| 4 Friends Ltd | Nottingham | 2017 |
| 4 G Steel Stockholder Ltd | Wednesbury | 2010 |
| 4 Generations Corporation Limited | Braintree | 2020 |
| 4 Joinery Limited | London | 2022 |
| 4 Littles Ltd | London | 2025 |
| 4 Long Hair Ltd | Southport | 2016 |
| 4 Maintenance Engineering Ltd | Virginia Water | 2004 |
| 4 MW (Scotland) Ltd | Pitlochry | 2022 |
| 4 Packaging Solutions Limited | Selby | 2004 |
| 4 Precision Ltd | London | 2021 |
| 4 Print Limited | Epsom | 1980 |
| 4 Seasons (Wembley) Ltd | Wembley | 2020 |
| 4 Seasons Glazing Ltd | Peterborough | 2022 |
| 4 Stars Group Ltd | Birmingham | 2026 |
| 4 U Cars Limited | Berkshire | 1978 |
| 4 Way Mechanical Limited | King'S Lynn | 2017 |
| 4 Way Refrigeration Limited | King'S Lynn | 2004 |
| 4 Way Refrigeration Services Ltd | King'S Lynn | 2014 |
| 4 Wood Living Ltd | Tunbridge Wells | 2026 |
| 4 Wood Thinking Ltd | Tunbridge Wells | 2023 |
| 4 World Trade Ltd | Feltham | 2010 |
| 4 YOU Clothing Ltd | Nottingham | 2012 |
| 4 Your Long Hair Ltd | Bordon | 2024 |
| 4-D Building Services Ltd | Hoddesdon | 2022 |
| 40 Winks Sleep Ltd | London | 2021 |
| 40075 Limited | Sutton | 2013 |
| 400I Limited | Wirral | 2019 |
| 404 Bakes Ltd | Bristol | 2020 |
| 404 Dynamics Ltd | Belper | 2024 |
| 40CAKES Bakery Ltd | Morden | 2026 |
| 40FT Brewery Limited | London | 2015 |
| 40PARTS Ltd | Fleet | 2025 |
| 411 Beverages Limited | Manchester | 2018 |
| 411 Drinks Group Ltd | Oldham | 2026 |
| 411 Holdings Ltd | Sale | 2026 |
| 414 Alcohols Limited | Kirkcaldy | 2016 |
| 4160 Tuesdays Limited | London | 2012 |
| 42 Spinner Ltd | Worcester | 2025 |
| 42'S Records Ltd | Manchester | 2019 |
| 427 Hardtops Limited | London | 2021 |
| 42ND Floor Studios Ltd | Milton Keynes | 2025 |
| 432 Higher ZEN Ltd | Nantwich | 2024 |
| 435 Cameras Limited | London | 1996 |
| 44 Boxing Ltd | Coventry | 2024 |
| 442 Apparel Ltd | Newtownards | 2022 |
| 442 Events Limited | Wokingham | 2006 |
| 444 Ventures Ltd | Manchester | 2025 |
| 45 Hound Black Limited | Dundee | 2021 |
| 47 Brand Europe Limited | Milton Keynes | 2011 |
| 47 Degrees Coffee Ltd | Heanor | 2014 |
| 47 Skin Ltd | Huddersfield | 2018 |
| 471 Print & Promotions Limited | Sheffield | 2015 |
| 47324 Project Limited | Manchester | 1999 |
| 47CHOCO Ltd | London | 2025 |
| 48 Tees Limited | Tunbridge Wells | 2021 |
| 481 Supplies Ltd | London | 2022 |
| 48624 Locomotive Company Limited | Loughborough | 1990 |
| 48V@LOW Carbon Heat Ltd | Todmorden | 2025 |
| 49 Drive by Brews and Barms Ltd | Sale | 2025 |
| 493K Limited | Ballyclare | 2003 |
| 49GERS Enterprises Limited | Glasgow | 2025 |
| 49GERS Ltd | Glasgow | 2025 |
| 4ALL LAB Limited | London | 2023 |
| 4AMIGOS Ltd | London | 2011 |
| 4APRINTS Ltd | Woodford Green | 2025 |
| 4AX Technologies Limited | London | 2016 |
| 4B Braime Components Limited | | 1974 |
| 4B Elevator Components Limited | | 1962 |
| 4BASEBIO UK Ltd | Cambridge | 2019 |
| 4BIDDEN Limited | Bury | 2011 |
| 4BIND Limited | Stevenage | 2015 |
| 4BOOKS Group Limited | Leigh-On-Sea | 2015 |
| 4BW Limited | Norwich | 2011 |
| 4C Electronics Limited | Cleveland | 1979 |
| 4C Lighting Solutions Ltd. | Jarrow | 2024 |
| 4C the Bakery Ltd | Newry | 2025 |
| 4C'S Taylor Engineering Limited | Grimsby | 2026 |
| 4CAPRICORNS UK Ltd | Bradford | 2024 |
| 4CARDS Limited | Harrow | 2023 |
| 4CLASSICS-1956 Ltd | Manchester | 2024 |
| 4CNC Ltd | Wolverhampton | 2004 |
| 4CORE Nutrition Ltd | Cambridge | 2025 |
| 4CORNER Concepts Limited | Leeds | 2024 |
| 4COURT Solutions Limited | Bracknell | 2006 |
| 4CTIVE Limited | Redditch | 2023 |
| 4D Auto Locksmith Limited | London | 2025 |
| 4D Bdormant Ltd | Nottingham | 2020 |
| 4D Biomaterials Ltd | Nottingham | 2023 |
| 4D Coils Limited | Cramlington | 2015 |
| 4D Creations Limited | Leeds | 2015 |
| 4D Full Arch Limited | Birmingham | 2025 |
| 4D Medical Devices Ltd | Nottingham | 2023 |
| 4D Medicine Ltd | Nottingham | 2018 |
| 4D Modelshop Limited | Kingston Upon Thames | 2002 |
| 4D Numberplates Direct Ltd | Ilkeston | 2021 |
| 4D Plant Hire Limited | Burnley | 2025 |
| 4D Plates Ltd | Manchester | 2018 |
| 4D Shopfitting Ltd | Gloucester | 2016 |
| 4DEGREESC Limited | London | 2002 |
| 4DOWN Distribution Limited | Hastings | 2006 |