| UK Company Name | Partial Address |
| O'Prey Developments Limited | KIRCUBBIN, NEWTOWNARDS |
| O-Perspective Ltd | Lincoln |
| O. P. L. Limited | HARROW, MIDDLESEX |
| O.P. Catering Limited | CROYDON, SURREY |
| O.P. Chocolate Limited | DOWLAIS, MERTHYR TYDFIL |
| O.P.D Limited | Torquay |
| Opal Contracts (U.K.) Limited | Solihull, West Midlands |
| Opal Food Processing Systems Limited | ST IVES, CAMBRIDGESHIRE |
| Opaltec International Limited | AVONMOUTH, BRISTOL |
| Opatra Limited | Windsor Avenue, London |
| Opcare Limited | Abingdon, Oxfordshire |
| Opd Group Limited | BROXBOURNE, HERTFORDSHIRE |
| Opd Laboratories Limited | 54-60 Baker Street, London |
| Opecprime Development Limited | Oakleigh Road South, London |
| Opecprime Limited | Oakleigh Road South, London |
| Opecprime Properties Limited | Oakleigh Road South, London |
| Open Book Consulting Ltd | LONDON |
| Open College Network Northern Ireland | UNIT 5, BELFAST |
| Open Credo Limited | 15 FINSBURY CIRCUS, LONDON |
| Open Design Systems Ltd | Newark, Notts |
| Open Destinations Limited | Unit 12 7 Wenlock Road, London |
| Open Door Communications Ltd | HASTINGS |
| Open Door Consultants Limited | SOUTHEND ON SEA, ESSEX |
| Open Fibre Networks (Wholesale) Limited | WOOLPIT, BURY ST. EDMUNDS |
| Open G I Limited | Warndon, Worcester |
| Open Gi London Limited | Worcester, Worcestershire |
| Open Golf And Leisure Limited | Bolton, Lancashire |
| Open Health Communications Llp | 10th Floor, London |
| Open House Festival Limited | 16 Quay Street, Bangor |
| Open House Trust Limited | ENNISKILLEN, CO. FERMANAGH |
| Open Insurance Services Uk Limited | 91 Wimpole Street, London |
| Open International Limited | Warndon, Worcester |
| Open Retail Solutions Limited | Beeston, Nottingham |
| Open Seas (Uk) Limited | EAST HANNEY, OXFORDSHIRE |
| Open Text Uk Limited | Reading, Berkshire |
| Openbet Limited | 566 CHISWICK HIGH ROAD, LONDON |
| Opencontact Limited | SURREY STREET, NORWICH |
| Opencorporates Ltd | CORNWALL AVENUE, LONDON |
| Opendoor Print Limited | BASINGSTOKE, HAMPSHIRE |
| Openfolde Limited | Belfast |
| Openlink Software (Uk) Limited | PURLEY WAY, CROYDON |
| Openmarket Limited | 35-38 NEW BRIDGE STREET, LONDON |
| Openside 777 Ltd | TARPORLEY, CHESHIRE |
| Opensite Contracts Limited | SOUTHEND ON SEA, ESSEX |
| Openslot Property Management Limited | SEVENOAKS |
| Opentable International Limited | 14-18 FINSBURY SQUARE, LONDON |
| Opentable Uk Holding Limited | 14-18 FINSBURY SQUARE, LONDON |
| Openwork Limited | Lydiard Fields, Swindon |
| Openwork Partnership Llp | Lydiard Fields, Swindon |
| Operation Europe Limited | 45 BEAVOR LANE, LONDON |
| Operational Agility Ltd. | LONDON, LONDON |
| Operational Excellence (Opex) Group Ltd | 6TH FLOOR, EDINBURGH |
| Operator Training Services Limited | ASHFORD, KENT |
| Operis Construction Ltd | 55 LUDGATE HILL, LONDON |
| Opex Corporation | NEW JERSEY 08057, USA |
| Opg Ltd. | LESMAHAGOW, LANARKSHIRE |
| Opico Limited | BOURNE, LINCOLNSHIRE |
| Opl Hollowcore Limited | WEATING, NORFOLK |
| Oplan Office Furniture Limited | ST NEOTS, CAMBRIDGESHIRE |
| Oplo Group Ltd | Sir Frank Whittle Way, Blackpool |
| Opm (Labels & Packaging) Group Limited | 55 Gelderd Road, Leeds |
| Opm Group Limited | 55 Gelderd Road, Leeds |
| Opm International Ltd | BURY, LANCASHIRE |
| Opm Limited | LITTLEHAMPTON, SUSSEX |
| Opodo Limited | LONDON |
| Oponeo.Co.Uk Ltd | EALING BROADWAY, LONDON |
