| NOT Just Travel Limited | Administrative & support | 2003 |
| Novopro Fire Protection Ltd | Construction | 2025 |
| NOW Plans Ltd | Professional & scientific | 2017 |
| Number 1 Windows Ltd | Construction | 2016 |
| Nuntius Limited | Professional & scientific | 2001 |
| Nurs UK Barber Ltd | Other services | 2024 |
| Nurses ETC Limited | Administrative & support | 2010 |
| Nuvuw Ltd | Information & communication | 2016 |
| Nylo Homes (Poole) Limited | Construction | 2014 |
| Nylo Homes Limited | Construction | 2018 |
| Nylo Investments Limited | Real estate | 2020 |
| Nylo Studland Road Limited | Construction | 2021 |
| Oaka Vending (Dorset) Ltd | Hospitality | 2025 |
| Oaken Limited | Construction | 2019 |
| Oakfire Investments Limited | Wholesale & retail | 2014 |
| Oakhurst Freehold Limited | Households | 2018 |
| Oaklea Residents' Association Limited | Real estate | 1999 |
| Oakwood Counselling Ltd | Health & social care | 2025 |
| Oakwood Residents Association Limited | Households | 1999 |
| Ocean Sports Tuition Limited | Arts & recreation | 2005 |
| October Associates Limited | Professional & scientific | 2007 |
| Ocular Visuals Ltd | Information & communication | 2019 |
| Odin Consulting Group Ltd | Professional & scientific | 2026 |
| Odley Enough Investments Limited | Financial services | 2025 |
| Odyssey Gaming Ltd | Wholesale & retail | 2024 |
| OEM Outlet Limited | Extraterritorial | 2024 |
| Offshore Pro Ltd | Wholesale & retail | 2021 |
| Oils a Go Go Limited | Wholesale & retail | 2023 |
| Okoform Group Limited | Financial services | 2023 |
| Okoform IP Limited | Extraterritorial | 2021 |
| Okoform Limited | Other services | 2020 |
| Olliedog Properties Ltd | Real estate | 2022 |
| Olympusuk Ltd | Hospitality | 2019 |
| Olyvetree Ltd | Professional & scientific | 2014 |
| Omnilease Limited | Real estate | 1986 |
| ON the Layline Limited | Professional & scientific | 2023 |
| ON the Marque Limited | Administrative & support | 2021 |
| ON the Wave Business Advisory Ltd | Professional & scientific | 2026 |
| One Stop IT Services Ltd | Wholesale & retail | 2020 |
| Onesoul Ventures Limited | Wholesale & retail | 2026 |
| Only Holes and Patches Limited | Construction | 2022 |
| Onyx (Building Consultancy) LLP | | 2007 |
| Opal Data Limited | Information & communication | 1992 |
| Open House Bournemouth Ltd | Hospitality | 2020 |
| Opera Production Ltd | Other services | 2018 |
| Optima Management Systems Ltd | Professional & scientific | 2021 |
| Optimal Process Technology Limited | Professional & scientific | 2005 |
| Optimal Process Technology Trustee Ltd | Professional & scientific | 2026 |
| Optimartech Consulting Limited | Information & communication | 2025 |
| Orange Technology Limited | Education | 1997 |
| Orange-Learning Limited | Information & communication | 2020 |
| Orca Charters Ltd | Agriculture & fishing | 2026 |
| Orchard Homes (Southern) Ltd | Real estate | 2024 |
| Orchard Leigh Flat Management Company Limited | Households | 1984 |
| Orestes Gate (Mudeford) Residents Association Limited | Hospitality | 1989 |
| ORI Massage Therapy Limited | Health & social care | 2025 |
| Oriel Lodge Management Company Limited | Households | 1989 |
| Orions Revenge Ltd | Professional & scientific | 2019 |
| Orisveil Ltd | Wholesale & retail | 2026 |
| Orphir Limited | Construction | 2002 |
| OS Acoustics Ltd | Manufacturing | 2016 |
| Osamjok Company Ltd | Wholesale & retail | 2024 |
| Osprey Developments Southern Limited | Construction | 2020 |
| Ossemsley Manor Management Limited | Households | 1981 |
| Ottr Limited | Manufacturing | 2026 |
| Ovenmasters UK Ltd | Wholesale & retail | 2015 |
| Overt Digital Media Limited | Information & communication | 2020 |
| Ower Shooting Ground Ltd | Arts & recreation | 2013 |
| Oxford Capital Ltd | Financial services | 2021 |
| Oxford Central PCN Limited | Health & social care | 2025 |
| Oxford Consumer Accounts Ltd | Financial services | 2020 |
| Oxford Musculoskeletal Radiology LLP | | 2025 |
| Oxfords Property Holdings Limited | Financial services | 2020 |
| Oxro Ltd | Information & communication | 2019 |
| P D Lewis Consultancy Ltd | Administrative & support | 2021 |
| P&M Future Education Limited | Education | 2023 |
| P.D.I Doors Ltd | Construction | 2020 |
| P.O.D Hospitality & Leisure Ltd | Hospitality | 2021 |
| Pacific Edge Limited | Professional & scientific | 2019 |
| Padstow Harbour Hotel Limited | Hospitality | 2018 |
| Palm House Bournemouth Ltd | Hospitality | 2026 |
| Palmera World Exports Ltd | Extraterritorial | 2019 |
| Pamaro Technic Limited | Information & communication | 2015 |
| Pandemonium Records (Bournemouth) Limited | Wholesale & retail | 2022 |
| Parent Boost Ltd | Wholesale & retail | 2024 |
| Parentprep Ltd | Wholesale & retail | 2025 |
| Park Home Property Rentals Ltd | Real estate | 2024 |
| Parkcrest Construction Limited | Construction | 1998 |
| Parkview Global Trading Ltd | Professional & scientific | 2013 |
| Parley Manor Weddings Limited | Administrative & support | 2023 |
| Parnham Consulting Limited | Professional & scientific | 2019 |
| Paro Trading Ltd | Manufacturing | 2025 |
| Parrot Pandemonium Ltd | Agriculture & fishing | 2016 |
| Partly Group UK Branch | | 2022 |
| Pashcoll Precision Engineering Ltd | Manufacturing | 2025 |
| Patrick Bone Productions Limited | Arts & recreation | 2026 |
| Paul Garland Consulting Limited | Professional & scientific | 2023 |
| Paul Jackson Estate Agents Limited | Extraterritorial | 2015 |
| Paws Malone Publishing Limited | Information & communication | 2014 |
| PB Electrical Services Ltd | Manufacturing | 1997 |