| OMNI FORT IT LTD | London | A rating |
| Omni Pump International Limited T/As Edincare | Hemel Hempstead | A rating |
| Omni Resource Management Solutions Limited | Altrincham | A rating |
| Omni Subsea Limited | Newmachar | A rating |
| OMNI SWEET CENTRE | BIRMINGHAM | A rating |
| Omni-id Limited | Farnham | A rating |
| Omnia Care Home Group Ltd | Birmingham | A rating |
| Omnia Housing Ltd | London | A rating |
| Omnia Learning Trust | Twickenham | A rating |
| OMNIA RESOURCING LTD TA Staffing Match | Hounslow | A rating |
| Omnia Smart technologies Ltd | Fleet | A rating |
| Omnia Strategy LLP | London | A rating |
| Omnia Support Ltd | Birmingham | A rating |
| OMNIA-ENTERPRISES LIMITED | Oxfordshire | A rating |
| OMNIAC PHARMCONSULT LIMITED | Hertfordshire | A rating |
| Omnibus Solutions Limited | Oldham | A rating |
| Omnicare Pharmacy Ltd | Edinburgh | A rating |
| Omnicare Services Limited | Barnsley | A rating |
| Omnicell Limited | Irlam | A rating |
| Omnicom Europe Limited | London | A rating |
| OmniCyber Security Limited | Birmingham | A rating |
| Omnide Ltd | London | A rating |
| Omniearth Limited | Edinburgh | A rating |
| Omnigen Biodata Limited | Cambridge | A rating |
| OMNIGUARD LTD | Renfrew | A rating |
| Omnipark Dental Centre | Kent | A rating |
| Omnipotent Bio Ltd | London | A rating |
| Omnipresent Group Limited | London | A rating |
| Omnisports Limited | Manchester | A rating |
| Omnissa (UK) Limited | London | A rating |
| OMNITECH BUSINESS LTD | Northampton | A rating |
| Omnium International (UK) Ltd | London | A rating |
| Omnivita Limited | Hemel Hempsted | A rating |
| Omniyati Partners Ltd | Richmond | A rating |
| Omobono Ltd | London | A rating |
| Omoda & Jaecoo UK Limited | London | A rating |
| Omor Ltd | Swansea | A rating |
| Omorovicza Cosmetics Ltd | London | A rating |
| OMOUK Ltd | London | A rating |
| OMRAJ CHILDCARE LTD T/A Monkey Puzzle Day Nursery Walton On Thames | Walton-On-Thames | A rating |
| OMRON ELECTRONICS LIMITED | MILTON KEYNES | A rating |
| OMS (LONDON) LIMITED | Romford | A rating |
| OMS SIVAS S CREST OF THE WAVE | Heanor | A rating |
| Omsai Consulting Ltd | Maidenhead | A rating |
| Omsaisubs Limited | Kings Lynn | A rating |
| OMSHIVAY LIMITED | Bristol | A rating |
| Omshree Ganesh Ltd | Poole | A rating |
| OMSR Services Ltd | Cardiff | A rating |
| Omusubi Ltd | London | A rating |
| OMV Petrom UK Branch Office | London | A rating |
| OMV Supply & Trading Limited | London | A rating |
| Omya UK Limited | North Ferriby | A rating |
| On a Roll Indo Mexican Limited T/A On a Roll | Bristol | A rating |
| On A Roll Sandwich Company Ltd. | Middlesbrough | A rating |
| On Air Dining Ltd | FLEET | A rating |
| ON ASSOCIATES LIMITED | Birmingham | A rating |
| ON BEHALF SOLUTIONS LIMITED | CARDIFF | A rating |
| On Call Property Services Ltd | Croydon | A rating |
| On Device Solutions Ltd | Shirley | A rating |
| On Direct Business Services Limited | Reading | A rating |
| ON ELECTRICAL & FIRE ALARM LTD | Cheshunt | A rating |
| On Field Investment Research LLP | London | A rating |
| On Fleek Tech Ltd | London | A rating |
| ON HEIGHT CONVENIENCE LTD | Salford | A rating |
| ON HOLD COMMUNICATIONS LIMITED | London | A rating |
| On Line Design & Engineering Limited | IMMINGHAM | A rating |
| ON MOVE LTD | Slough | A rating |
