| Securi Serve Ltd | Manchester | A rating |
| SecuriGroup Limited | Glasgow | A rating |
| Securis Investments Limited | London | A rating |
| Securitas | Bucks | A rating |
| Securitas Technology Limited | Milton Keynes | A rating |
| Securiti Sciences Limited | Altrincham | A rating |
| Security 212 Limited | Coventry | A rating |
| SECURITY 247 LTD | Cradley Heath | A rating |
| Security Alliance Limited | Exeter | A rating |
| Security and Homeworks LIMITED | Birmingham | A rating |
| Security Earpiece Ltd | Ilford | A rating |
| Security Exchange Ltd | Reading | A rating |
| SECURITY GROUP SERVICES LTD | Peterborough,England, | A rating |
| SECURITY RISK SPECIALISTS LTD | Clerkenwell | A rating |
| SECURITY SERVICES & SYSTEMS LIMITED | Barking | A rating |
| Security Systems Design Ltd | Huntingdon | A rating |
| Security Window Shutters Limited | Lancaster | A rating |
| SecurityHQ Ltd | London | A rating |
| SECURIWISE LIMITED | Cambridge | A rating |
| Securonix UK Limited | London | A rating |
| Securteam Limited | London | A rating |
| SECURTECH LIMITED | Richmond | A rating |
| Securys Limited | London | A rating |
| SecuTix Limited | London | A rating |
| Sed Medicons Ltd | London | A rating |
| SED.Group Ltd. (Serenity Education Group Ltd.) | Eltham | A rating |
| Seda Pharma Development Services Ltd | Cheadle | A rating |
| Seda UK Limited | Blackwood | A rating |
| SEDAMYL UK LTD | Selby | A rating |
| Sedana Supermarket UK Ltd | Birmingham | A rating |
| Sedbergh Hotel Enterprises Limited (The Black Bull) | Sedbergh | A rating |
| Sedbergh School | Sedbergh | A rating |
| Sedem Ltd | Liverpool | A rating |
| Sedex Information Exchange Limited | London | A rating |
| SEDGEMOOR SERENITY SERVICES LTD | Stoke-On-Trent | A rating |
| Sedgwick International UK | LONDON | A rating |
| Sediqi & Sediqi Ltd T/A Sediqi & Sediqi Solicitors | Hounslow | A rating |
| Sedivcharan Limited | Watford | A rating |
| Sedna Lighting Ltd | CARDIFF | A rating |
| Sedna Systems Europe Limited | London | A rating |
| Sedpaac Ltd | Leicester | A rating |
| Sedulo Accountants Ltd | Manchester | A rating |
| SEE WORLD LTD | Wembley | A rating |
| See-Ability Ltd t/aThe Royal School For The Bllind | Leatherhead | A rating |
| See-Saw Films Ltd | London | A rating |
| Seeai LTD. | Leeds | A rating |
| Seebay Ltd | Manchester | A rating |
| SeeByte Ltd | Edinburgh | A rating |
| SeeChange Technologies Limited | Manchester | A rating |
| SEED ABUNDANCE T/A SA ACCOUNTANCY LTD | CHATHAM | A rating |
| Seed Architects Limited | MANCHESTER | A rating |
| Seed Healthcare Services Ltd | Manchester | A rating |
| SEED Madagascar | LONDON | A rating |
| Seed Mentors Entrepreneurs Academy Consortium Ltd | Lanark | A rating |
| Seedcamp Services Ltd | London | A rating |
| SEEDLEGALS LTD | LONDON | A rating |
| SEEDLEY MINI MARKET LTD | Greater London | A rating |
| Seedlings Day Nursery Limited | London | A rating |
| Seedrs Limited | London | A rating |
| Seeds Care Ltd | Broadstairs | A rating |
| Seeds Day Service LTD | MELTON MOWBRAY | A rating |
| Seeds Healthcare Ltd | Leeds | A rating |
| Seedtag Advertising | London | A rating |
| Seehra Transport Limited | Oldbury | A rating |
| Seeking Answer Ltd | Barnet | A rating |
| seele UK Ltd | London | A rating |
| Seema News | Durham | A rating |
| SEEMAS BEAUTY SALON LTD | Southampton | A rating |
