| 4SCIENCES Group Ltd | Leighton Buzzard | 2020 |
| 4SGB Ltd | London | 2021 |
| 4SHAW Practice Solutions Ltd | Peterborough | 2013 |
| 4SHEL Holdings Ltd | Lytham St. Annes | 2017 |
| 4SIGHT Advisory Limited | Hastings | 2022 |
| 4SIGHT AI Ltd | London | 2026 |
| 4SIGHT Consultants Limited | Bedford | 2014 |
| 4SIGHT Consulting Ltd | London | 2024 |
| 4SIGHT Designs Limited | Brigsley | 2006 |
| 4SIGHT ES Limited | Nottingham | 2011 |
| 4SIGHT Seismic Limited | Aberdeen | 2016 |
| 4SITE Consulting Limited | Great Chesterford | 2006 |
| 4SITE Holdings Ltd | Saffron Walden | 2019 |
| 4SITE Management Services Limited | London | 2015 |
| 4SITE Project Services Limited | Ince | 2024 |
| 4SL Limited | Richmond | 2020 |
| 4SQRWEALTH Limited | Dagenham | 2010 |
| 4SQUARE Consulting Limited | | 1997 |
| 4STAMP Limited | Leamington Spa | 2026 |
| 4STRATEGIC Ltd | London | 2019 |
| 4SURE Accountancy Limited | Ipswich | 2013 |
| 4T Engineering Limited | Windsor | 2015 |
| 4T Investments Limited | Farnham | 2018 |
| 4T Project Services Ltd | Wigan | 2016 |
| 4T2 Ltd | Solihull | 2025 |
| 4T2 Sensors Ltd | Birmingham | 2016 |
| 4TEEZ Catering Ltd | Benfleet | 2018 |
| 4TELL IM Limited | Bury St Edmunds | 2020 |
| 4TH Consulting Ltd. | Glasgow | 2007 |
| 4TH Dimension Composites Limited | Cheadle | 2015 |
| 4TH Dimension Inc Ltd | London | 2021 |
| 4TH Dimension Partners Ltd | Wilmslow | 2025 |
| 4TH Estate Consults Limited | London | 2008 |
| 4TH Floor Design Ltd | Mold | 2022 |
| 4TH GEN Group Ltd | Cheadle | 2018 |
| 4TH Mason Limited | Preston | 2012 |
| 4TH Peak Ltd | Tadcaster | 2022 |
| 4TH Revolution Consulting Ltd | Skegness | 2023 |
| 4TH Revolution Management Consultancy Ltd | Kettering | 2018 |
| 4TH Square Ltd | Minehead | 2024 |
| 4TH Wall Consulting Limited | Canterbury | 2019 |
| 4TH West Limited | St. Austell | 2022 |
| 4TRANSLATIONS Ltd | | 2003 |
| 4TTUDE Enterprises Limited | Stamford | 2010 |
| 4TTUDE Ltd | Edinburgh | 2017 |
| 4TUNE Investments Limited | Southampton | 2015 |
| 4TURNERS Ltd | Solihull | 2024 |
| 4TV Accounting Ltd | Sherborne | 2022 |
| 4TWENTY2 Limited | Poole | 2007 |
| 4TY7 Ltd | Corby | 2025 |
| 4U Property Limited | Leatherhead | 2016 |
| 4U Rail & Civil Ltd | Merthyr Tydfil | 2016 |
| 4UATRO Limited | Dunstable | 2015 |
| 4ULINK Ltd | London | 2015 |
| 4URTESTING Ltd | Rushden | 2024 |
| 4V Limited | London | 2025 |
| 4VENTS Solutions Ltd | Poole | 2024 |
| 4VISA Limited | Bexhill On Sea | 2020 |
| 4W Environmental Limited | Chester | 2010 |
| 4W Group Ltd | Preston | 2022 |
| 4WARD Accountancy Services Limited | St. Albans | 2005 |
| 4WARD Architects Ltd | Shifnal | 2009 |
| 4WARD Contracting Group Ltd | Wisbech | 2016 |
| 4WARD Digital Limited | Cockermouth | 2020 |
| 4WARD Focus Ltd | Harrogate | 2022 |
| 4WARD Management Limited | Whitefield | 2018 |
| 4WARD Site Services Ltd | Rochester | 2024 |
| 4WARD Technologies Limited | Chichester | 2013 |
| 4WARD Testing Ltd | Worthing | 2012 |
| 4WARD Thinking Design Ltd | Solihull | 2018 |
| 4WARRS Investments Limited | Wimborne | 2018 |
| 4WATERTR Limited | Crieff | 2025 |
| 4WAY Consulting Ltd | London | 2014 |
| 4WH Solutions Ltd | Hounslow | 2024 |
| 4WI Limited | Leamington Spa | 2024 |
| 4WND Limited | Tiverton | 2024 |
| 4WOODS Ecology Limited | Southampton | 2003 |
| 4WRD Group Ltd | Manchester | 2025 |
| 4WW Consulting Limited | Ilkley | 2017 |
| 4X Global Research Ltd | London | 2017 |
| 4X4 and HGV Services Limited | Lancaster | 2014 |
| 4X4 in Schools Limited | Brighouse | 2004 |
| 4X4 Services Limited | Romsey | 1985 |
| 4X4&MORE Ltd | Bolton | 2023 |
| 4XL Professional Services Limited | London | 2013 |
| 4XP Limited | Stoughton | 2021 |
| 4YES IT Services Ltd. | Manchester | 2014 |
| 4ZERO.IO Ltd | Ilford | 2021 |
| 5 & 6 Hillside Close Limited | Walsall | 2011 |
| 5 8 6 Design Bureau Ltd | Huddersfield | 2022 |
| 5 Beaumont Crescent (West Kensington) Limited | London | 1999 |
| 5 Belsize Square Limited | Harrow | 1989 |
| 5 by 5 (2025) Ltd | Windlesham | 2025 |
| 5 by 5 Interpreting Limited | Hamilton | 2023 |
| 5 Caralous Creek Property Management Limited | Portsmouth | 2016 |
| 5 Cats Consulting Limited | Tunbridge Wells | 2024 |
| 5 Cats One Pixel Ltd | Littlehampton | 2026 |
| 5 Chancery Lane Ltd | Bristol | 2017 |
| 5 Circles Ltd | Chester Le Street | 2025 |
| 5 Clicks Legal Ltd | Walthamstow | 2021 |