| Opos Limited | Dumbarton |
| Oppenheimer Europe Ltd. | 125 WOOD STREET, LONDON |
| Opportune Limited | BOLTON, GREATER MANCHESTER |
| Opportunitas Limited | 36 - 38 WIGMORE STREET, LONDON |
| Oppulant Ltd | GLOUCESTER, GLOUCESTERSHIRE |
| Oprema Limited | St Mellons, Cardiff |
| Opro International Limited | London |
| Opro Limited | London |
| Opso Limited | BOSTON ROAD, LONDON |
| Opt Tech (Uk) Limited | CROYDON |
| Optal Financial Limited | London |
| Optare Plc | ROTHERHAM, SOUTH YORKSHIRE |
| Optelec Limited | Quarry Hill Industrial Estate, Ilkeston |
| Opteven Holdings Uk Ltd | THAME, OXFORDSHIRE |
| Opti-Fuel Ltd | ST. PAULS ROAD, SHIPLEY |
| Optical Express (Holdings) Limited | GLASGOW |
| Optical Express (Westfield) Limited | GLASGOW |
| Optical Express Limited | GLASGOW |
| Optical Sciences Limited | Clayfield Close, Northampton |
| Optical Services & Sales Limited | NEWPORT, GWENT |
| Optical Test And Calibration Limited | BRADFORD, WEST YORKSHIRE |
| Opticare Solutions Limited | Meridian Business Park, Leicester |
| Opticore It Ltd | 18 BEVIS MARKS, LONDON |
| Optigene Limited | HORSHAM, WEST SUSSEX |
| Optilase (Uk) Limited | BELFAST |
| Optilight Limited | HUNTINGDON, CAMBRIDGESHIRE |
| Optima Care Limited | 1 Waldegrave Road, Teddington |
| Optima Health (Birmingham) Limited | 2 Hayland Street, Sheffield |
| Optimal Technologies Limited | LETCHWORTH GARDEN CITY, HERTFORDSHIRE |
| Optimas Oe Solutions Ltd | Waterwells Drive Quedgeley, Gloucester |
| Optimax (Uk) Limited | ALVECHURCH, WORCESTERSHIRE |
| Optimise Systems Ltd | COLLINGHAM, NEWARK |
| Optimity Limited | LONDON |
| Optimo Research Ltd | LONDON |
| Optimold Limited | GOLBORNE, WARRINGTON |
| Optimor Limited | London |
| Optimum Heating Limited | Barnstaple |
| Optimum Marketing Limited | Edgbaston, Birmingham |
| Optimum Nutrition Emea Limited | ABERDEEN, SCOTLAND |
| Optimum.Aero Limited | Ford, Arundel |
| Optimum4 Limited | 100 WELLINGTON STREET, LEEDS |
| Optimus Cards Uk Limited | 27/28 EASTCASTLE STREET, LONDON |
| Optimus Flowers Limited | SOUTHAMPTON, HAMPSHIRE |
| Optimus Medical Limited | RETFORD, NOTTINGHAMSHIRE |
| Optio Systems Limited | DERBY ROAD, NOTTINGHAM |
| Options Management Limited | Newcastle, Staffordshire |
| Options Resourcing Sussex Llp | 2-6 Shirley Road, Southampton |
| Options Technology Limited | ST. JAMES'S, LONDON |
| Optisoft Ltd | YORK, NORTH YORKSHIRE |
| Optiva Securities Limited | London |
| Optivia Limited | MOLD, FLINTSHIRE |
| Optivite Limited | WORKSOP, NOTTINGHAMSHIRE |
| Optos Public Limited Company | DUNFERMLINE, FIFE |
| Optum Global Ltd | BALBY, DONCASTER |
| Optum Health Solutions (Uk) Limited | Paddington, London |
| Optum Solutions Uk Holdings Limited | MARLOW, BUCKINGHAMSHIRE |
| Optune Homes Limited | BLACKPOOL, LANCASHIRE |
| Opulence Executive Travel Limited | Bradford, West Yorkshire |
| Opulent Trading Limited | Mayfair, London |
| Opus Contracts Limited | SPONDON, DERBY |
| Opus Energy Group Limited | Selby, North Yorkshire |
| Opus Energy Limited | Selby, North Yorkshire |
| Opus Group Holdings Limited | CHIPPENHAM, WILTSHIRE |
| Opus Healthcare Ltd. | CHIPPENHAM, WILTSHIRE |
| Opus Limited | Enniskillen, Fermanagh |
| Opus Music Community Interest Company | Blackwell, Alfreton |
| Opus Retail Solutions Limited | BELFAST, CO. ANTRIM |
| Opus Technologies Limited | Hankey Place, London |
| Opus Wealth Management Ltd | SOUTHPORT |
| Opus-Uk Limited | CHARLOTTE STREET, MANCHESTER |