| RMV Paving Ltd | Construction | 2024 |
| RNB Republic National Bank of New York (Suisse) S.A. | | 1994 |
| Rnns Developments Ltd | Real estate | 2021 |
| Rnrs Only Limited | Information & communication | 2003 |
| RNS Business Solutions Limited | Professional & scientific | 2003 |
| RNS Trading Limited | Information & communication | 1998 |
| Roastlake Limited | Households | 1987 |
| ROB Benn Consultancy Ltd | Professional & scientific | 2026 |
| ROB Bliss Limited | Information & communication | 2013 |
| ROB Varcoe Consulting Ltd | Professional & scientific | 2016 |
| Robert Clow & Co Limited | Professional & scientific | 2002 |
| Robert Jones | | 1998 |
| Robert. Bundy | | 1998 |
| Roberto Palmer Interiors Ltd | Other services | 2014 |
| Robin Bryson Limited | Professional & scientific | 2004 |
| Robo Publishing Limited | Information & communication | 1998 |
| Rocca Rossa Limited | Construction | 2007 |
| Rock Electronics Limited | Wholesale & retail | 2000 |
| Rock'D UP Clothing Ltd | Wholesale & retail | 2025 |
| Rockley Dene Homes Limited | Health & social care | 1987 |
| Rodfri Enterprises Ltd | Administrative & support | 2016 |
| Rolingo Ltd | Information & communication | 2024 |
| Rolitex Limited | Administrative & support | 1995 |
| Romaec-Tol Care Services Limited | Professional & scientific | 2009 |
| Romana Court Residents Association Limited | Households | 1987 |
| Rootstock Insight Ltd | Professional & scientific | 2007 |
| Ropemaker Deansgate Limited | Administrative & support | 2001 |
| Ropemaker Properties Limited | Administrative & support | 1963 |
| Rose Pharma Ltd | Health & social care | 2024 |
| Rosebells Limited | Real estate | 1998 |
| Rosh Pinah Jewish Primary School Trust | Education | 2000 |
| Rothbury Consultants Limited | Professional & scientific | 1998 |
| Rothel (UK) Limited | Wholesale & retail | 1987 |
| Roundmills Limited | Real estate | 1987 |
| Route LIP Ltd | Construction | 2025 |
| Routeene (UK) Limited | Real estate | 1991 |
| Roxborough Park Limited | Real estate | 1991 |
| Roxbourne Press Limited | Manufacturing | 2003 |
| ROY Thomson Limited | Construction | 2003 |
| RS Contracts Ltd. | Administrative & support | 1999 |
| RSD Cars Limited | Wholesale & retail | 2006 |
| RSM Construction Ltd | Other services | 2000 |
| RSP Trading Limited | | 1999 |
| RT Executives Ltd | Transport & logistics | 2014 |
| RTT Programmes Limited | Professional & scientific | 1998 |
| Ruby's Food & Wine Ltd | Wholesale & retail | 2001 |
| Ruby's Food Products Ltd | Wholesale & retail | 2005 |
| Rudav Limited | Real estate | 1960 |
| Rufair Limited | Health & social care | 2015 |
| Rufford Close Kenton Management Limited | Households | 2002 |
| Ruislip Cars Limited | Transport & logistics | 2020 |
| Ruislip Hand Car Wash Ltd | Real estate | 2016 |
| Ruislip Kitchens Limited | Manufacturing | 2018 |
| Ruislip Plant Limited | Manufacturing | 1982 |
| Rupesh Shah Aesthetics Ltd | Health & social care | 2020 |
| Rushton Enterprises Limited | Real estate | 1983 |
| Russell Court (Purley) Management Limited | Households | 1986 |
| Russell Finex Limited | Manufacturing | 1934 |
| Russell-Hurst Trustees Limited | Financial services | 1961 |
| Russell. Riggs | | 1998 |
| Rusuk Ltd | Real estate | 1999 |
| Ruthless Media Limited | Professional & scientific | 2003 |
| RVE Capital LLP | | 2021 |
| Rxmedia Ltd | Information & communication | 2006 |
| Ryan James Property Limited | Real estate | 2015 |
| Ryan Wood Studio Limited | Arts & recreation | 2008 |
| Ryland & Co Ltd | Professional & scientific | 2001 |
| S & F Stafflink Limited | Professional & scientific | 2001 |
| S & H Property Management Ltd | Real estate | 2007 |
| S & S Consultancy Services Limited | Real estate | 2000 |
| S & S Khan Limited | Real estate | 1993 |
| S & S Pharmacy Limited | Wholesale & retail | 2002 |
| S & S Properties London LLP | | 2013 |
| S a B Securities Limited | Financial services | 2003 |
| S C (Wealdstone) Limited | Households | 1972 |
| S R Construction (London) Limited | Construction | 2004 |
| S R Decorations Limited | Wholesale & retail | 1990 |
| S S Fuel Stops Limited | Wholesale & retail | 2005 |
| S Tailoring Ltd | Administrative & support | 2023 |
| S&A Services Ltd | Professional & scientific | 2000 |
| S&A Son's Property Ltd | Real estate | 2023 |
| S&J Construction Services Limited | Construction | 2007 |
| S-Logibis (UK) Ltd | Wholesale & retail | 2000 |
| S. Chowdhury & Co Limited | Professional & scientific | 2002 |
| S. Leonard Plant Hire & Haulage Limited | Construction | 2004 |
| S. R. Associates Limited | Professional & scientific | 1997 |
| S. R. Kipps & Sons Limited | | 1980 |
| S.A.T.V. Publishing Limited | Professional & scientific | 1972 |
| S.B.Weston Limited | Manufacturing | 1964 |
| S.H. Harrold (1937) Limited | Wholesale & retail | 1978 |
| S.J. Clarke Associates Limited | Professional & scientific | 2007 |
| S.J.H. Consultants Limited | Professional & scientific | 1989 |
| S.J.M. Europe Limited | Wholesale & retail | 2001 |
| S.K. Management Consultants Limited | Professional & scientific | 1996 |
| S.M.A.C. (UK) Limited | Construction | 2005 |
| S.O. Steel Construction Garden Rooms and Loft Extensions Limited | Construction | 2024 |
| S.P.B. (Building Contractors) Limited | Construction | 1986 |
| S.R. Enterprises (UK) Limited | Other services | 2005 |
| S.R.E. Corporation Limited | Administrative & support | 2000 |
| S.S.S.Clutch Company Limited | Professional & scientific | 1955 |