| Plotly Europe Ltd | London | A rating |
| Plowman Craven Limited | Harpenden | A rating |
| Plural UK Management Limited | London | A rating |
| Plus 39 Limited | Rochester | A rating |
| Plus Kitchen UK | London | A rating |
| PM Alliance Inc | Belfast | A rating |
| PM Project Services Limited | Solihull | A rating |
| PMB Battery Technologies UK Ltd | Blaenau | A rating |
| PMI Europe Limited | London | A rating |
| PNB (UK) LIMITED | London | A rating |
| PNC Financial Services UK Ltd | Haywards Heath | A rating |
| PNS (UK) Ltd | Normanton | A rating |
| Poclain Hydraulics Limited | Oundle | A rating |
| Poeticgem Limited | Watford | A rating |
| Point72 UK Limited | London | A rating |
| Points International | Kew | A rating |
| Pokemon Company International, Inc | London | A rating |
| Polar Capital Partners Limited | London | A rating |
| PolarDC Services Ltd | London | A rating |
| Pole Star Space Applications Ltd. | London | A rating |
| Polen Capital UK LLP | London | A rating |
| Polestar Automotive UK Limited | Bicester | A rating |
| Poliform UK Limited | Weybridge | A rating |
| POLTRONA FRAU ( UK) LIMITED | LONDON | A rating |
| POLYMER LOGISTICS (SCOTLAND) LTD | GRANGEMOUTH | A rating |
| Polyn Technology Limited | Fitzrovia | A rating |
| Polytec Car Styling UK Ltd | Bromyard | A rating |
| Pomona Europe Advisers Limited | London | A rating |
| Pontegadea UK Ltd | London | A rating |
| Populous Ltd | London | A rating |
| PORR UK Ltd | Uxbridge | A rating |
| Porsche Cars GB Ltd. | Reading | A rating |
| Porsche Financial Services Great Britain Ltd | Reading | A rating |
| Porsche Retail Group Limited | Reading | A rating |
| Port Saffron Limited | London | A rating |
| Portakabin Limited | Huntington | A rating |
| PORTAKABIN LIMITED | YORK | A rating |
| Portas Consulting Limited | London | A rating |
| Portfolio BI Ltd | London | A rating |
| POSCO INTERNATIONAL CORPORATION LONDON BRANCH | London | A rating |
| POSCO International Deutschland GmbH | London | A rating |
| Posh Virtual Receptionists UK Limited | Reading | A rating |
| Position Green UK Ltd | London | A rating |
| POSTCODE LOTTERY LIMITED | EDINBURGH | A rating |
| Postdot Technologies UK Ltd | London | A rating |
| Potenza Technology Ltd | Basildon | A rating |
| Powell (UK) Ltd | Bradford | A rating |
| Powell UK Ltd | Bradford | A rating |
| Power and Energy International | Newbury | A rating |
| Power Electronics Corp. UK Limited | London | A rating |
| Power Integrations UK Limited | Cambridge | A rating |
| Power Systems Consultants UK Limited | London | A rating |
| Power2Motivate UK Limited | London | A rating |
| Powerteam Electrical Services (UK) Ltd | Belfast | A rating |
| Poyry plc | Oxford | A rating |
| PPA ENERGO S.R.O. | Hitchin | A rating |
| PPD Global Ltd | Cambridge | A rating |
| PPG Industries (UK) Ltd | Stowmarket | A rating |
| PPM International (London), Ltd | London | A rating |
| PPRO Financial Ltd | London | A rating |
| PQE GROUP LTD | London | A rating |
| PRA | Reading | A rating |
| PRA Group (UK) Ltd | Kilmarnock | A rating |
| Practical Action | Rugby | A rating |
| Prada Retail UK Ltd | London | A rating |
| PRATHAM SOFTWARE LTD | HARROGATE | A rating |
| Pratt & Whitney (Canada) UK Ltd | Leighton Buzzard | A rating |
| Pratt & Whitney Military United Kingdom Limited | Luton | A rating |
| Praytell UK Limited | London | A rating |
| Precisely Software Limited | Reading | A rating |
| Precision Polymer Engineering Ltd | Blackburn | A rating |
| Prelude Capital (UK) Limited | London | A rating |
| PREMATCH Sports Ltd. | London | A rating |
| Premdor Crosby Limited | Barnsley | A rating |
| Premier Corex Ltd | Aberdeen | A rating |
| Premier Farnell Ltd | Leeds | A rating |
| Premier Paper Group Ltd | Minworth | A rating |
| Prepaid Financial Services Limited | London | A rating |
| Prepay Technologies trading as PPS | Swindon | A rating |
| Preply UK Services Limited | London | A rating |
| Preqin Ltd | London | A rating |
| Presserv Limited | Aberdeen | A rating |
| Prestige International U.K. Limited | Croydon | A rating |
| Pret a Manger (Europe) Limited | London | A rating |
| Pretium UK Partners Limited | London | A rating |
| Prevalent AI Limited | London | A rating |
| Prezzee UK Limited | London | A rating |
| Prezzemolo & Vitale Uk ltd | London | A rating |
| PRGX UK LTD | LUTON | A rating |
| Priceline.com Europe Limited | London | A rating |
| PRICETRACE UK LTD | Manchester | A rating |
| PricewaterhouseCoopers LLP | London | A rating |
| Pride Mobility Products Ltd | Bicester | A rating |
| Prima Ekuiti (UK) Ltd | London | A rating |
| Prima Subsidary Ltd | London | A rating |
| PRIME FOCUS INTERNATIONAL SERVICES UK LTD | LONDON | A rating |
| Prime Global Medical Communications Limited | Cheshire | A rating |
| Prime Global Ventures Ltd | London | A rating |
| PRIMEKSS UK LTD | Melton Mowbray | A rating |
| PrimeRevenue UK Limited | London | A rating |
| Primetals Technologies Limited | Sheffield | A rating |
