| 5NANCIAL Limited | Bolton | 2018 |
| 5NRG Group Limited | Biggleswade | 2024 |
| 5O5 Design Ltd | Beckenham | 2026 |
| 5OES Holdings Limited | London | 2022 |
| 5OGC Limited | Hildenborough | 2024 |
| 5ON Group Limited | Reading | 2024 |
| 5ONE Interiors Ltd. | London | 2014 |
| 5OR6 Limited | Loughborough | 2012 |
| 5PA Architects Limited | Borough | 2015 |
| 5PICY Accountants Limited | Leyland | 2019 |
| 5PILLARS Media Ltd | London | 2015 |
| 5PUJ47980XK Limited | London | 2018 |
| 5Q Holdings Ltd | Wellingborough | 2008 |
| 5QS Consultancy Limited | Bognor Regis | 2016 |
| 5R'S Morales Ltd | U.K. | 2012 |
| 5RICH Ltd | London | 2023 |
| 5RJ Limited | London | 2016 |
| 5S Accountants Limited | Leicester | 2022 |
| 5S Accountants Online Limited | Leicester | 2022 |
| 5S Aviapro Solutions Ltd | Telford | 2020 |
| 5S Business Solutions Limited | Leicester | 2020 |
| 5S Business Support Limited | Leicester | 2023 |
| 5S Projects Limited | Harrow | 2019 |
| 5SG Media Limited | Lancaster | 2017 |
| 5SR Electrical Ltd | Dundee | 2024 |
| 5STAR Consulting Solutions Limited | Coventry | 2016 |
| 5SUBSEA Ltd | Truro | 2019 |
| 5SURE Gates UK Limited | Leeds | 2015 |
| 5T IDM Limited | Northampton | 2022 |
| 5T Ventures Ltd | Peterborough | 2020 |
| 5TH Avenue Investment Corporation Ltd | London | 2010 |
| 5TH Child Ltd | Blackpool | 2023 |
| 5TH Colour London Ltd | London | 2022 |
| 5TH Day Ltd | Chinnor | 2018 |
| 5TH Dgree Ltd. | Wolverhampton | 2022 |
| 5TH Floor Holdings Ltd | London | 2026 |
| 5TH Generation Solutions Limited | London | 2016 |
| 5TH Quadrant Ltd | London | 2019 |
| 5TH Quarter Financial Solutions Ltd | London | 2015 |
| 5TH Studio Ltd | Cambridge | 1997 |
| 5TH-AXIS Limited | Middlesex | 2003 |
| 5THREAD Ltd | Bolton | 2020 |
| 5TT Partners Limited | Stourbridge | 2018 |
| 5V.ENERGY Limited | Market Drayton | 2021 |
| 5VE Design Limited | Beaconsfield | 2005 |
| 5W & H Ltd | Bath | 2023 |
| 5W Press Ltd | London | 2013 |
| 5X Consulting Ltd | Southend-On-Sea | 2023 |
| 5X Farm Barns Management Company Limited | Frodsham | 2007 |
| 5X5 Design Ltd | London | 2026 |
| 5X5 Media Ltd | London | 2021 |
| 5XP Engineering Ltd | Lancashire | 2016 |
| 5XR Ltd | London | 2021 |
| 5XTECHNOLOGIES Ltd | Newtownabbey | 2016 |
| 5Y Consulting Limited | St. Albans | 2019 |
| 5Y Design Ltd | Glasgow | 2022 |
| 5YSAFETY Ltd | London | 2025 |
| 5YT Ltd | Newark | 2018 |
| 5ZAR Ltd | Northwood | 2023 |
| 6 Addiction | Thame | 2023 |
| 6 AM Studio Limited | Stevenage | 2022 |
| 6 Cats Norway Limited | Watford | 2016 |
| 6 Clarendon Rise Limited | London | 2001 |
| 6 Crags Ltd | Inverness | 2022 |
| 6 Darnaway Street Limited | Edinburgh | 2000 |
| 6 Days Only Limited | Huntingdon | 2011 |
| 6 Degrees (UK) Limited | London | 2014 |
| 6 Degrees Consulting Limited | Hitchin | 2025 |
| 6 Degrees Global Limited | London | 2021 |
| 6 Degrees Studios Ltd | London | 2021 |
| 6 Dumbarton Road Limited | London | 2022 |
| 6 Elements Outdoor Living Ltd. | Ipswich | 2019 |
| 6 Engineering Limited | Middlesbrough | 2011 |
| 6 EV Limited | Middlesex, Stanmore | 2022 |
| 6 FT Ltd | Doncaster | 2025 |
| 6 Gears Ltd | Aberdeen | 2026 |
| 6 Glebe Street Limited | London | 2015 |
| 6 Handel Street Limited | London | 2005 |
| 6 Hillside Management Ltd | Bristol | 2011 |
| 6 Keys Limited | Leicester | 2005 |
| 6 Lansdown Road Limited | Bath | 2008 |
| 6 Leaf Clover Limited | Leicester | 2024 |
| 6 Leagrove Road Management Limited | Clevedon | 1987 |
| 6 Levers Business Coaching Limited | Bury St. Edmunds | 2020 |
| 6 Needham Road Limited | Morpeth | 2004 |
| 6 Point Energy Limited | London | 2015 |
| 6 Princes Buildings (Bath) Management Company Limited | Bridgwater | 1989 |
| 6 Revs Limited | Camberley | 2014 |
| 6 S Media Limited | Lytham St. Annes | 2008 |
| 6 Seeds Limited | London | 2023 |
| 6 Sided Dice Ltd | Colchester | 2024 |
| 6 ST John's Hill Management Limited | Tunbridge Wells | 2012 |
| 6 Stars Consultancy Limited | Dartford | 2021 |
| 6 TEN 70 Limited | Ipswich | 2015 |
| 6 to 8 Boroughgate Property Management Limited | Otley | 2017 |
| 6 Two 6 Ltd | London | 2013 |
| 6 Week Challenge Ltd | Christchurch | 2019 |
| 6 Wellington Road RTM Company Limited | Newark | 2006 |
| 6 Westcliff Avenue Management Company Limited | Westcliff-On-Sea | 2012 |
| 6&7 Gables Drive Company Limited | Southwell | 2004 |