| 21 / 23 Eardley Crescent Limited | London | 2005 |
| 21 23 Ltd | Selkirk | 2026 |
| 21 Aberdy Limited | Swansea | 2017 |
| 21 Adolphus Road RTE Company Limited | London | 2010 |
| 21 Ainsdale Gardens Limited | Birmingham | 2024 |
| 21 Albion Street Freehold Limited | Brighton | 2021 |
| 21 Ambleside Limited | London | 2021 |
| 21 ARV Manco Limited | London | 2016 |
| 21 Balfour Road Limited | London | 2008 |
| 21 Batcliffe Drive Management Company Limited | Leeds | 2017 |
| 21 Beacon Road Limited | London | 2000 |
| 21 Beechworth Road (Havant) Management Limited | Portsmouth | 2023 |
| 21 Birkbeck Road (Management Company) Limited | London | 2002 |
| 21 Bishopsbridge Road Management Company Limited | London | 1982 |
| 21 Borough House Management Limited | Wimborne | 2003 |
| 21 Brading Road Management Limited | London | 2011 |
| 21 Bridge Street Chepstow Management Company Limited | Chepstow | 1994 |
| 21 Broad Court Management Limited | Cardiff | 2014 |
| 21 Broomfield Road Limited | Surbiton | 2021 |
| 21 Burlington Road Management Ltd | Romford | 2023 |
| 21 Capital Management Ltd | Derby | 2026 |
| 21 Carmalt Gardens Limited | London | 2023 |
| 21 Cedar Road Management Limited | Epsom | 1987 |
| 21 Century Homes Ltd | Blackburn | 2019 |
| 21 Century Limited | Aylesbury | 2023 |
| 21 Chatsworth RD Limited | Harrow | 2022 |
| 21 Cheltenham Place Ltd | Brighton | 2022 |
| 21 Claverton Buildings (Management) Limited | Bath | 1988 |
| 21 Clifton Crescent (Folkestone) Freehold Company Limited | Sittingbourne | 2008 |
| 21 Collingham Place Limited | London | 2023 |
| 21 Corrance Road RTM Company Limited | Washington | 2021 |
| 21 Crossfield Road (Freehold) Limited | London | 1998 |
| 21 D Property Limited | Newcastle Upon Tyne | 2025 |
| 21 Davies Street Limited | London | 2002 |
| 21 Devonshire Place (Brighton) Freeholder Limited | Brighton | 2015 |
| 21 Dora Road RTM Company Limited | London | 2026 |
| 21 Drive Ltd | Manchester | 2026 |
| 21 Eight Properties Ltd | Sunderland | 2025 |
| 21 ELM Road Limited | Kent | 2003 |
| 21 Florence RTM Company Ltd | Bournemouth | 2015 |
| 21 Fourth Avenue Limited | Hove | 2008 |
| 21 Fulbourn Road Ltd | Borehamwood | 2025 |
| 21 Garnet Street Limited | Keighley | 2016 |
| 21 Gloucester Street Limited | Deal | 1990 |
| 21 Golders Green Crescent Management Limited | London | 2014 |
| 21 Grafton Road Acton Limited | | 1999 |
| 21 Greek Street Ltd | London | 2023 |
| 21 Grimston Gardens Flat Management Co Ltd | Folkestone | 2023 |
| 21 Grimston Gardens Management Company Limited | Folkestone | 2020 |
| 21 Grove Place Management Company Limited | Henley-On-Thames | 2006 |
| 21 Halliwell Street Limited | London | 2018 |
| 21 Hansler Road Limited | London | 2003 |
| 21 Hillmarton Road Limited | London | 1999 |
| 21 Housing Ltd | Ruislip, | 2024 |
| 21 Howard Road Ltd | London | 2024 |
| 21 Jacksons Lane Limited | London | 1982 |
| 21 JTW Estates Limited | Kingsbridge | 2026 |
| 21 Kempsford Gardens Limited | London | 2018 |
| 21 Kenilworth Limited | Warwick | 2013 |
| 21 Kensington Church Walk Management Company Limited | Chelmsford | 1991 |
| 21 Kensington Place RTM Company Limited | Bath | 2015 |
| 21 Khyber Road Limited | London | 1999 |
| 21 Kyvdot Ltd | London | 2023 |
| 21 Lark Lane Ltd | Liverpool | 2024 |
| 21 Lavender Gardens Ltd | London | 2006 |
| 21 Leigh Street Ltd | Manchester | 2019 |
| 21 Lessing Street Limited | London | 2014 |
| 21 Lettings Limited | Newcastle Upon Tyne | 2015 |
| 21 Lever Street Management Company Limited | London | 2002 |
| 21 Littlehampton Road RTM Company Limited | Worthing | 2007 |
| 21 Living ACL Limited | Altrincham | 2022 |
| 21 Living Altrincham 2.0 Ltd | Altrincham | 2023 |
| 21 Living Altrincham High Street Limited | Altrincham | 2024 |
| 21 Living Altrincham Limited | Altrincham | 2021 |
| 21 Living Developments Limited | Stockport | 2025 |
| 21 Living Residential Limited | Altrincham | 2023 |
| 21 Living Sale Limited | Altrincham | 2022 |
| 21 Living SPV001 Ltd | Altrincham | 2025 |
| 21 Lurline Gardens RTM Company Limited | London | 2011 |
| 21 Lushington Road Limited | Exeter | 2017 |
| 21 MAC Ltd | Inverurie | 2018 |
| 21 Marlborough Road Management Limited | Buxton | 2003 |
| 21 Marlborough Road RTM Company Limited | Banbury | 2009 |
| 21 Marloes Road Management Company Limited | Rickmansworth | 2013 |
| 21 Mcintosh Road (Freehold) Limited | Romford | 2015 |
| 21 Montefiore Road (Hove) Limited | Brighton | 2004 |
| 21 Napier Place Management Company Limited | Hailsham | 2006 |
| 21 Napier Road Ltd | London | 2024 |
| 21 Nightingale Road Ltd | Hampshire | 2025 |
| 21 North Parade Management Company Limited | Whitley Bay | 2008 |
| 21 Oakfield Road Management Limited | | 2005 |
| 21 Onyx Properties Ltd | London | 2019 |
| 21 Palma Road Limited | Ilford | 2019 |
| 21 Park Road Residents Limited | Twickenham | 2002 |
| 21 Park View Management Ltd | Harrogate | 2000 |
| 21 Passmore Street Limited | London | 2022 |
| 21 Pennsylvania Road Management Company Limited | Exmouth | 2014 |
| 21 Petherton Road Freehold Limited | London | 2017 |
| 21 Pine Ltd | Manchester | 2026 |
| 21 Plumbers ROW RTM Company Limited | Stanmore | 2011 |