| Oriental Leisure Ltd | Other services | 2015 |
| Oriental Tasty Ltd | Hospitality | 2025 |
| Origen Power Ltd | Professional & scientific | 2013 |
| Original Items UK Limited | Wholesale & retail | 2025 |
| Orion Logistics Ltd | Transport & logistics | 2020 |
| Orion Miniature Painting Studio Limited | Other services | 2013 |
| Orionisuk Ltd | Information & communication | 2023 |
| Orka Group Ltd | Manufacturing | 2020 |
| Ornixa Ltd | Professional & scientific | 2020 |
| Ortho Keep Smiling Limited | Health & social care | 2014 |
| Orthosky UK Ltd | Health & social care | 2020 |
| ORU Homma Ltd | Manufacturing | 2024 |
| Orvion Digital Ltd | Information & communication | 2026 |
| OSB Limited | Construction | 2026 |
| Osho Construction Limited | Construction | 2025 |
| Osis Skin Ltd | Wholesale & retail | 2019 |
| Osmanthus Ltd | Professional & scientific | 2023 |
| OT Trends Limited | Wholesale & retail | 2020 |
| OTR Promotions Ltd | Wholesale & retail | 2019 |
| OTS Finishes Limited | Construction | 2020 |
| Otuntech Ltd | Wholesale & retail | 2024 |
| OUD Matters Ltd | Wholesale & retail | 2025 |
| OUR Family Care Home Limited | Health & social care | 2018 |
| OUR Special Angels Send CIC | Health & social care | 2024 |
| Ournet Health Services Ltd | Health & social care | 2019 |
| Ours Construction Ltd | Construction | 2026 |
| Outfitofthenight Ltd | Wholesale & retail | 2019 |
| Outspire Nova Limited | Wholesale & retail | 2025 |
| Overcoast Music Limited | Information & communication | 2012 |
| Overwatch Cctv & Security Ltd | Administrative & support | 2021 |
| Owen Installations Ltd | Construction | 2007 |
| Owen Nash Limited | Professional & scientific | 2026 |
| Owlet Properties Limited | Real estate | 2023 |
| Owutech Machine Tools Limited | Manufacturing | 2019 |
| Oxbridge College Selector Limited | Education | 2021 |
| Oxford Medical Knowledge Limited | Health & social care | 1998 |
| OZA Consultancy Ltd | Professional & scientific | 2024 |
| Ozim Limited | Wholesale & retail | 2023 |
| Ozone Efficiency Ltd | Water & waste | 2015 |
| P & a Phoenix Properties Ltd | Real estate | 2023 |
| P & D Group Services Limited | Manufacturing | 1987 |
| P & D Plastering & Building Services Ltd | Construction | 2000 |
| P & P Dhanda Properties Limited | Real estate | 2016 |
| P & R Projects (Midlands) Limited | Construction | 2007 |
| P & S Scaffolding Limited | Construction | 2012 |
| P & Tech Solution Limited | Manufacturing | 2024 |
| P & W Plastering Ltd | Construction | 2003 |
| P a Gough Painting Contractors Limited | Professional & scientific | 2003 |
| P C Accountancy Limited | Professional & scientific | 2017 |
| P C Autos Midlands Ltd | Wholesale & retail | 2025 |
| P E M Cowdy Limited | Real estate | 2003 |
| P G Hopkins Decorating Services Limited | Construction | 2004 |
| P Gill Trimming Limited | Administrative & support | 2016 |
| P H Industrial Services Limited | Construction | 2001 |
| P L Builders & Plumbers Limited | Construction | 2020 |
| P M Window Services Limited | Construction | 2020 |
| P R M Builders Limited | Construction | 2014 |
| P R M Builders Walsall Ltd | Construction | 2022 |
| P R Walker Carpentry Services Limited | Construction | 2021 |
| P Reynolds Recovery & Haulage Limited | Wholesale & retail | 2024 |
| P S Builder Midlands Ltd | Construction | 2018 |
| P S Joyce Limited | Construction | 2009 |
| P S L Property Services Ltd | Construction | 2005 |
| P S Landscaping Ltd | Administrative & support | 2022 |
| P&B Fusion Food Ltd | Hospitality | 2026 |
| P&J Enterprises Ltd | Wholesale & retail | 2011 |
| P&J Investment Properties Limited | Real estate | 2018 |
| P&P Building & Electrical Services Ltd | Construction | 2016 |
| P&P Day Nursery Limited | Health & social care | 2024 |
| P. & E. Harrington Plant Hire Limited | Construction | 1975 |
| P. Gratton Limited | Hospitality | 2011 |
| P. Taylor & Sons (Building Consultants) Limited | Construction | 2018 |
| P.A.G Investments Ltd | Extraterritorial | 2014 |
| P.C. Bryan Ltd | Real estate | 2024 |
| P.C. Harrington Holdings Limited | Financial services | 1991 |
| P.C. Harrington Limited | Construction | 2002 |
| P.J Quinn Property Ltd | Households | 2025 |
| P.S Delivered Ltd | Manufacturing | 2013 |
| P1M1U1 Medical Ltd | Health & social care | 2022 |
| P4P Boxing Academy Walsall Ltd | Arts & recreation | 2025 |
| P8 Limited | Information & communication | 2005 |
| P87 Lakeside Limited | Real estate | 2024 |
| PA Carpentry Limited | Construction | 2011 |
| PA Technologies Limited | Financial services | 2012 |
| Pabla Property Ltd | Real estate | 2024 |
| Pacesoft Limited | Information & communication | 1987 |
| Pacific SL Holdings Ltd | Manufacturing | 2015 |
| Pacific Sound and Light Limited | Manufacturing | 1998 |
| Pack Nest Business Solution Ltd | Wholesale & retail | 2025 |
| Paddle 'N' Swim School Ltd | Education | 2024 |
| Paddock Blade Industries Ltd | Manufacturing | 2020 |
| Paddock Electrical & Installations Limited | Construction | 2017 |
| Padel Club Leisure Ltd | Hospitality | 2026 |
| Padel Co Group Limited | Arts & recreation | 2025 |
| Paeon Injury and Fitness Ltd | Other services | 2015 |
| Paie Services Limited | Construction | 2024 |
| Paig Limited | Other services | 2017 |
| Painter & Partners Ltd | Professional & scientific | 2025 |
| Paiqi Limited | Hospitality | 2020 |
| Paisley Care Ltd | Public administration | 2024 |