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| 6-LOGIC Ltd | Knoll Rise | 2013 |
| 6-PM Limited | Wilmslow | 2020 |
| 6-SENSE Automation GmbH Limited | Halifax | 2021 |
| 6/6EYECARE Ltd | London | 2015 |
| 60 - 62 Palace Road Freehold Limited | London | 2007 |
| 60 Clapham Common South Side Limited | | 2004 |
| 60 Consulting Ltd | Slough | 2018 |
| 60 Eastbury Grove Management Company Limited | | 2003 |
| 60 Ellington Street Limited | | 1990 |
| 60 Redcliffe Gardens Limited | Woking | 2004 |
| 60 Sandford Road (Freehold) Company Limited | West Wickham | 2010 |
| 60 Scott Street Limited | London | 2024 |
| 60 Second Makeover Limited | Macclesfield | 2011 |
| 60 Shooters Hill Road Management Company Limited | London | 1986 |
| 60 Westby Street (Lytham) Management Company Limited | Blackpool | 2014 |
| 60-63 Broomlee Road Freehold Limited | Newcastle Upon Tyne | 2014 |
| 600 Strategy Ltd | Dorking | 2020 |
| 6000 Opportunities Limited | Upminster | 2020 |
| 600C Consulting Limited | Oxfordshire | 2015 |
| 600THOUSAND Ltd | Weybridge | 2024 |
| 601 Consultancy Ltd | Portsmouth | 2022 |
| 603 Copywriting Limited | Manchester | 2017 |
| 6030 Design and Build Ltd | Belfast | 2018 |
| 604 Taxis Ltd. | Bonnyrigg | 2014 |
| 605 Support Ltd | Staines-Upon-Thames | 2019 |
| 60BC Limited | Huddersfield | 2018 |
| 60DS Consulting Ltd | London | 2025 |
| 60H Limited | Hook | 2025 |
| 60KL Ltd | Colchester | 2017 |
| 60STICKS Ltd. | Holmfirth | 2005 |
| 60TLI Consulting Limited | Lincoln | 2022 |
| 60WR Limited | Plymouth | 2008 |
| 61 Clouds Hill Road, ST George, Bristol (Management) Limited | Bristol | 1990 |
| 61 Consultancy Limited | Leamington Spa | 2021 |
| 61 Drayton Park Limited | London | 2000 |
| 61 Hencroft Street South RTM Company Ltd | Maidenhead | 2013 |
| 61 Live Entertainment Ltd | Nottingham | 2024 |
| 61 ST. Margarets Road (Management) Limited | | 1982 |
| 61 Teignmouth Road Limited | | 1986 |
| 61 Upper Brockley Road Limited | London | 2000 |
| 610 Consultants Ltd | Datchet | 2021 |
| 613 Consultancy Ltd | Wells | 2022 |
| 616 Group Limited | London | 2025 |
| 616 Taxis Ltd. | Edinburgh | 2017 |
| 617 Club Ltd | Bury St Edmunds | 2024 |
| 617 Consulting Limited | London | 2021 |
| 617 Edin Ltd. | Edinburgh | 2007 |
| 617 Engineering Services Ltd | Lincoln | 2022 |
| 617 Investments Ltd | London | 2025 |
| 618 Insight Ltd | Reading | 2016 |
| 61WORKS Ltd | East Malling | 2025 |
| 62 Castlewood Road Limited | London | 1990 |
| 62 Edin Ltd. | Edinburgh | 2007 |
| 62 GS Limited | Woodford Green | 1996 |
| 62 High Street Limited | Bristol | 2015 |
| 62 Longley Road Ltd | Tooting | 2014 |
| 62 Management Ltd | Leicester | 2016 |
| 62 Miles High Ltd | Manchester | 2015 |
| 62 Mulgrave Road Managements Limited | Sutton | 1987 |
| 62 Sandringham Crescent Management Co Ltd | Middlesex | 2005 |
| 62 Tyrwhitt Road Management Company Limited | | 1983 |
| 62 Warrington Crescent Limited | Tetbury | 1983 |
| 62-62A Wardo Avenue Management Company Limited | | 2005 |
| 622 Research & Consulting Limited | Tynemouth | 2009 |
| 622 Taxis Ltd. | Glasgow | 2015 |
| 622.DIGITAL Limited | Leeds | 2025 |
| 623 Curtis Consulting Limited | Swindon | 2025 |
| 623 Taxis Ltd. | Bonnyrigg | 2015 |
| 626MANAGEMENT Ltd | Crawley | 2017 |
| 62AM Limited | Walsall | 2023 |
| 62E Solutions Limited | London | 2021 |
| 63 Capital Partners UK Ltd | London | 2026 |
| 63 Denman Road RTM Company Limited | London | 2010 |
| 63 Hertz Limited | Waltham Abbey | 2012 |
| 63 Woodside Green (South Norwood) Management Company Limited | London | 2005 |
| 63/65 Myddelton Square Limited | London | 1996 |
| 631 Consultancy Ltd | Crowborough | 2023 |
| 631 Risk Ltd | Steyning | 2024 |
| 632 Consulting Limited | Purley | 2024 |
| 633 Media Ltd | Luton | 2016 |
| 636 Arcot Consulting Limited | Harrogate | 2024 |
| 6370 Ltd | Loughborough | 2021 |
| 64 Belgrave Management Ltd | Ilford | 2014 |
| 64 Braxfield Management Company Limited | London | 2003 |
| 64 Ladbroke Grove Limited | Altrincham | 1989 |
| 64 Southwell Road Limited | London | 1990 |
| 64 Ventures Limited | Bedford | 2024 |
| 64 WR Limited | Peterborough | 2013 |
| 644 Taxis Limited | Edinburgh | 2007 |
| 64HOLDINGS Ltd | Enfield | 2019 |
| 64TH & Social Ltd | Bicester | 2018 |
| 65 Davies Street Development Limited | London | 2015 |
| 65 Davies Street Investment Limited | London | 2015 |
| 65 Ennismore Gardens Management Limited | | 1992 |
| 65 Equity Partners Management (UK) Limited | London | 2021 |
| 65 Leigham Vale RTM Company Limited | London | 2011 |
| 65 Management Consultancy Ltd | Banbury | 2021 |
| 65 New Cavendish Street Management Limited | Cardiff | 2014 |
| 65 Ramsden Road Management Company Limited | London | 1989 |