| 129 Huddleston Road Management Company Limited | Households | 2017 |
| 129 KHR (Management) Limited | Real estate | 2018 |
| 129 Kilburn Lane Limited | Professional & scientific | 1997 |
| 129 Landor Road RTM Company Limited | Real estate | 2003 |
| 129 Marlborough Road Management Company Limited | Professional & scientific | 2003 |
| 129 Mercers Road Limited | Households | 2008 |
| 129 Mildmay Road Management Company Limited | Real estate | 2005 |
| 129 Newbridge Road (Bath) Limited | Extraterritorial | 1987 |
| 129 North Birkbeck Road Ltd | Real estate | 2025 |
| 129 North END Road Management Company Limited | Households | 2001 |
| 129 Palace Road Freehold Ltd | Households | 2022 |
| 129 Property Limited | Real estate | 2025 |
| 129 Thurleigh Road Limited | Households | 1980 |
| 129-130 Park Lane Management Limited | Households | 2006 |
| 129-135 Saunders Ness Road RTM Company Limited | Real estate | 2022 |
| 1290 Ltd | Real estate | 2024 |
| 1291 Group UK Ltd. | Financial services | 2002 |
| 1291 Ltd | Extraterritorial | 2021 |
| 1296 Ltd | Information & communication | 2023 |
| 12964805 Limited | Real estate | 2020 |
| 1297 Ltd | Real estate | 2025 |
| 129ERS Limited | Households | 2015 |
| 129SW Freehold Limited | Households | 2018 |
| 12:01 Group Ltd | Professional & scientific | 2026 |
| 12A Barnpark Terrace Limited | Real estate | 2009 |
| 12A Investments Ltd | Real estate | 2020 |
| 12A Penzance Place Limited | Households | 1998 |
| 12A Perrymead Street Limited | Households | 1997 |
| 12A Southey Street Management Co. Limited | Construction | 2008 |
| 12ACRES Cafe Limited | Hospitality | 2022 |
| 12ADVANCE Ltd | Real estate | 2024 |
| 12AGAIN Ltd. | Manufacturing | 2025 |
| 12AGC Ltd | Real estate | 2024 |
| 12AM Media Ltd | Professional & scientific | 2022 |
| 12B Solicitors Limited | Professional & scientific | 2019 |
| 12BE Limited | Extraterritorial | 2017 |
| 12BIT Media Ltd | Information & communication | 2026 |
| 12BOXES Limited | Professional & scientific | 2002 |
| 12D the Film Limited | Information & communication | 2023 |
| 12DESIGN UK Ltd | Wholesale & retail | 2018 |
| 12DIGITECH Ltd | Information & communication | 2026 |
| 12ECG.COM Limited | Education | 2025 |
| 12FOLD Studios Limited | Information & communication | 2025 |
| 12GP Management Limited | Professional & scientific | 2014 |
| 12HP Limited | Construction | 2021 |
| 12HUS Invest Limited | Extraterritorial | 2023 |
| 12HUS Limited | Extraterritorial | 2023 |
| 12NA Productions Ltd. | Information & communication | 2018 |
| 12NOTE Life Sciences Limited | Manufacturing | 2025 |
| 12ON12 Limited | Wholesale & retail | 2010 |
| 12PHS Limited | Households | 2016 |
| 12REPS Limited | Arts & recreation | 2024 |
| 12SG5 Limited | Real estate | 2024 |
| 12SIGMA Ltd | Professional & scientific | 2020 |
| 12STEPS Limited | Public administration | 2021 |
| 12STQ Ltd | Households | 2021 |
| 12TALENTS Limited | Information & communication | 2022 |
| 12TH Battalion Productions Limited | Information & communication | 2014 |
| 12TH Floor Studio Ltd | Professional & scientific | 2021 |
| 12TH MAN Ltd | Real estate | 2006 |
| 12TH MAN Talks Ltd | Wholesale & retail | 2021 |
| 12TH Player Ltd | Information & communication | 2019 |
| 12TH Search Ltd | Administrative & support | 2025 |
| 12TH Sourcing Ltd | Administrative & support | 2025 |
| 12TH Works Ltd | Professional & scientific | 2025 |
| 12TO4 Ltd | Wholesale & retail | 2020 |
| 12TOSIX Ltd | Wholesale & retail | 2022 |
| 12TRENT Ltd | Real estate | 2023 |
| 12VER Retail Ltd | Wholesale & retail | 2025 |
| 12X3 Aldgate Ltd | Arts & recreation | 2020 |
| 12Z Property Renovation Ltd | Real estate | 2024 |
| 13 Burma Road Management Limited | Households | 2007 |
| 13 - 18 Trojan CT Freehold Limited | Professional & scientific | 2023 |
| 13 Abbeville Road Management Limited | Households | 2006 |
| 13 Acre Agriculture Ltd | Agriculture & fishing | 2024 |
| 13 Adelaide Grove Management Company Limited | Households | 2003 |
| 13 Again LLP | | 2025 |
| 13 Albert Road Limited | Households | 2017 |
| 13 Alma Square Freehold Limited | Households | 2005 |
| 13 Amies Street Freehold Limited | Extraterritorial | 2015 |
| 13 Angles Road Limited | Households | 2004 |
| 13 Archel Road Limited | Real estate | 1995 |
| 13 Arlington Gardens Management Company Limited | Administrative & support | 1991 |
| 13 Arthur Road Freehold Limited | Households | 2020 |
| 13 Avenue Park Road Freehold Limited | Households | 2021 |
| 13 Avonmore Road RTM Company Ltd | Real estate | 2014 |
| 13 Balham Grove Limited | Households | 2020 |
| 13 Basing Street Freehold Company Limited | Households | 2008 |
| 13 Bassett Road Limited | Households | 2018 |
| 13 Belsize Grove Limited | Real estate | 1963 |
| 13 Blakesley Avenue Limited | Households | 2023 |
| 13 Blenheim Park Road Limited | Real estate | 2020 |
| 13 Bloemfontein Road Management Company Limited | Households | 2021 |
| 13 Bloom Grove Limited | Households | 2000 |
| 13 Bloomfield Road Management Company Limited | Households | 1992 |
| 13 Bolingbroke Grove (Freehold) Limited | Other services | 2002 |
| 13 Bolingbroke Grove Limited | Households | 1989 |
| 13 Bonchurch Road Management Limited | Real estate | 2002 |
| 13 Boyden House Ltd | Real estate | 2018 |
| 13 BP Limited | Households | 2002 |