| ON POINT STUDY LIMITED | London | A rating |
| On Purpose Careers Limited | London | A rating |
| On Running UK Ltd | London | A rating |
| ON Semiconductor Limited | Bracknell, Berkshire | A rating |
| On Services UK Ltd | London | A rating |
| On Sight Limited | London | A rating |
| On Site Security | Bristol | A rating |
| on systems ltd | Letchworth | A rating |
| On the Beach | Manchester | A rating |
| ON THE DOT COURIERS LTD | Littleborough | A rating |
| On the Morrow Limited | Stratford, London | A rating |
| ON THE MUNCHIES LTD | REDDITCH | A rating |
| On The Point marketing Limited T/A Point Marketing | London | A rating |
| On time care | Basingstoke | A rating |
| ON TIME WATCHES LTD T/A WILLESDEN JEWELLERS | LONDON | A rating |
| On Track Education Services | Bedford | A rating |
| ON TRAVELS LIMITED | Bury | A rating |
| On Your Bike Limited | East Grinstead | A rating |
| ONA CO., LTD | London | A rating |
| ONAISE MANAGEMENT LTD | Fearnhead, Warrington, | A rating |
| Onatti Productions Ltd | Warwick | A rating |
| Onbe Ltd. | London | A rating |
| ONBOARD CORRUGATED LTD | WOLVERHAMPTON | A rating |
| Onboard Global Solutions Limited | Aberdeen | A rating |
| OnboardIQ UK Limited (t/a Fountain) | London | A rating |
| OnBrand Group Ltd | St Albans | A rating |
| Oncacare (UK) Limited | London | A rating |
| ONCALL CARE SERVICE LTD | GLASGOW | A rating |
| Oncall Retail Ltd | Renfrew | A rating |
| Once Education Group Ltd | Hayes | A rating |
| Once For All | Basingstoke | A rating |
| Once Upon A Time Content Limited | London | A rating |
| Once Upon A Time Marketing Limited | London | A rating |
| OnCloud Consulting (Scotland) Ltd | Edinburgh | A rating |
| ONCOSEM UK LIMITED | Braintree | A rating |
| OncoSil Medical (UK) Limited | London | A rating |
| Oncu Global Limited | Coventry | A rating |
| OnDemand Concierge LTD | London | A rating |
| Ondine Restaurants Ltd | Edinburgh | A rating |
| Ondo Insurtech Plc | London | A rating |
| Ondra UK Limited | London | A rating |
| ONE & ONLY CAFE LTD | Hounslow | A rating |
| ONE 10 GRAPHICS LTD | Tipton | A rating |
| One 2 One Autos Ltd | Windsor | A rating |
| ONE 2 ONE SUPPORT SERVICES NOTTINGHAM LTD | NOTTINGHAM | A rating |
| ONE Academy Trust | Derbyshire | A rating |
| One Accord Surveyors Ltd | London | A rating |
| ONE Advisory Limited | London | A rating |
| One Agency Media Ltd | Manchester | A rating |
| One Air Limited | Hampton Wick | A rating |
| One Aldwych Hotel | London | A rating |
| One Another Ministries | Cannock | A rating |
| One Beyond | Farnborough | A rating |
| ONE BIG BITE WALSALL LIMITED T/A ONE BIG BITE | West Midlands | A rating |
| One Body LDN ltd | Woodford Green | A rating |
| One Bright Dot | Brighouse | A rating |
| One Call 24 Healthcare Limited | London | A rating |
| One Call Care Solutions Ltd | Leyburn | A rating |
| One Call Insurance Services Limited | Doncaster | A rating |
| ONE CAR PLANET LTD | Ilford | A rating |
| ONE CARDS & STATIONERY LTD | Ilford | A rating |
| ONE CHECHI LTD | London | A rating |
| One Church Brighton | Brighton | A rating |
| One Church Leicester | Leicester | A rating |
| One Circle Events Ltd | London | A rating |
| One City Global Ltd | London | A rating |
| One Click Crazy Deals Limited | Leicester | A rating |
| One Clinic Ltd T/A MCR Implant Centre | Manchester | A rating |
