| Reconnect Heating Services Ltd | Construction | 2019 |
| RECOVERYMR82 Limited | Transport & logistics | 2024 |
| Red Page Limited | Information & communication | 2009 |
| Redab Limited | Administrative & support | 1989 |
| Redab Office Limited | Construction | 2002 |
| Redmoor Interchange Management Limited | Extraterritorial | 2005 |
| Reeves Property Holdings Limited | Real estate | 2018 |
| Regean Limited | Real estate | 2014 |
| Reiths Hand Crafted Pine Furniture Limited | Manufacturing | 2002 |
| Release Global CIC | Health & social care | 2026 |
| Rescue My Company Limited | Real estate | 2015 |
| Restore and Move Physiotherapy Ltd | Health & social care | 2025 |
| Rework Kitchens Ltd | Manufacturing | 2024 |
| Reyna Brasserie Limited | Hospitality | 2008 |
| Riddell Lodge Flat Management Company Limited | Households | 2002 |
| Riddell Lodge Management Company Limited | Households | 2003 |
| Ridgeback Recruitment Resources Ltd | Professional & scientific | 2018 |
| Rivercam Communications Limited | Other services | 2014 |
| RJP Solutions (London) Ltd | Construction | 2022 |
| RKO London Limited | Administrative & support | 2023 |
| RNL Investments Limited | Real estate | 2021 |
| Rock Building & Basements Ltd | Construction | 2023 |
| Rockdove Distribution Ltd | Wholesale & retail | 2025 |
| Roman House Limited | Households | 1991 |
| Rook Roofing Ltd | Construction | 2018 |
| Roomsense Limited | Wholesale & retail | 2014 |
| Rose Look Ltd | Hospitality | 2013 |
| Rosedale Management Company (Andrews Lane) Limited | Real estate | 1986 |
| Rosedale Sports Club Limited | Arts & recreation | 2010 |
| ROSEKITCHEN27 Ltd | Hospitality | 2025 |
| Roslyn Supply Limited | Other services | 2001 |
| Runatap (Build and Travel Consultancy) Limited | Professional & scientific | 2010 |
| Rural Electrical Services Limited | Construction | 2022 |
| Rural Service Limited | Construction | 2010 |
| Rëgïnae Events Ltd | Administrative & support | 2025 |
| S & K Projects Limited | Construction | 2009 |
| S T Marsay Limited | Information & communication | 2023 |
| S&M Holiday Lets Limited | Hospitality | 2016 |
| S&S Consultants London Ltd | Professional & scientific | 2025 |
| Safi Kabisa Limited | Other services | 2020 |
| Salakantay Solutions Limited | Information & communication | 2011 |
| Sandford Road Management Company Limited | Households | 2009 |
| Saverine Quality Consultants Limited | Professional & scientific | 2016 |
| SBH Construction Group Ltd | Construction | 2017 |
| SC General Services Limited | Administrative & support | 2008 |
| Scissors Hair Studio Limited | Other services | 2008 |
| Scrivt Limited | Information & communication | 2024 |
| Searchful Ltd | Wholesale & retail | 2017 |
| Sewardstone Nursery Limited | Wholesale & retail | 2003 |
| Sharp Creative Limited | Professional & scientific | 2016 |
| Shrewness Lettings Limited | Hospitality | 2025 |
| Shuban Estate Limited | Real estate | 2026 |
| Shuban Housing Limited | Real estate | 2026 |
| Shuban Property Development Limited | Real estate | 2024 |
| Sixth Northall Housing Management Company Limited | Households | 1981 |
| SJ Arborists Limited | Agriculture & fishing | 2026 |
| Skin by Ecem Limited | Other services | 2022 |
| Skylong Productions Ltd | Professional & scientific | 2017 |
| Small Fries Games Limited | Manufacturing | 2015 |
| Smart Life Estates Limited | Real estate | 2005 |
| Smart Life Properties Ltd | Real estate | 2025 |
| Smart Perfection Limited | Wholesale & retail | 2014 |
| Smith & Marshall Ltd | Real estate | 2017 |
| Smyth Hamilton Limited | Information & communication | 2014 |
| Sodens Limited | Information & communication | 2011 |
| Solazzo & Co Limited | Professional & scientific | 2001 |
| Somewhere Different Bakery Ltd | Manufacturing | 2021 |
| Songhai Lettings Ltd | Real estate | 2010 |
| Sonicfone Ltd | Information & communication | 2019 |
| South East Construction Limited | Construction | 1982 |
| Sparrows Herne Management Co. Limited | Households | 2005 |
| Sparta Insurance Services Group Limited | Financial services | 2017 |
| Spectrum Insurance Holdings Limited | Financial services | 2001 |
| Spraytech Auto Body Centre Limited | Wholesale & retail | 2019 |
| SS & BS Property Investment (UK) Ltd | Real estate | 2014 |
| ST Mary's CE Academy, Cheshunt | Education | 2012 |
| Stableside Limited | Professional & scientific | 2017 |
| Star Wharf Residents Management Company Limited | Households | 2006 |
| Stars Gym Club Ltd | Education | 2008 |
| Starview Lofts & Extensions Ltd | Construction | 2019 |
| Sterling & Law Hertford Limited | Financial services | 2001 |
| Stevall Ltd | Health & social care | 2024 |
| Steve Cable Limited | Administrative & support | 2016 |
| STR Motorcycles Repairs Limited | Wholesale & retail | 2024 |
| STS Motors & Forwarding Ltd | Wholesale & retail | 2015 |
| STUDIO26 Interiors Ltd | Professional & scientific | 2025 |
| Sunley Communications Limited | Information & communication | 2004 |
| Sunnah Vision Ltd | Wholesale & retail | 2018 |
| Sunney Sports Surfaces Ltd | Administrative & support | 2024 |
| Supaclean (Herts) Limited | Other services | 2011 |
| Supervan Limited | Administrative & support | 2000 |
| SW3 Design & Build Ltd | Construction | 2015 |
| Sweetings (City) Limited | Hospitality | 1956 |
| Swissedent Limited | Health & social care | 1994 |
| Synergy Prestige Limited | Administrative & support | 2016 |
| Tanfield Farm Residents Company (2) Ltd | Households | 2019 |
| Tanfield Farm Residents Company Ltd | Households | 2005 |
| Tass Enterprise Limited | Other services | 2010 |
| TC Solutions Ltd | Information & communication | 2025 |
| TDS Safeguard (London) Limited | Information & communication | 2015 |