| Roebuck Land and Planning Ltd | Other services | 2019 |
| Roger Lascelles Clocks Limited | Administrative & support | 2008 |
| ROK Barbers Ltd | Other services | 2023 |
| ROK Barbers WC Ltd | Other services | 2017 |
| Rokk and Rose Limited | Real estate | 2023 |
| Rokproducts Ltd | Wholesale & retail | 2019 |
| Rolec (Data Cabling) Limited | Professional & scientific | 1997 |
| Rolec (Electrical & Mechanical Services) Limited | Construction | 1982 |
| Rolec (Mechanical Services) Limited | Extraterritorial | 1989 |
| Rolec (Tickford) Limited | Construction | 2018 |
| Rolec Holdings Limited | Construction | 2018 |
| Rose Gold Fitness Ltd | Arts & recreation | 2020 |
| Rosehill Music Publishing Company Limited | Information & communication | 1977 |
| Ross Stone Carpentry Limited | Manufacturing | 2023 |
| Rotech Machines Limited | Manufacturing | 1997 |
| Rowelane Group Limited | Financial services | 2025 |
| Rowelane Homes Ltd | Real estate | 2024 |
| Royco Homes Limited | Construction | 2009 |
| Royle Brickwork Limited | Construction | 2012 |
| RPG Investments Ltd | Financial services | 2017 |
| RPG Property Investments Ltd | Real estate | 2017 |
| Rrr-Nb Property Holdings Ltd | Real estate | 2025 |
| RT Solar Limited | Construction | 2021 |
| Russel Business Solutions Limited | Hospitality | 2010 |
| Rwmw Projects Ltd | Professional & scientific | 2026 |
| S & a Property Developers Limited | Real estate | 2013 |
| S B & Associates Ltd | Administrative & support | 2013 |
| S Digital Limited | Information & communication | 2012 |
| S&D Logistics Ltd | Transport & logistics | 2019 |
| S&G Fencing and Landscaping Ltd | Administrative & support | 2026 |
| S.R. Osborn & SON Limited | Manufacturing | 2000 |
| Saav Restaurants Limited | Hospitality | 2019 |
| Sadhana Arts CIC | Arts & recreation | 2025 |
| Safety Associates Limited | Professional & scientific | 2018 |
| Saho Drink UK Ltd | Wholesale & retail | 2025 |
| Salesflow Marketing Limited | | 1986 |
| Salex Studio Liner Limited | Construction | 2024 |
| Sameli Ltd | Construction | 2016 |
| Sanal Beauty Ltd | Wholesale & retail | 2025 |
| Sandringham Communications Limited | Extraterritorial | 2013 |
| Sarah Hall Nutrition Ltd | Health & social care | 2021 |
| Sarah Tite Coaching Limited | Professional & scientific | 2022 |
| Sash Window Restoration Winslow Limited | Construction | 2018 |
| Saxon Footcare Limited | Health & social care | 2019 |
| Saxons Consulting Limited | Information & communication | 2018 |
| SAY IT Forever Ltd | Information & communication | 2023 |
| SB Installations Ltd | Financial services | 2026 |
| SBM Advisory Ltd | Professional & scientific | 2015 |
| Scaleforge Consulting Ltd | Professional & scientific | 2026 |
| Scarlet Rose Tattoo Ltd | Other services | 2026 |
| School Supplyline Limited | Extraterritorial | 2000 |
| Scoop Designs Limited | Extraterritorial | 1987 |
| Sdmi Ltd | Real estate | 2023 |
| Sdmi One Ltd | Real estate | 2024 |
| Seasons Art Class, Milton Keynes Limited | Education | 2018 |
| Secure Financial Planning Ltd | Financial services | 2024 |
| Securycor Limited | Administrative & support | 2023 |
| Selham Court Management Company (One) Limited | Households | 2002 |
| Selltow Consultancy Limited | Administrative & support | 2012 |
| Sensory Connections Therapy and Assessment Services Limited | Education | 2025 |
| Senzsi Africa Ltd | Wholesale & retail | 2019 |
| Septic Tank Warehouse Ltd | Wholesale & retail | 2016 |
| SET in Stone Investments Ltd | Real estate | 2025 |
| Sevenhills Property Services Ltd | Real estate | 2020 |
| SFB Carpentry Ltd | Construction | 2025 |
| SG Corporate Limited | Construction | 2022 |
| SGS Tyre Services Limited | Wholesale & retail | 2023 |
| Shake a Shake Holding Ltd | Hospitality | 2022 |
| Shakti Estates Ltd | Real estate | 2016 |
| Sharp Concepts Limited | Manufacturing | 2013 |
| Sharp Masonry Limited | Construction | 2025 |
| Shasva Convenience Store Ltd | Wholesale & retail | 2024 |
| Shed 37 Barbers Ltd | Other services | 2018 |
| Shenzhen China TEX Industry Co (UK) Ltd | Manufacturing | 2019 |
| Sheppards Close Management Company Limited | Households | 2017 |
| Shieldtech Installations Ltd | Construction | 2026 |
| Shift & Scale Limited | Professional & scientific | 2025 |
| Shore Plant Ltd | Construction | 2023 |
| Showtime Exhibitions Ltd | Professional & scientific | 2010 |
| Sicily Unlimited Limited | Administrative & support | 2014 |
| Signature Period Properties Ltd | Construction | 2026 |
| Signature Quality Refurbished Homes Limited | Construction | 1994 |
| Silk Edits Limited | Information & communication | 2016 |
| Sills Performing Arts Academy Ltd | Education | 2017 |
| Silver Plate Services Limited | Hospitality | 2024 |
| Simaq Limited | Information & communication | 2025 |
| Simona's Cafe Limited | Hospitality | 2025 |
| Simple Van & Truck Hire Limited | Administrative & support | 2007 |
| Simply Plumbing and GAS Services Ltd | Construction | 2023 |
| Simpsing Limited | Professional & scientific | 2016 |
| Sircl Limited | Professional & scientific | 2019 |
| Site Plant Servicing Ltd | Water & waste | 2024 |
| Sitem Solutions Ltd | Administrative & support | 2019 |
| SJA Live Ltd | Information & communication | 2025 |
| Sjhr Investments Ltd | Real estate | 2025 |
| SJS Home Improvements Ltd. | Administrative & support | 2007 |
| SK Bhogal Properties Ltd | Real estate | 2025 |
| Skintech Adhesives Ltd | Professional & scientific | 2020 |
| Sky Boat Productions Ltd | Administrative & support | 2021 |
| Skylift Engineering Limited | Manufacturing | 2019 |