| 21 Popham Street Management Company Limited | London | 2001 |
| 21 Port Hall Road (Brighton) RTM Company Limited | Brighton | 2025 |
| 21 Portarlington Freehold Limited | Bournemouth | 2006 |
| 21 Portland House Limited | Westgate-On-Sea | 2010 |
| 21 Powis Square Freehold Limited | Shoreham-By-Sea | 2016 |
| 21 Powis Square Limited | Shoreham-By-Sea | 1994 |
| 21 Prince of Wales Avenue (Reading) Management Company Limited | Reading | 1999 |
| 21 Prinsep Road Management Ltd | Haywards Heath | 2024 |
| 21 Property and Facilities Management Limited | Manchester | 2026 |
| 21 Quarry Hill Limited | Midhurst | 2016 |
| 21 Queens Drive Limited | London | 2005 |
| 21 Queens Road Freehold Limited | Twickenham | 2013 |
| 21 Queens Road Limited | Kent | 2006 |
| 21 Ranelagh Villas RTM Company Limited | Hove | 2009 |
| 21 Rectory Grove Limited | Bakewell | 2021 |
| 21 Redcliffe Square Limited | London | 1998 |
| 21 Regent Street Management Company Limited | Oxford | 2014 |
| 21 Richborne Terrace Residents Company Limited | | 2001 |
| 21 Richmond Crescent Flats Ltd. | London | 2004 |
| 21 Richmond Terrace Bristol Management Company Limited | Bristol | 2004 |
| 21 Robin Hood Lane Sutton Limited | Victoria | 1978 |
| 21 Rocks Lane RTM Company Ltd | Leamington Spa | 2016 |
| 21 Rodney Street RTM Company Limited | Liverpool | 2012 |
| 21 Roedale Road Brighton Limited | East Sussex | 1992 |
| 21 Rosendale Road Management Group Limited | London | 2025 |
| 21 Rosslyn Hill (Freehold) Limited | London | 2015 |
| 21 Sandrock Road Freehold Limited | London | 2022 |
| 21 SCN RTM Company Limited | Marden | 2006 |
| 21 Seaforth Management Limited | Westcliff On Sea | 2009 |
| 21 Sheen Park Richmond Limited | Surrey | 2002 |
| 21 Shelley Road (Worthing) Limited | Worthing | 2021 |
| 21 Shepherds Hill Management Company Limited | London | 2000 |
| 21 Sinclair Gardens Limited | | 1999 |
| 21 Solent Road Limited | London | 1997 |
| 21 Southampton Street Management Limited | Farnborough | 1989 |
| 21 Southey Road Management Limited | Epsom | 1996 |
| 21 Southleigh Road Management Company Limited | Bristol | 1987 |
| 21 Southville Place Management Company Limited | Bristol | 2022 |
| 21 Springfield Road (Brighton) Limited | Brighton | 2011 |
| 21 Springfield Road Management Company Limited | Ringwood | 2022 |
| 21 ST Annes Road Freehold Limited | Eastbourne | 2016 |
| 21 ST James's Square (Bath) Limited | Bath | 1998 |
| 21 ST Stephens Avenue Ltd | London | 2007 |
| 21 ST. Annes Road (Eastbourne) RTM Company Limited | Eastbourne | 2012 |
| 21 ST. Philip's Road Limited | Monmouth | 2010 |
| 21 Stanley Avenue Bristol Management Company Limited | Bristol | 2008 |
| 21 Stanley Road Limited | Teddington | 2007 |
| 21 Stansfield Road Limited | | 2006 |
| 21 Station Avenue Walton Residents Limited | Sudbury | 2022 |
| 21 Station Road RTM Company Limited | London | 2016 |
| 21 Steeles Road Limited | London | 2021 |
| 21 STF Limited | London | 2020 |
| 21 Stowe Road Limited | Sevenoaks | 2003 |
| 21 Surrey Road Management Company Limited | Poole | 2004 |
| 21 Sylvan Limited | London | 2017 |
| 21 Telford Avenue Management Co. Limited | | 1987 |
| 21 Temple Road (Epsom) Limited | Bromley | 2017 |
| 21 Temple Road (Epsom) RTM Company Limited | Bromley | 2013 |
| 21 the Little Boltons Limited | London | 1968 |
| 21 the Quadrant Freehold Limited | Windsor | 2012 |
| 21 Third Avenue (Hove) Freehold Company Limited | Hove | 2020 |
| 21 Trafalgar Square Management Company Limited | Scarborough | 2011 |
| 21 Treport Street Management Company Limited | London | 1996 |
| 21 Trinity Rise Freehold Company Limited | London | 2006 |
| 21 Union Road Limited | | 2002 |
| 21 Upper Belgrave Road Residents Association Limited | Bristol | 1998 |
| 21 Upperton Gardens Limited | East Sussex | 2003 |
| 21 Upton Park RTM Company Limited | Wokingham | 2005 |
| 21 Vallance Gardens Hove Limited | Hove | 2014 |
| 21 Vere Road Brighton Limited | Brighton | 2014 |
| 21 Walton Way Management Company Limited | London | 2024 |
| 21 Warrington Crescent Management Company Limited | London | 1993 |
| 21 Warwick Avenue (Bedford) Limited | | 1997 |
| 21 Waverley Grove Limited | Southsea | 1995 |
| 21 Wellington Crescent Management Company Ltd | Bristol | 2012 |
| 21 West Drive Brighton Limited | Hove | 2007 |
| 21 West Limited | Bristol | 2011 |
| 21 West Park (Clifton) Residents Management Limited | Clifton | 1983 |
| 21 Westbourne Park Freehold Limited | Kingston Upon Thames | 2025 |
| 21 Westcroft Square RTM Company Ltd | London | 2016 |
| 21 Westfield Park Management Limited | Bristol | 1984 |
| 21 Wharton Road Limited | Oxford | 2019 |
| 21 Whittinstall Road SW6 Limited | London | 2010 |
| 21 Wilbury Road Hove Limited | Hove | 2010 |
| 21 Wilbury Villas Limited | Hove | 2014 |
| 21 Wisteria RD Limited | London | 2019 |
| 21 Wisteria Road Management Company Limited | London | 2025 |
| 21 Wood END Road RTM Company Ltd | Harrow | 2022 |
| 21 Wood Vale Management Company Limited | West Wickham | 1984 |
| 21 Woodstock Road Management Company Limited | Bristol | 1983 |
| 21 Worlingham Road Management Company Limited | London | 2024 |
| 21 Wray Crescent Management Co. Limited | London | 2010 |
| 21 Zetland Road Limited | Hyde | 2009 |
| 21, Burlington Road Management (Bristol) Limited | Bristol | 1977 |
| 21, Heworth Place Management Limited | York | 1999 |
| 21, North Avenue Freehold Limited | Broadstairs | 2019 |
| 21, Tyndalls Park Road (Management) Limited | Bristol | 1986 |
| 21, Upper Church Road Management Company Ltd | Weston-Super-Mare | 1991 |
| 21, Vanbrugh Hill Management Company Limited | London | 1981 |
| 21-22 Gosfield Street Limited | London | 2010 |