| 360 Degree Transformations Ltd | Nottingham | 2020 |
| 360 Degrees Ltd | Barnsley | 2024 |
| 360 Ground Contractors Ltd | Amersham | 2021 |
| 360 Preview Ltd | Stockport | 2015 |
| 360 Property Investment Limited | Darvel | 2017 |
| 360 Recruitment Partners Ltd | Nottingham | 2019 |
| 360 Site Survey Ltd | Solihull | 2014 |
| 360FIRST Limited | Leeds | 2012 |
| 365 Bargains Limited | Swadlincote | 2015 |
| 365 Environmental Services Limited | Walsall | 1973 |
| 365 FM Ltd | Telford | 2022 |
| 365 RTM Company Limited | Blackburn | 2026 |
| 365 Vehicle Logistics Limited | Gainsborough | 2016 |
| 365 Watches Limited | London | 2018 |
| 366 LEE High Road Limited | Newcastle Upon Tyne | 2005 |
| 369 Property Ltd | Waltham Cross | 2021 |
| 36T Limited | Swadlincote | 2024 |
| 37 Devonshire Road Limited | London | 2006 |
| 37 Eversfield Place Management Ltd | Bexhill | 2016 |
| 37 Green Lane Management Co Limited | Manchester | 1988 |
| 37 Hervey Close Management Company Limited | Iver Heath | 2015 |
| 37 Holbeach Road Ltd | London | 2010 |
| 37 Vernon Terrace (Brighton) Limited | Hove | 2006 |
| 37 West Hill Road Limited | Bexhill | 1998 |
| 37-38 Bedford Square RTM Company Limited | Brighton | 2025 |
| 37-39A Wellesley Road Management Limited | London | 2003 |
| 374 Durham Road Management Company Limited | Newcastle Upon Tyne | 2014 |
| 3755TH Single Member Shelf Trading Company Limited | London | 2026 |
| 38 Berrymede RTM Limited | York | 2009 |
| 38 Cambridge Road (Plymouth) Limited | Liskeard | 2008 |
| 38 Coleshill Street (Sutton Coldfield) Limited | Sutton Coldfield | 2012 |
| 38 Dixon Street Limited | Standlake | 2011 |
| 38 Horne Road Ilfracombe Management Company Limited | Ilfracombe | 2016 |
| 38 Q Avenue Freehold Limited | London | 2016 |
| 38 Sutherland Street Residents Association Limited | Colchester | 2011 |
| 38 Thompson Road (Freehold) Limited | London | 2008 |
| 384 New Cross Road (Freehold) Limited | London | 2015 |
| 387 Southwark Park Road Limited | | 2003 |
| 388 Queensbridge Road Property Management Company Limited | Glossop | 2012 |
| 39 Cranwich Road Limited | London | 2008 |
| 39 Edin Ltd. | Edinburgh | 2006 |
| 39 Hampton Park Redland Limited | Bristol | 2015 |
| 39 Landseer Road Limited | London | 2000 |
| 39 Lyham Road Limited | London | 2008 |
| 39 Pretoria Avenue (Freehold) Limited | London | 2017 |
| 39 Spencer Road Limited | London | 2008 |
| 39 ST. Hilda's Avenue Management Company (1985) Limited | Ashford | 1985 |
| 39 Vanguard Way Ltd | Leigh On Sea | 2021 |
| 39 Ventnor Villas (Hove) Limited | Hove | 2009 |
| 39-41 Boutport Street Limited | Northampton | 2023 |
| 39-45 Stein Road Southbourne Limited | Emsworth | 2003 |
| 39-51 Highgate Road (Real Estate) Limited | London | 2015 |
| 39-51 Highgate Road (Residential) Limited | London | 2015 |
| 39-54 Baltic Place RTM Company Limited | Stanmore | 2014 |
| 39/41 ALL Saints Road Limited | London | 2007 |
| 39/41 Barnsdale Road Reading Limited | Berkshire | 1994 |
| 392 to 402 Lillie Road Limited | London | 2012 |
| 396 Fishponds Road Management Limited | Bristol | 1991 |
| 399 Anlaby Management Ltd | Stamford | 2009 |
| 3A Industry Ltd | London | 2008 |
| 3A Scaffolding Ltd | Solihull | 2015 |
| 3A Studios Ltd | London | 2023 |
| 3A'S RMN Limited | Rushden | 2022 |
| 3ANDTHREECROWS Ltd | Hemel Hempstead | 2023 |
| 3B Trading Ltd | Cambridge | 2023 |
| 3B4 Investments Limited | Stockport | 2021 |
| 3C Bridgewater Street RTM Company Limited | Liverpool | 2023 |
| 3CALS Ltd | London | 2007 |
| 3D Aluminium Limited | Witney | 1987 |
| 3D Cabinet Flow Ltd | Northolt | 2024 |
| 3D Design Associates Ltd | Towcester | 2012 |
| 3D Facilities Management Limited | Sutton Coldfield | 2018 |
| 3D Print Farm Ltd | London | 2020 |
| 3D Specialist Contracting Ltd | Southampton | 2015 |
| 3D Yachting Ltd | London | 2021 |
| 3DLEIGH Limited | Essex | 2007 |
| 3DREAM Ltd | London | 2021 |
| 3DW (Print Services) Ltd | Swansea | 2016 |
| 3GO Ltd | Grantham | 2022 |
| 3HELIX Management Ltd | Edinburgh | 2012 |
| 3HOLDS Management Limited | London | 2015 |
| 3I Evolution Limited | Manchester | 2023 |
| 3KITES Technologies Ltd | Woking | 2006 |
| 3LITTLEBIRDS Care UK Ltd | Witney | 2024 |
| 3LPS Developments Ltd | Newport | 2019 |
| 3M Investments Ltd | Coventry | 2022 |
| 3MAN Capital Limited | Loughton | 2015 |
| 3MC2 Limited | Leigh-On-Sea | 2023 |
| 3N Engineering & Consultancy Services Limited | Enfield | 2016 |
| 3N2 Ltd | Leicestershire | 2011 |
| 3PEAKSTIMBER Limited | Settle | 2009 |
| 3PUL4 UK Ltd | Northampton | 2022 |
| 3Q Sports Limited | Huntingdon | 2023 |
| 3Q Trades Ltd | Stoke-On-Trent | 2019 |
| 3Q Workwear Limited | Huntingdon | 2023 |
| 3R Trade Dynamics (UK) Limited | Leicester | 2014 |
| 3SIZEDOWN Limited | London | 2022 |
| 3SW Limited | Weybridge | 2007 |
| 3UK Retail Limited | Reading | 2006 |
| 3VEDI Solutions Limited | London | 2015 |