| Primex Plastics Limited | Newton Aycliffe | A rating |
| Princes Group plc | Liverpool | A rating |
| Princes Limited | Liverpool | A rating |
| Princeton University Press | Oxford | A rating |
| Principal Global Investors (Europe) Limited | London | A rating |
| Prinova Europe Limited | London | A rating |
| PRISM Energy International London Office | London | A rating |
| Prism Financial Products LLP | London | A rating |
| PRO INSURANCE SOLUTIONS LIMITED | GLOUCESTER | A rating |
| ProAmpac Elsham plc | Brigg | A rating |
| ProAmpac Grimsby Limited | Grimsby | A rating |
| ProAmpac Lincoln Limited | Lincolnshire | A rating |
| ProArch IT Solutions Limited | London | A rating |
| PROCEPT BioRobotics UK Ltd | Derby | A rating |
| Processia Solutions Ltd | Coventry | A rating |
| Procon Wind Energy Limited | Warwick | A rating |
| Procore UK Limited | London | A rating |
| Procter & Gamble Limited | Surrey | A rating |
| Procurement Leaders Limited | London | A rating |
| ProcureTech Limited | London | A rating |
| Procurious Limited | GUILDFORD | A rating |
| PRODAPT (UK) LIMITED | READING | A rating |
| Prodege UK, Ltd | London | A rating |
| Prodigious UK Limited | London | A rating |
| Prodigy Finance Limited | London | A rating |
| Productboard UK Ltd | Reading | A rating |
| Production Resource Group UK Ltd | Longbridge | A rating |
| Profisee Software UK Limited | London | A rating |
| Program Management Services UK Limited | London | A rating |
| Program Planning Professionals Limited (Pcubed) | London | A rating |
| Progress Rail Services UK Limited | Nottingham | A rating |
| Progroup Board Ltd | Ellesmere Port | A rating |
| Project A Ventures Management | London | A rating |
| Project People Limited | Bristol | A rating |
| Projective Group UK Limited | London | A rating |
| Prolifics Inc | London | A rating |
| Prologis UK Limited | Solihull | A rating |
| Prometeon Tyre Group UK Ltd | Burton on Trent | A rating |
| Promethean Limited | Clitheroe | A rating |
| Prometheus Enterprises U.K. Limited | Leeds | A rating |
| Promise Corporation Limited | London | A rating |
| ProMX UK Limited | Reading | A rating |
| Proof London Limited | London | A rating |
| Proofpoint Limited | Reading | A rating |
| Propav Infrastructure Ltd | London | A rating |
| ProPharma Group MIS Limited | Richmond | A rating |
| Prophet Brand Strategy Limited | London | A rating |
| Prophix UK Limited | Reading | A rating |
| PROPTECH AERO LTD | Lee-On-The-Solent | A rating |
| ProQuest Information and Learning Limited | Cambridge | A rating |
| PROS Europe Limited | London | A rating |
| Prosafe Offshore Ltd | Westhill | A rating |
| Prosegur Security UK Ltd | Braintree | A rating |
| Prosek UK Limited | LONDON | A rating |
| Proserv UK Ltd | Westhill | A rating |
| Proskauer Rose (London) LLP | London | A rating |
| Proskauer Rose (UK) LLP | London | A rating |
| Prosper Robotics Ltd | London | A rating |
| Protector Insurance | Manchester | A rating |
| Protegrity Europe Limited | London | A rating |
| Proteo Ltd | Norwich | A rating |
| Protiviti Limited | London | A rating |
| Proton Technologies Ltd | London | A rating |
| Prove Identity Ltd | London | A rating |
| Prudential PLC | London | A rating |
| Prysmian Cables & Systems Limited | Eastleigh | A rating |
| Prysmian Powerlink Services Limited | Middlesbrough | A rating |
| PS Hummingbird | Teddington | A rating |
| PSC Biotech Ltd | Newry | A rating |
| PSC Service Company Limited | London | A rating |
| pSemi Corporation | Theale | A rating |
| PSI CRO UK Ltd | Kidlington | A rating |
| PsiQuantum Ltd | Burnham | A rating |
| PSL Capital Limited | London | A rating |
| PSP Investments Holding Europe Ltd | London | A rating |
| PT Bank Negara Indonesia (Persero) bk | London | A rating |
| PTT International Trading London Ltd | London | A rating |
| PTV (UK) Limited | Birmingham | A rating |
| PUBLIC Group International Limited | London | A rating |
| Public Interest Incorporated Association The Japan Association of Marine Safety London Office | London | A rating |
| Publicis Healthcare Communications Group Limited | London | A rating |
| Publicis Limited | London | A rating |
| PubMatic Ltd | London | A rating |
| PubNub UK Limited | London | A rating |
| Puig UK Limited | London | A rating |
| Pulse Films Ltd | London | A rating |
| PUMA UNITED KINGDOM LIMITED | Castleford | A rating |
| PUNJAB NATIONAL BANK (INTERNATIONAL) LIMITED | LONDON | A rating |
| Puppet Labs Limited | Bracknell | A rating |
| Pure Data Centres | London | A rating |
| Pure Recruitment Group | London | A rating |
| Pure Storage UK Limited | Staines upon Thames | A rating |
| Purem Cowley Ltd | Hampshire | A rating |
| Purico Limited | Nottingham | A rating |
| Purolite Ltd | Llantrisant | A rating |
| Purple Surgical UK Ltd | Shenley | A rating |
| PURPOSE EUROPE LIMITED | LONDON | A rating |
| PUSULA CUSTOMER EXPERIENCE UK LTD | London | A rating |
| Putnam Associates Limited | London | A rating |