| 51 Mill Hill Road Limited | Construction | 2018 |
| 51 Montagu Square Limited | Households | 2009 |
| 51 Muswell Hill London Limited | Extraterritorial | 2001 |
| 51 Nails Shop Ltd | Other services | 2025 |
| 51 Nevern Square Residents Limited | Households | 1997 |
| 51 North Property Group Ltd | Real estate | 2021 |
| 51 Northfield Avenue Freehold Ltd | Households | 2026 |
| 51 Northwold Road Management Limited | Real estate | 2017 |
| 51 Oakdale Road (RTM) Company Limited | Real estate | 2020 |
| 51 Oakhill Road Putney Management Company Limited | Households | 1998 |
| 51 Oakhurst Grove (Freehold) Company Limited | Households | 2010 |
| 51 Oakhurst Grove RTM Company Limited | Households | 2008 |
| 51 Palace Gardens Terrace Limited | Hospitality | 1981 |
| 51 Perham Road Limited | Households | 2001 |
| 51 Plus Ltd | Real estate | 2017 |
| 51 Poppleton Road Limited | Households | 2005 |
| 51 Pulross Road Freehold Limited | Households | 2021 |
| 51 RG GP LLP | | 2019 |
| 51 RG Limited Partnership | | 2019 |
| 51 RG Nominee 1 Limited | Real estate | 2019 |
| 51 RG Nominee 2 Limited | Real estate | 2019 |
| 51 Roderick Road Residents Ltd. | Households | 1996 |
| 51 Rosebery Gardens Limited | Real estate | 2002 |
| 51 Sandmere Road Limited | Professional & scientific | 2003 |
| 51 Shakespeare RD Freehold Company Ltd | Extraterritorial | 2017 |
| 51 Sherriff Road Freehold Management Limited | Households | 2002 |
| 51 Shooters Hill Road Management Company Limited | Households | 1987 |
| 51 South Street Limited | Households | 1979 |
| 51 ST Augustine's Road Freehold Company Limited | Households | 2020 |
| 51 ST. George's Square Limited | Households | 1979 |
| 51 Station Road LLP | | 2019 |
| 51 Station Road Management Limited | Households | 2015 |
| 51 Strathblaine Road Ltd | Real estate | 2015 |
| 51 Sutherland Avenue Management Limited | Households | 1982 |
| 51 Swinburne Avenue Broadstairs Limited | Households | 2018 |
| 51 Thorparch Road Limited | Households | 2016 |
| 51 Trent Road London Limited | Households | 2002 |
| 51 Victoria Crescent Management Limited | Real estate | 2008 |
| 51 Wardo Avenue Ltd | Households | 2025 |
| 51 Warrington Crescent Limited | Households | 1983 |
| 51 Warwick Avenue Limited | Administrative & support | 2006 |
| 51 Wells House Road Limited | Real estate | 2002 |
| 51 Westwood Hill Freehold Limited | Households | 2009 |
| 51 Whittingstall Road RTM Company Limited | Households | 2019 |
| 51 Winchester Street (Management) Limited | Real estate | 1976 |
| 51 Windmill Road RTM Company Limited | Households | 2019 |
| 51 York Road (Farnborough) Management Company Limited | Real estate | 2005 |
| 51(A) SGR Ltd | Households | 2018 |
| 51-53 Anerley Road RTM Company Limited | Households | 2009 |
| 51-53 Records Limited | Information & communication | 2019 |
| 51-53 Rockley Court RTM Company Ltd | Households | 2021 |
| 51-53 ST Paul's Management Limited | Households | 2013 |
| 51-57 Herbert Road Management Limited | Households | 2015 |
| 51-60 Prince of Wales Mansions Management Company Limited | Real estate | 1987 |
| 51-70 Waldemar Avenue Mansions RTM Company Limited | Households | 2004 |
| 51/53 Grays Inn Road Limited | Real estate | 2002 |
| 51/53 Ossington Street Freehold Limited | Households | 2002 |
| 51/55 Marlborough Hill Freehold Limited | Real estate | 2007 |
| 51/55 Marlborough Hill Management Company Limited | Households | 1997 |
| 511 Services Ltd | Administrative & support | 2025 |
| 512 Consultants Ltd | Professional & scientific | 2022 |
| 512 Design Limited | Professional & scientific | 2021 |
| 512 Films Ltd | Information & communication | 2025 |
| 512 Ventures Ltd | Information & communication | 2025 |
| 513 Lordship Lane Limited | Real estate | 2018 |
| 5149 Water Pump Ltd | Real estate | 2025 |
| 5150 Ltd | Arts & recreation | 2024 |
| 516A Ltd | Wholesale & retail | 2024 |
| 518 Dagenham Green Ltd | Real estate | 2025 |
| 518AM (UK) Limited | Financial services | 2024 |
| 51A Lampton Road Ltd | Real estate | 2019 |
| 51B Lampton Road Ltd | Real estate | 2019 |
| 51D Ermine Road Ltd | Real estate | 2023 |
| 51DNA Limited | Wholesale & retail | 2013 |
| 51DRA Ltd | Wholesale & retail | 2023 |
| 51F Limited | Construction | 2025 |
| 51HOMES Ltd | Real estate | 2022 |
| 51KR Ltd | Real estate | 2025 |
| 51KR Old Trafford Ltd | Real estate | 2024 |
| 51UNI Limited | Extraterritorial | 2016 |
| 51ZERO Estates Ltd | Real estate | 2025 |
| 52 Aberdeen Park (Freehold) Limited | Households | 1998 |
| 52 Acre Lane Management Company Limited | Households | 2001 |
| 52 Adelaide Avenue Ltd | Households | 2018 |
| 52 Alderbrook Road Limited | Households | 2021 |
| 52 Alderley Road LLP | | 2013 |
| 52 and 52A Oaklands Grove (Management) Limited | Real estate | 2001 |
| 52 Apps Ltd | Information & communication | 2024 |
| 52 AR Limited | Real estate | 2025 |
| 52 Arlingford Road Freehold Limited | Real estate | 2014 |
| 52 Balcombe Street (Freehold) Limited | Real estate | 2026 |
| 52 Bedford ROW Tenant Limited | Real estate | 2019 |
| 52 Belsize Park Limited | Real estate | 1987 |
| 52 Bickerton Road Freehold Company Limited | Real estate | 2024 |
| 52 Blenheim Road (Freehold) Limited | Households | 2023 |
| 52 Blomfield Road Limited | Households | 1982 |
| 52 Blue Ltd | Information & communication | 2022 |
| 52 Brecknock Road (Freehold) Ltd | Real estate | 2013 |
| 52 Bromar Road Limited | Households | 2019 |
| 52 Cavendish Freehold Company Limited | Households | 2026 |