| Seemed Healthcare Limited | Oldham | A rating |
| Seen Connects Limited | London | A rating |
| seen interiors ltd | Notting Hill | A rating |
| Seen Studios Limited | London | A rating |
| SEEN TRADING LTD | Mitcham | A rating |
| Seenit Digital Limited | London | A rating |
| SEEPAUL UK (Ltd)T/A tanner street pharmacy | Thetford | A rating |
| SEEQC UK LIMITED | London | A rating |
| Seer Green Baptist Church | SEER GREEN, BEACONSFIELD | A rating |
| Seeracha Restaurant | Eastbourne | A rating |
| Seerah Limited T/A Heavenly Desserts Canterbury | Canterbury | A rating |
| SEERAT DEOL LIMITED | London | A rating |
| SeerBI | Stockton On Tees | A rating |
| Seerbytes Limited | Bushey | A rating |
| SEESAI LIMITED | Chichester | A rating |
| Seesaw Media Ltd | 235 Regents Park Road | A rating |
| Seeta Patel Dance Ltd | Bristol | A rating |
| Seetec Business Technology Centre Limited | Hockley | A rating |
| SEETHA SOFTWARE SOLUTIONS LTD | 18 Brainton Avenue | A rating |
| Seetru Ltd | Bristol | A rating |
| SEEWOO CHINATOWN LIMITED | London | A rating |
| Sefardi Ltd t/a Bala Baya | London | A rating |
| Sefas Innovation Ltd | BRISTOL | A rating |
| SEFE Marketing & Trading Limited | London | A rating |
| SEFE Marketing & Trading Ltd | London | A rating |
| SEFF- South East Fermanagh Foundation | Lisnaskea | A rating |
| SEFGROVE LTD | LONDON | A rating |
| SEFI STEEL LTD | Manchester | A rating |
| SEFP LTD Trading as Kent Horse Producers | Kent | A rating |
| Sefton Metropolitan Borough Council | Liverpool | A rating |
| Sefton Place Advisors Limited | London | A rating |
| SEGA Europe Limited | London | A rating |
| Sega International Limited | West Bromwich | A rating |
| Segarajah Mayuran T/a Hamina Store | Gloucester | A rating |
| Segen Ltd | Farnborough | A rating |
| Segmentify UK Ltd | London | A rating |
| Segregated Payments Ltd | Hatfield | A rating |
| SEGS ENTERPRISE LTD | Sleaford | A rating |
| SEGULA TECHNOLOGIES LTD | Luton | A rating |
| Sehaj Construction Limited | Dagenham | A rating |
| Sehaj Food Ltd | Llanharan | A rating |
| Sehaj Real Estate Limited | Leicester | A rating |
| SEHGAL AND GRANDSONS PRIVATE LIMITED | Hounslow | A rating |
| SEHJAL SUPERMARKET LIMITED | GILLINGHAM | A rating |
| SEHV Services Ltd | St. Leonards-on-Sea | A rating |
| SEI Investments (Europe) Ltd | London | A rating |
| SEI Oxford Office Ltd | Oxford | A rating |
| SEIA GLOBAL LTD | Harrow | A rating |
| Seibu Prince Hotels Worldwide, Inc. | London | A rating |
| Seidor UK Ltd | Weybridge | A rating |
| SEIMAF UK Limited | Bristol | A rating |
| Seir Ltd | Birmingham | A rating |
| Seismic Image Processing Ltd | Guildford | A rating |
| Seismic Software UK Limited | London | A rating |
| Seivwright Brothers Limited | Banff | A rating |
| SEJ Distribution Ltd | Hayes | A rating |
| SEJ Pharmaceutical Ltd | Hayes | A rating |
| SEJ RESTAURANTS GROUP LTD | Coalville | A rating |
| SEJAX MARKETING LTD | London | A rating |
| SEKEL TECHNOLOGIES UK LTD | Milton Keynes | A rating |
| Sekhon Building Services Ltd | Uxbridge | A rating |
| SEKHON CONSTRUCTION LIMITED | Hayes | A rating |
| Sekhon Haulage Ltd | Derby | A rating |
| Sekisui Diagnostics (UK) Limited | Maidstone | A rating |
| Seko City Ltd | Milton Keynes | A rating |
| Sektor.AI (UK) Ltd | London | A rating |
