| 56 ST Pauls Road Torquay Management Company Limited | Torquay | 2004 |
| 56 Turners Hill Limited | London | 2017 |
| 561 London Road (Block H) Management Company Limited | Grays | 1989 |
| 5663 Trading Ltd | Oldham | 2025 |
| 56789 Aberdeen Limited | Aberdeen | 2012 |
| 57 Devonport Road Limited | London | 2023 |
| 57 Harrow Road Limited | Wembley | 1965 |
| 57 Investigations and Security Limited | Shipley | 2020 |
| 57 Investigations Limited | Shipley | 2017 |
| 57 Live Ltd | London | 2008 |
| 57 Nightingale Lane Limited | | 1996 |
| 57 Power Rentals UK Ltd | St Ives | 2019 |
| 57 Security Ltd | Chesterfield | 2019 |
| 57.05 Limited | Banchory | 2018 |
| 579 ATP Limited | Billingham | 2016 |
| 58 Chaucer Road Limited | Bedford | 2011 |
| 58 Chesterton Road Management Limited | London | 1981 |
| 58 Services Ltd | Stockton-On-Tees | 2026 |
| 58-60 Nibthwaite Road Management Limited | Harrow | 2010 |
| 58CITI Limited | London | 2023 |
| 59 Charlotte Street Limited | Harrow | 2013 |
| 59 Drayton Gardens Limited | London | 2003 |
| 59 North Road (Combe Down) Management Company Limited | Bath | 2005 |
| 59 Oxford Road Management Committee Limited | Moseley | 2010 |
| 59 Southbourne Crescent (Freehold) Limited | London | 2008 |
| 59 SPV Ltd | Stockport | 2023 |
| 59&1ST Ltd | Lancing | 2018 |
| 590 Transport Ltd | Askam-In-Furness | 2026 |
| 593 Consultancy Services Limited | Maidstone | 2016 |
| 5985 Ltd | Hassocks | 2025 |
| 59PROCOM Limited | Cleckheaton | 2013 |
| 5AAB Events Ltd | Southall | 2024 |
| 5AM London Ltd | London | 2019 |
| 5APP Limited | London | 2010 |
| 5AS Limited | London | 2013 |
| 5C Group Ltd | Wickford | 2013 |
| 5C Promotions Ltd | Redditch | 2023 |
| 5C Travel Limited | London | 2025 |
| 5D Bespoke People Solutions Ltd | Ibstock | 2021 |
| 5D Events Limited | Bath | 2017 |
| 5D Solar Concept Ltd | London | 2017 |
| 5FT Hire Ltd | London | 2006 |
| 5G Cleaning Services Ltd | Morden | 2024 |
| 5G Recruitment Ltd | Stourbridge | 2019 |
| 5G Security Ltd | London | 2025 |
| 5GS Security Services Limited | Southampton | 2021 |
| 5HAW Limited | Mexborough | 2014 |
| 5I Group Limited | Ware | 2020 |
| 5IVE Management Limited | Didcot | 2004 |
| 5IVE Star Services Limited | Ilford | 2012 |
| 5IVEA Limited | London | 2018 |
| 5IVEKEYS Ltd | Luton | 2025 |
| 5IVES Rentals Ltd | Hounslow | 2023 |
| 5IVETECH Limited | London | 2017 |
| 5J Payroll Limited | Dundee | 2025 |
| 5K Cleaning Co. Ltd | Bury St. Edmunds | 2025 |
| 5K Global Limited | London | 2023 |
| 5M Lean Consultants Limited | Warrington | 2009 |
| 5M Safety and Security Services Limited | London | 2021 |
| 5M Travel Services Ltd | Milton Keynes | 2012 |
| 5NINES Media Ltd | Crewe | 2026 |
| 5Q Consultancy Limited | Godalming | 2012 |
| 5Q'S Ltd | Maidenhead | 2022 |
| 5RB Services Limited | East Grinstead | 2018 |
| 5RECRUIT Ltd | Birmingham | 2025 |
| 5S Recruitment Limited | Birmingham | 2022 |
| 5SAINTS Janitorial Services Ltd | Gravesend | 2023 |
| 5SENSES Hospitality Limited | Bracknell | 2016 |
| 5SR Property Holdings Ltd. | Dundee | 2016 |
| 5STAR Hand Car Wash & Valet Ltd | Walsall | 2024 |
| 5STAR-SECURITY Solutions Ltd | Welling | 2022 |
| 5STARCLEAN Ltd | London | 2023 |
| 5STARMEMBERS Ltd | London | 2013 |
| 5STARS J&A Ltd | Edgware | 2020 |
| 5STARSOURCING Ltd | Reading | 2024 |
| 5STARX Mystery Customer Experience Limited | Stirling | 2025 |
| 5T Publishing Limited | Cheadle Hulme | 2002 |
| 5TANI Ltd | Ilford | 2025 |
| 5TARS Cleaning Service Ltd | Marlow | 2024 |
| 5TC’S Ltd | Bognor Regis | 2023 |
| 5TH Avenue Cleans Ltd | Lanark | 2026 |
| 5TH GEN Cleaning Ltd | Norwich | 2023 |
| 5TH Industrial Revolution International CIC | London | 2021 |
| 5TH Please Ltd | London | 2023 |
| 5V Limited | Wirral | 2009 |
| 5VALUES Consulting Group Ltd | Bristol | 2016 |
| 5VHIRE Ltd | Stroud | 2023 |
| 5X15 Holdings Limited | London | 2025 |
| 5X15 Limited | London | 2009 |
| 5XPERFORMANCE Ltd | London | 2018 |
| 6 4 G Ltd | Worthing | 2010 |
| 6 Aesthetics and Skin Clinic Ltd | Leeds | 2024 |
| 6 Blatchington Road Limited | East Sussex | 2008 |
| 6 Bramley Hill RTM Company Ltd | Shrewsbury | 2014 |
| 6 Cornwall Road Management Company Limited | London | 2006 |
| 6 Dancer Road Limited | Bristol | 2003 |
| 6 Day Films Ltd | London | 2022 |
| 6 Degree Media Ltd. | London | 1984 |
| 6 Degrees Talent Digital Limited | London | 2016 |
| 6 Degrees Talent Limited | London | 2011 |