| Slough Building Centre Limited | Real estate | 1985 |
| Slough Building Services Ltd | Construction | 2023 |
| Slough Business Community Partnership | Professional & scientific | 2001 |
| Slough Business Park Ltd | Real estate | 2016 |
| Slough Capital Ltd | Financial services | 2023 |
| Slough Car Hire Ltd | Wholesale & retail | 2016 |
| Slough Care in Home Ltd | Health & social care | 2021 |
| Slough Care Limited | Health & social care | 2014 |
| Slough Cars and Vans Ltd | Wholesale & retail | 2024 |
| Slough Catering Limited | Hospitality | 2022 |
| Slough Ceramics Limited | Wholesale & retail | 2004 |
| Slough Chamber of Commerce Limited | Other services | 2011 |
| Slough Chicken & Pizzas Ltd | Hospitality | 2025 |
| Slough Children First Limited | Health & social care | 2015 |
| Slough City Investments Limited | Real estate | 2022 |
| Slough City Real Estates Limited | Real estate | 2020 |
| Slough Cleaning Services Ltd | Administrative & support | 2019 |
| Slough Communications Limited | Wholesale & retail | 2013 |
| Slough Community Transport & Shopmobility | Transport & logistics | 2002 |
| Slough Construction Ltd | Construction | 2024 |
| Slough Consultancy Ltd | Professional & scientific | 2024 |
| Slough Cottage Limited | Hospitality | 2020 |
| Slough Crossroads - Caring for Carers | Health & social care | 2002 |
| Slough Dadyal Halal Meat Ltd | Wholesale & retail | 2023 |
| Slough Driving Ltd | Education | 2025 |
| Slough Driving School Ltd | Education | 2023 |
| Slough Electric & Hybrid Cars Specialist Ltd | Wholesale & retail | 2019 |
| Slough Electrician Ltd | Construction | 2020 |
| Slough Faith Partnership Limited | Education | 2011 |
| Slough Fish Bar Ltd | Hospitality | 2024 |
| Slough Food & Wine Ltd | Wholesale & retail | 2025 |
| Slough Foods Ltd | Wholesale & retail | 2018 |
| Slough German Doner Ltd | Hospitality | 2025 |
| Slough Halal Meat & Co Ltd | Wholesale & retail | 2019 |
| Slough Halal Meat & Grocery Ltd | Wholesale & retail | 2026 |
| Slough Halalyum Meatry Limited | Wholesale & retail | 2024 |
| Slough Healthcare Limited | Extraterritorial | 2015 |
| Slough Hidaya Centre (SHC) | Other services | 2010 |
| Slough Homepro Ltd | Administrative & support | 2025 |
| Slough I G Limited | Hospitality | 2012 |
| Slough Islamic School Project Ltd | Education | 2025 |
| Slough Locc PCN Ltd | Health & social care | 2023 |
| Slough Luxe Restaurant Ltd | Hospitality | 2024 |
| Slough Marquees Ltd | Administrative & support | 2019 |
| Slough Martial Arts Promotions Limited | Arts & recreation | 2003 |
| Slough Masonic Hall Company Limited | Other services | 1961 |
| Slough Mitra Mandal Ltd. | Arts & recreation | 2012 |
| Slough Mobiles Hub Ltd | Wholesale & retail | 2020 |
| Slough Mobiles Ltd | Information & communication | 2020 |
| Slough Modest Sisters CIC | Education | 2020 |
| Slough Motor Cars Ltd | Wholesale & retail | 2024 |
| Slough Motor Trade Limited | Wholesale & retail | 2022 |
| Slough Museum | Arts & recreation | 2000 |
| Slough Muslim College CIC | Other services | 2025 |
| Slough Old Library Hotels Ltd | Hospitality | 2017 |
| Slough Pet Friend Ltd | Other services | 2016 |
| Slough Pigeons Feed Ltd | Other services | 2021 |
| Slough Plumbing & Plastic Centre Ltd | Wholesale & retail | 2025 |
| Slough Quality Fish Ltd | Wholesale & retail | 2015 |
| Slough Real Estate Ltd | Real estate | 2024 |
| Slough Rubbish Clearance Limited | Water & waste | 2015 |
| Slough School for Arabic & Islamic Studies | Education | 2010 |
| Slough Scooter Ltd | Wholesale & retail | 2024 |
| Slough Society for Mentally Handicapped Children and Adults | Health & social care | 2006 |
| Slough Streetfood Limited | Administrative & support | 2016 |
| Slough Tabletop Collective Limited | Arts & recreation | 2025 |
| Slough Tamil Sangamam CIC | Arts & recreation | 2022 |
| Slough Town Centre BID Ltd | Administrative & support | 2019 |
| Slough Town Junior Football Club Limited | Arts & recreation | 2017 |
| Slough Traders Ltd | Wholesale & retail | 2019 |
| Slough Trading Estate Business Watch Limited | Administrative & support | 1994 |
| Slough Trading Ltd | Wholesale & retail | 2026 |
| Slough Travel Ltd | Administrative & support | 2018 |
| Slough Tuition Centre Limited | Education | 2014 |
| Slough Tyre Centre Ltd | Wholesale & retail | 2014 |
| Slough UK Assets Ltd | Real estate | 2023 |
| Slough UK Properties Ltd | Real estate | 2021 |
| Slough West Indian Peoples Enterprise (S.W.I.P.E.) Ltd | Education | 1999 |
| Slumball Run Ltd | Administrative & support | 2019 |
| SM & Sons Ltd | Hospitality | 2022 |
| SM Agile Consulting Limited | Professional & scientific | 2017 |
| SM Appliance Repair Services Limited | Manufacturing | 2026 |
| SM Motor Trade Limited | Wholesale & retail | 2025 |
| SM Private Hire Ltd | Transport & logistics | 2023 |
| SM Property Consultants Limited | Construction | 2014 |
| SM Services (Slough) Limited | Wholesale & retail | 2014 |
| SM Wealth Group Limited | Real estate | 2019 |
| SM Wealth Management Ltd | Real estate | 2023 |
| SM World Limited | Real estate | 2019 |
| SMA Finance Limited | Financial services | 2026 |
| Small & Co Furniture Paint Ltd | Wholesale & retail | 2023 |
| Small Car Leasing Ltd | Administrative & support | 2020 |
| Smart A/C Solutions Ltd | Construction | 2019 |
| Smart and Modern Homes (Berkshire) Ltd | Construction | 2026 |
| Smart Assets Management Ltd | Real estate | 2022 |
| Smart Business Solutions Ltd | Information & communication | 2021 |
| Smart Cafe Catering Ltd | Hospitality | 2025 |
| Smart Cars Berkshire Ltd | Transport & logistics | 2025 |
| Smart Cart Hub Ltd | Wholesale & retail | 2025 |
| Smart Chauffeurs London Limited | Transport & logistics | 2019 |