well-Being Services Ltd | Leyland | 2023 |
| Injury Smart Training Academy Ltd | Hampton | 2025 |
| INK Academy Limited | Guildford | 2016 |
| INK and Laser Ltd | Abbots Langley | 2026 |
| INK and Scribbles Limited | Caldicot | 2022 |
| INK and Soul C.I.C. | Rossendale | 2025 |
| INK IT Right PMU Training Ltd | Cambridge | 2024 |
| INK Magic Creations Ltd | London | 2024 |
| Ink&Hairacademy Limited | Borehamwood | 2025 |
| Inkahoots! CIC | Scarborough | 2023 |
| Inker Consulting Limited | Marlow | 2007 |
| Inkerman Leisure Limited | Birmingham | 2004 |