| Sekyee Computer Ltd | London | A rating |
| Sela Global Entertainment Co Limited | London | A rating |
| Sela Medical UK LTD | London | A rating |
| Seladore Legal Ltd | London | A rating |
| SELAH HOME CARE | EDINBURGH | A rating |
| Selbey Anderson Limited | London | A rating |
| SELBI SUPER SHOP LIMITED | London | A rating |
| Selco Builders Warehouse | Birmingham | A rating |
| SELDEK2025 LTD | Haywards Heath | A rating |
| Selden Research Ltd | Buxton | A rating |
| Select & Save Food & Wine | Essex | A rating |
| Select A Car | Leicester | A rating |
| Select and Save | London | A rating |
| SELECT CARE SERVICES LTD | LEICESTER | A rating |
| SELECT CHOICE COMMUNITY SUPPORT LTD | Harrogate | A rating |
| SELECT DENTAL CARE LIMITED | Middlesbrough | A rating |
| Select Equity Group UK Limited | London | A rating |
| SELECT EXPRESS LTD | LONDON | A rating |
| SELECT GB LIMITED | London | A rating |
| Select Global Events Ltd | Hove | A rating |
| Select K9 Security Ltd | Blackburn | A rating |
| Select Model Agency Limited | London | A rating |
| SELECT MOTOR COMPANY (MCR) LTD | Stockport | A rating |
| Select Offshore Ltd | Billericay | A rating |
| SELECT PIZZA INN LIMITED | London | A rating |
| SELECT PRINT LTD | Harrow | A rating |
| Select Property Group Limited | Alderley Edge | A rating |
| Select Retail Limited trading as Costcutter | Kelty | A rating |
| SELECT SALES TEAM LIMITED | Leeds | A rating |
| Select Service Partner UK Ltd | London | A rating |
| Select Specs Limited | Westgate on Sea | A rating |
| SELECT SUPPORT PARTNERSHIPS LTD | Blackburn | A rating |
| Select Supported Care Limited T/AS Hart Plain Care | Waterlooville | A rating |
| Select Surveys Limited | Sevenoaks | A rating |
| SELECT4 LIMITED | WEST YORKSHIRE | A rating |
| SELECTA SOL LTD | Manchester | A rating |
| Selected Property Limited | Southhall | A rating |
| Selected Work Facility Limited | London | A rating |
| Selectia Education Ltd | London | A rating |
| SELECTION INTERNATIONAL LIMITED | London | A rating |
| SELECTLINE SOLUTIONS LTD | Milton Keynes | A rating |
| SELECTRONICS PHONE AND COMPUTER REPAIRS LIMITED | Essex | A rating |
| SELEKT MOTORS LTD | Slough | A rating |
| SELEKT PIZZA INN HIGH ROAD LTD | Middlesex | A rating |
| SELENE MARINE UK LIMITED | Chelmsford | A rating |
| Seletia (HW) Limited | Eccles | A rating |
| Self Fulfilling Prophecy Limited | London | A rating |
| Self Funding Ltd | Bedford | A rating |
| Self Help Africa UK | Shrewsbury | A rating |
| Self Help Nottingham T/A Self Help UK | Nottingham | A rating |
| Self Mark Ltd | London | A rating |
| Self Service Ltd | London | A rating |
| Self Service Store | Hitchin | A rating |
| Self Service Technology Ltd | Willerby | A rating |
| SELF STORAGE PLACE LTD | Birmingham | A rating |
| Self-portrait ltd | London | A rating |
| Selfridges Retail Limited | London | A rating |
| Selhurst Evangelical Church | London | A rating |
| Selig UK Limited | Slough | A rating |
| SELIM TRADERS (UK) LTD T/A Unique Learning Advisor | LONDON | A rating |
| Selina Finance Limited | London | A rating |
| Selkirk Medical Practice | Selkirk | A rating |
| Sell & Repair It Limited | Weymouth | A rating |
| SELL & REPAIR LTD | Bognor Regis | A rating |
| Sell Through Digital Ltd | West Midlands | A rating |
| Sell2World International Limited | London | A rating |