| 12 Lichfield Road Limited | | 2002 |
| 12 Lime Hill Road Limited | Kent | 2006 |
| 12 Limes Grove Limited | London | 2001 |
| 12 Linden Gardens Limited | London | 2021 |
| 12 Lindfield Gardens (Management) Ltd | London | 1998 |
| 12 Littlegate Street Limited | Wokingham | 2008 |
| 12 London Road Residents Company Limited | Sawbridgeworth | 1982 |
| 12 Lordship Park Limited | Worthing | 1983 |
| 12 Lorna Road (Hove) Limited | Hove | 1998 |
| 12 Lower Market Street Limited | Truro | 2014 |
| 12 Lower Oldfield Park Management Company Limited | Harlow | 2008 |
| 12 Lower Rock Gardens Brighton Limited | East Sussex | 2006 |
| 12 Lowfield Road Freehold Limited | London | 2015 |
| 12 Lynn Road Limited | London | 2004 |
| 12 Malvern Road Limited | London | 2024 |
| 12 Manor Road, Paignton Management Limited | Paignton | 2025 |
| 12 Manvers Street Management Company Ltd | Lutterworth | 2015 |
| 12 Marine Parade Folkestone Management Company Limited | Morpeth | 2014 |
| 12 Marine Parade Management Company Limited | Clevedon | 2003 |
| 12 Marine Square (Brighton) Limited | Brighton | 2014 |
| 12 Mary Street Management Company Limited | Porthcawl | 2012 |
| 12 Maude Road (Camberwell) Limited | London | 2020 |
| 12 Mazenod Avenue Ltd | Tring | 1999 |
| 12 Melrose Place Management Company Limited | Shepton Mallet | 1984 |
| 12 Milburn Road (Management) Limited | Weston-Super-Mare | 2005 |
| 12 Mildmay Grove South Freehold Limited | London | 2017 |
| 12 Miles Road, Clifton (Management) Limited | Bristol | 1980 |
| 12 Milespit Hill Freehold Limited | London | 2012 |
| 12 Milford Street Management Limited | Bristol | 1992 |
| 12 Milverton Road Management Limited | | 1997 |
| 12 Minden Road Freehold Limited | London | 2024 |
| 12 Molyneux Park Road Limited | Tunbridge Wells | 2004 |
| 12 Molyneux Park Road Residents Company Limited | Tunbridge Wells | 2003 |
| 12 Montpelier Management Company Limited | Weston-Super-Mare | 2015 |
| 12 Montpellier Villas Management Limited | Cheltenham | 2004 |
| 12 Moorhouse Road RTM Company Limited | London | 2021 |
| 12 Moray Road N4 3LG Ltd | London | 2024 |
| 12 Moreton Road CR2 Limited | London | 2024 |
| 12 Morley Road RTM Company Limited | London | 2017 |
| 12 Nevern Square (Management Company) Limited | London | 2016 |
| 12 New Steine Freehold Company Limited | Brighton | 2024 |
| 12 Nightingale Road (Southsea) Limited | Southsea | 2021 |
| 12 Norfolk Road Maidenhead Management Company Limited | Maidenhead | 1991 |
| 12 Norfolk Terrace Brighton Management Company Limited | East Sussex | 1987 |
| 12 North Road Residents Association Limited | Surbiton | 1995 |
| 12 Northumberland Square Management Company Limited | North Shields | 2025 |
| 12 Old High Street Management Company Limited | Bicester | 2019 |
| 12 Old Road Management Limited | Frinton-On-Sea | 2014 |
| 12 Oriental Place Management Company Limited | East Sussex | 2004 |
| 12 Ormonde Gate Freehold Limited | London | 2019 |
| 12 Ormonde Gate Leasehold Limited | London | 2021 |
| 12 Osborne Road Management Co. Limited | Bristol | 1983 |
| 12 Overcliff Road Ltd | Maidstone | 2007 |
| 12 Owls Road RTM Company Ltd | Bournemouth | 2026 |
| 12 Oxford Road Exeter Management Co Limited | New Milton | 1982 |
| 12 Oxford Road Management Limited | London | 1992 |
| 12 Paisley Road RTM Company Limited | Bournemouth | 2026 |
| 12 Palmeira Avenue Hove Freeholders Company Limited | Brighton | 2005 |
| 12 Paradise Place Limited | Westgate | 2017 |
| 12 Park Avenue Management Company Limited | Torquay | 2001 |
| 12 Park Lane Limited | Bath | 2020 |
| 12 Park Road Limited | Wirral | 1975 |
| 12 Park Road RTM Company Limited | Wallington | 2007 |
| 12 Park Street (Dover) RTM Company Limited | Gravesend | 2012 |
| 12 Parklands (Surbiton) Limited | Surbiton | 1970 |
| 12 Pear Breaks Freehold Limited | London | 2019 |
| 12 Peckham Hill Street (Freehold) Limited | Exeter | 2015 |
| 12 Pennsylvania Road Management Company Limited | Exeter | 1988 |
| 12 Pepys Road Management Company Limited | | 2002 |
| 12 Philbeach Gardens Management Limited | | 1989 |
| 12 Powell Road Limited | London | 2016 |
| 12 Powis Square (Brighton) Freehold Limited | Hove | 2021 |
| 12 PR RTM Company Limited | Bournemouth | 2025 |
| 12 Preston Park Avenue Brighton Limited | East Sussex | 2001 |
| 12 Priory Avenue (Hastings) Limited | Hastings | 2002 |
| 12 Q a Gate Ltd | London | 2023 |
| 12 Quantock Road Management (Bristol) Limited | Bristol | 2016 |
| 12 Radipole Road Limited | London | 2010 |
| 12 Randolph Crescent Limited | London | 1983 |
| 12 Ranelagh Grove Limited | Southampton | 1994 |
| 12 Range Road Limited | Altrincham | 1997 |
| 12 Rattray Road Freehold Limited | London | 2025 |
| 12 RCS Management Limited | Scarborough | 2021 |
| 12 Recreation Road RTM Company Limited | Godalming | 2013 |
| 12 Redcliffe Square Management Limited | | 1998 |
| 12 Redington Road Freehold Limited | London | 2003 |
| 12 Richmond Road RTM Company Ltd | London | 2016 |
| 12 Richmond Terrace Management Limited | Bristol | 2025 |
| 12 Rivers Street Bath Ltd | Bath | 2026 |
| 12 Royal Buildings Management Company Limited | Penarth | 2006 |
| 12 Royal Crescent (Bath) Management Company Limited | Bath | 1976 |
| 12 Royal Crescent (Whitby) Limited | Whitby | 2001 |
| 12 Royal Road Ramsgate RTM Company Limited | Ramsgate | 2013 |
| 12 Royal York Crescent Management Limited | Bristol 8 | 1984 |
| 12 Russell Street (Management Company) Limited | Bath | 2002 |
| 12 Rutland Gate Limited | London | 1983 |
| 12 Salisbury Road Property Management Limited | London | 2010 |
| 12 Schubert Road Management Company Limited | London | 2005 |
| 12 Seaview Management Limited | Newry | 2025 |
| 12 Seaview Road Management Company Limited | Burnham-On-Sea | 1999 |