| Oates Rural Ltd | Professional & scientific | 2022 |
| Occupational Medical Services (Sheffield) Limited | Health & social care | 1987 |
| Occupational Medical Services Limited | Health & social care | 1993 |
| OGR Offshore Ltd | Manufacturing | 2023 |
| Old Rectory Howick Limited | Hospitality | 2017 |
| Old School Gallery Ltd | Wholesale & retail | 2014 |
| Olive Tree International Limited | Professional & scientific | 2022 |
| Omnia Coria (Alnwick) Ltd | Wholesale & retail | 2025 |
| One Day Properties Limited | Real estate | 2023 |
| One Integrity Limited | Professional & scientific | 2020 |
| Osmai Limited | Professional & scientific | 2018 |
| Oswalds of Bamburgh Ltd | Wholesale & retail | 2024 |
| Own IT Studios Ltd | Professional & scientific | 2024 |
| P J Brown (Building Contractors) Limited | Construction | 2007 |
| P Kell Trading Limited | Manufacturing | 2014 |
| P. Dawson Developments Limited | Construction | 2010 |
| PAN Haven Limited | Hospitality | 2022 |
| PAN Rocks Limited | Hospitality | 2022 |
| Parkhouse Farm Limited | Extraterritorial | 2013 |
| Patilly Productions Ltd | Arts & recreation | 2017 |
| Paul Foster Stonemason & Builder Limited | Construction | 2019 |
| Paul Heatley Writing Ltd | Information & communication | 2024 |
| Paul Willis Bloodstock Ltd | Agriculture & fishing | 2026 |
| Penn Gallery Ltd | Wholesale & retail | 2017 |
| Penny Bakery UK Limited | Manufacturing | 2022 |
| Penny Forecourts Limited | Financial services | 2025 |
| Penny Group Investments Limited | Financial services | 2025 |
| Penny Hotels UK Limited | Hospitality | 2022 |
| Penny on the Move (UK) Limited | Wholesale & retail | 2022 |
| Penny on the Move Limited | Wholesale & retail | 2022 |
| Penny Petroleum ( Topspot) Ltd | Financial services | 2013 |
| Penny Petroleum (GB) Limited | Wholesale & retail | 2022 |
| Penny Petroleum (Management) Limited | Wholesale & retail | 2012 |
| Penny Petroleum (North East) Limited | Wholesale & retail | 2012 |
| Penny Petroleum (Scarborough) Limited | Wholesale & retail | 2009 |
| Penny Petroleum (Scotland) Limited | Wholesale & retail | 2011 |
| Penny Petroleum (ST. Helens) Limited | Wholesale & retail | 2010 |
| Penny Petroleum (UK) Limited | Wholesale & retail | 2022 |
| Penny Petroleum LLP | | 2012 |
| Pentimento Productions Ltd | Other services | 2021 |
| Peppermoor Farm Limited | Hospitality | 2021 |
| Percy Green Batt Limited | Households | 2024 |
| Perfect Attendance Ltd | Hospitality | 2020 |
| Perfect Meadows Ltd | Administrative & support | 2022 |
| Peritus IT Solutions Limited | Information & communication | 2014 |
| Perre Limited | Real estate | 2024 |
| Phelan Independent Limited | Professional & scientific | 2020 |
| Phelan Independent Properties UK Limited | Real estate | 2023 |
| Pickard Electricals Limited | Construction | 1999 |
| Pierce Law Limited | Professional & scientific | 2019 |
| PIG in Muck Limited | Hospitality | 2020 |
| Pinfold Maintenance Company Limited | Real estate | 2000 |
| Pizza Royale Alnwick Ltd | Hospitality | 2023 |
| Platform Padel Limited | Arts & recreation | 2025 |
| Portaplan Limited | Households | 1988 |
| Potts Environmental Restoration Limited | Administrative & support | 2026 |
| PR Alnwick Ltd | Hospitality | 2024 |
| Prestige Car Direct Properties 2 Ltd | Real estate | 2018 |
| Pretty Serendipity Limited | Manufacturing | 2018 |
| Primacy Health Limited | Health & social care | 2019 |
| Primrose's Patisserie Limited | Wholesale & retail | 2025 |
| Pritchard Labs Ltd | Information & communication | 2022 |
| Pro-Tactics Limited | Professional & scientific | 2004 |
| Property Measure Limited | Real estate | 2022 |
| Property Planning Ltd | Real estate | 2022 |
| Propology Boutique Property Consultants Limited | Real estate | 2013 |
| Prudhoe Storage Solutions Limited | Administrative & support | 2024 |
| Psas Projects Ltd | Other services | 2013 |
| Psychological Services for Health Ltd | Health & social care | 2024 |
| Public Offerings Ltd | Professional & scientific | 2019 |
| Puffin Enterprises Limited | Wholesale & retail | 2013 |
| Pure Pave Resin Surfaces Ltd | Construction | 2025 |
| Purple Orange (Northumberland ) Limited | Hospitality | 2012 |
| Pyeroom Ltd | Hospitality | 2025 |
| Quest Inventory Ltd | Manufacturing | 2024 |
| R & S Armstrong Ltd | Other services | 2023 |
| R H Fell Limited | Professional & scientific | 2015 |
| R J Shell Ltd | Hospitality | 2014 |
| R Scott Properties Limited | Administrative & support | 2018 |
| R Stuart Services Ltd | Administrative & support | 2019 |
| R Y Electrical Limited | Construction | 2004 |
| R&S Builders (North East) Limited | Construction | 2019 |
| R. Ellis Stonemason and Builder Limited | Construction | 2019 |
| R. Turnbull & Sons Ltd. | Wholesale & retail | 1992 |
| R.F.G (UK) Ltd | Arts & recreation | 2011 |
| R.S. Anderson Homes Limited | Real estate | 2024 |
| Rackerman Limited | Wholesale & retail | 2023 |
| Rafi & Sons Ltd | Wholesale & retail | 2016 |
| Rafi Real Estate Limited | Real estate | 2021 |
| RB Interiors North East Ltd | Construction | 2024 |
| RCC Electrical Ltd | Professional & scientific | 2019 |
| RDA Brewis Properties Ltd | Real estate | 2025 |
| Rdfj Ltd | Construction | 2021 |
| Real Fitness Enterprises Limited | Arts & recreation | 2014 |
| Real Strength Enterprises Limited | Arts & recreation | 2021 |
| Real Wellness Enterprises Ltd | Other services | 2021 |
| Recocoa Ltd | Other services | 2019 |
| Red House Wind Limited | Real estate | 2012 |
| Red Lion Cottages Glanton Northumberland Limited | Households | 1997 |
| Redishall Caravan Park Limited | Hospitality | 2024 |