| One Community Hampshire And Dorset ltd | Southampton | A rating |
| One Community Link | Stockton on tees | A rating |
| One Components Ltd | Bishop's Stortford | A rating |
| One Contract Services Ltd | Thornton Heath | A rating |
| ONE Creative environments (ONE) | Worcester | A rating |
| One Day At A Time Home Care Ltd | Woodley | A rating |
| ONE DEE LIMITED | London | A rating |
| One Dental | Londonderry | A rating |
| One Dot World Ltd | Surrey | A rating |
| One Environments Ltd | Newcastle upon Tyne | A rating |
| One Fiinix Live Limited | London | A rating |
| ONE FLEET REALTY LTD | LONDON | A rating |
| ONE FOOD (LONDON) LTD | London | A rating |
| ONE FOR ALL SUPERMARKET LTD | Crewe | A rating |
| ONE GLOBAL FOOD LTD | London | A rating |
| One Good Thing Ltd. | Hitchin | A rating |
| One Group Projects Limited T/A Bloom Cafe | London | A rating |
| One Group Solutions London Limited | London | A rating |
| ONE Healthcare Limited | Wokingham | A rating |
| One Heart Clinic LLP | London | A rating |
| One Heritage Property Development Limited | Manchester | A rating |
| ONE HOLDING NORTH LIMITED TA BEDMASTER | Batley | A rating |
| One Home Church | Emsworth | A rating |
| ONE HOME MINIMART LTD | Manchester | A rating |
| ONE HOME STORE LTD | Wednesbury | A rating |
| One Hotel Limited | Swansea | A rating |
| One House Artists Limited | London | A rating |
| One Investment Management Group UK Ltd | London | A rating |
| One LDN 360 Limited | London | A rating |
| One Life Health Support Ltd t/a Caremark Surrey Heath & Rushmoor | Farnborough | A rating |
| One Little Independent Ltd T/A One Little Independent Records | London | A rating |
| One London City Limited | London | A rating |
| One Love Caribbean Restaurant Limited | Romford | A rating |
| One Love Kitchen | London | A rating |
| One Luxury Group Advisors LLP | London | A rating |
| One Managed Services Ltd | Leicester | A rating |
| ONE MIND LIMITED | Sheffield | A rating |
| One Minute Silence Ltd t/a Flume | Solihull | A rating |
| One Mission Society | Belfast | A rating |
| One Money Mail Ltd | London | A rating |
| One More Bowl Ltd | London | A rating |
| One Move Property Group Ltd | London | A rating |
| One Nation | Batley | A rating |
| One Nine Seven Early Years Nursery | Kingston-Upon-Thames | A rating |
| One Ocean Planet | london | A rating |
| One of Us Ltd | London | A rating |
| One of Us Ltd. | London | A rating |
| One Peak Partners LLP | London | A rating |
| One Plus Restaurant Limited | Manchester | A rating |
| One Point Consulting Ltd | London | A rating |
| One Polo Limited | Maidstone | A rating |
| One Rebel Ltd | London | A rating |
| One Represents Ltd | LONDON | A rating |
| One Retail Group Limited | London | A rating |
| One Risk Africa Ltd | London | A rating |
| One School Group Limited | London | A rating |
| One Scientific Ltd | Bristol | A rating |
| One Search Ltd | Mayfair | A rating |
| One Sightsolutions LTD | Eastleigh | A rating |
| One Sixty Fundraising Limited | Leeds | A rating |
| ONE SOURCE ACCOUNTANCY SERVICES LTD | Glasgow | A rating |
| One Source Virtual (UK) Limited | Derry | A rating |
| ONE SQUARE BUSINESS LTD T/A Narvana | Stafford | A rating |
| ONE SQUARE ONE LIMITED | Bolton | A rating |
| ONE STEP AHEAD FOOD SAFETY LTD | Swansea | A rating |