| P & D Engineering | Coventry |
| P & O Ferries | Dover |
| Paddy Power | London |
|
Pain Relief Foundation | Liverpool |
| Panasonic UK Ltd | Bracknell |
| Pankhurst Contracting Ltd | Aylesford |
| Parallel Media Group Plc | London |
| Paramount Comedy | London |
| Parfetts | Stockport |
| Parfums Christian Dior (UK) Ltd | London |
| Parfums Givenchy Ltd | London |
| Park Caledonia | London |
| Parker Harris & Company | Esher |
| Parkhouse Personnel Ltd | Luton |
| Parks Motor Group | Hamilton |
| Passion | London |
| Pearl & Dean Cinemas Ltd | London |
| Pearson | London |
| Peel Holdings Plc | Manchester |
| Pegasus Retirement Homes | Cheltenham |
| Pegler Ltd | Doncaster |
| Penningtons Solicitors LLP | London |
| Perfect Motion Sports Marketing | Nottingham |
| Performance | London |
| Performance Worldwide | London |
| PerforMind | Cobham |
| The Perfume Shop | High Wycombe |
| Periodical Publishers Association (PPA) | London |
| Pernod Ricard UK | Hounslow |
| Perrys of Barnsley | Barnsley |
| Pertemps Recruitment Partnership Limited | Meriden |
| Peter Whates & Associates Ltd | Buckingham |
| Peter Wilkinson Associates | London |
| Peugeot Motor Company PLC | Coventry |
|
PGA European Tour & The Ryder Cup | Virginia Water |
| Philips Electronics UK Ltd | Guildford |
| Phillips de Pury & Company | London |
| Phipps Public Relations Ltd | London |
|
The Phoenix Consultancy | Bournemouth |
| Phoenix Whirlpools Ltd | Leeds |
| PIMS-SCA | London |
| Pindar plc | Scarborough |
| Pinnacle | London |
| Pinsent Masons | London |
| Pioneer (GB) Ltd | Slough |
| Pipex Internet Ltd | Aylesbury |
| Pirelli Tyres Ltd | Burton-on-Trent |
| Pitch PR | London |
| Pittards PLC | Yeovil |
| Pizza Express plc | Uxbridge |
| Pizza Hut (UK) Ltd | Borehamwood |
| PJ | Reading |
| Platinum One | Edinburgh |
| Playmaker Communications Ltd | South Leigh |
| Playmaker Sports Marketing | London |
| Playtex Ltd | Woking |
| PlusNet | Sheffield |
| Podium | Belfast |
| Polygon Marketing Ltd | Cheltenham |
| Pontin's Ltd | Chorley |
| The Pony Club | Kenilworth |
| Port of Felixstowe | Felixstowe |
| Portman Building Society | Bournemouth |
| Powerplay Partnerships | Upton-on-Severn |
| Premier Foods Ltd | St Albans |
| Premier Rugby | Twickenham |
| Prestige Mobility | Bangor |
|
Price Nicholson | Leatherhead |
| Pricebusters | Blackpool |
| PricewaterhouseCoopers | London |
| Primary Sponsorship Ltd | Oxford |
| Prime Time Recruitment Ltd | Northampton |
| Principality Building Society | Cardiff |
| Pringle of Scotland Ltd | London |
| The Priory Partnership Ltd | Brighton |
| PRISM | London |
| Privilege Insurance | Croydon |
| Procter & Gamble UK | Newcastle upon Tyne |
| Producers Alliance for Cinema & Television Ltd (PACT) | London |
| The Professional Darts Corporation Ltd | Brentwood |
| Professional Footballers' Association (PFA) | Manchester |
| Professional Footballers' Association (PFA) | Manchester |
| The Professional Golfers' Association (PGA) | Sutton Coldfield |
| Professional Sports Ventures | Chobham |
| ProHelp | London |
| Property Finder.com | London |
| Proscot Public Relations Consultants | Edinburgh |
| Proton Cars (UK) Ltd | Norwich |
| Provident Financial plc | Bradford |
| Psion Plc | London |
| Ptarmigan Consultants Ltd | Leeds |
| The Publishers Association (PA) | London |
| Pukka Pies Ltd | Leicester |
| Pullum Sports | Luton |
| Puma UK | Leatherhead |
| Purely Scottish Mineral Water Distribution Ltd | Cockburnspath |
| Purple Tangerine | Ashford |
| PZ Cussons UK | Stockport |