| Noseum Editions LtdOxted, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2024 |
| Nostimo Delicatessen LtdColchester, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2015 |
| Novus Trading LtdBristol, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2007 |
| Nrs Jewellers LimitedRuislip, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2015 |
| Numatic International LtdCamberley, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 1963 |
| Nuneham Estate LimitedGoring, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2016 |
| Oak Tree Loch Lomond LtdGlasgow, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2009 |
| Ocean Pantry LimitedLeicester, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2015 |
| Ocs Group International LimitedLondon, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 1994 |
| Odd Firm of Sin LimitedNorthiam, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 1997 |
| Offshore Water Management LtdWesthill, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2008 |
| Oldbourne & Oldbourne Hospitality LimitedLondon, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2015 |
| Omb Tax LimitedTunbridge Wells, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2003 |
| On Cloud Wine Za LtdThames Ditton, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2021 |
| Oppermann London LtdLondon, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2012 |
| Options Group LtdEdgware, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 1999 |
| Orbit Brewing LimitedLondon, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2013 |
| Orchard-Lisle WinesSaxmundham, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2018 |
| Organic Grape Spirit LtdAshford, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2019 |
| Orlando's Fine Foods LtdAylesbury, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2020 |
| Outernet Venue LimitedLondon, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2021 |
| Overseas Courier Service LimitedColnbrook, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 1972 |
| Oxford Export Services LtdWatlington, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 1989 |
| Oxford Immunotec Global LimitedAbingdon, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2013 |
| Oxygen Health Communications LtdLondon, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2006 |
| P J Shipping LimitedDover, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 1999 |
| Pai Partners LimitedLondon, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2000 |
| Pakwin LtdBirmingham, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2019 |
| Pamarco Europe LtdHuddersfield, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 1992 |
| Paragon Brands LimitedManchester, United Kingdom · UKparagonbrands.co.uk · checked 28 Oct 2026 | UK | 1 | – | – | – | – | 2017 |
| Parallel Contemporary Art LtdEpsom, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2010 |
| Park Side London LtdUnited Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2022 |
| Partner In Wine LtdLondon, United Kingdom · UKpartnerinwine.co.uk · checked 28 Oct 2026 | UK | 1 | – | – | – | – | 2020 |
| Party Ingredients Catering Services LimitedReading, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2006 |
| Pascall Wines LimitedLondon, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2022 |
| Passion Wines LtdTadley, United Kingdom · UKlapassionduvin.com · checked 28 Oct 2026 | UK | 1 | – | – | –Premium (producers) | 34% | 2024 |
| Pastabymamma LimitedLondon, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2013 |
| Patek Philippe Salon LimitedBeaconsfield, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2005 |
| Pendennis ShipyardCornwall, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 1988 |
| Pendulum Spirits LimitedLivingston, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2020 |
| Pengems LimitedLondon, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 1979 |
| Perenco UK LimitedLondon, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2003 |
| Peruvian Enterprises LtdLeeds, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2004 |
| Petroassist UK LtdLoanhead, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2014 |
| Pfih LtdUnited Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2005 |
| Pfm Packaging Machinery LtdStanningley, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 1987 |
| Pgim Financial LtdEdinburgh, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 1999 |
| Phan Box Sunshine LimitedLondon, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2011 |
| Phi Partners International LimitedLondon, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 2020 |
| Phoenix Group LimitedSwaffham, United Kingdom · UKchecked 28 Oct 2026 | UK | 1 | – | – | – | – | 1996 |