| Therakos (UK) Limited | Staines-Upon-Thames | A rating |
| THERAMEX HQ UK LIMITED | London | A rating |
| Thermal Energy International (UK) Ltd | BRISTOL | A rating |
| Thermax Europe Ltd | Milton Keynes | A rating |
| Therme Group Services (UK) Limited | Richmond | A rating |
| Therme North Limited | Manchester | A rating |
| Thermo Electron Management Services | Hemel Hempstead | A rating |
| Thermotraffic UK Ltd | Essex | A rating |
| ThetaRay Private Limited | London | A rating |
| THI Investments UK Limited | London | A rating |
| THINK INVESTMENTS EUROPE LLP | London | A rating |
| ThinkAnalytics Ltd | Glasgow | A rating |
| Third Bridge Group Limited | London | A rating |
| Third Generation Environmentalism Ltd | London | A rating |
| Thoma Bravo UK Advisers LLP | London | A rating |
| THOMAS CLIFFORD LTD | Leeds | A rating |
| Thomas Cook Tourism (UK) Company Ltd | London | A rating |
| Thomas Miller (UK) Holdings Company Ltd | London | A rating |
| Thompson Aero Seating | Portadown | A rating |
| Thomson Reuters (Professional) UK Limited | Canary Wharf | A rating |
| Thorlabs Limited | Ely | A rating |
| Thorn Lighting Ltd | Spennymoor | A rating |
| Thorn Security Limited | Sunbury On Thames | A rating |
| Thornton & Ross Limited | Nr Huddersfield | A rating |
| Thornton Tomasetti Ltd | London | A rating |
| Thorogood Associates Limited | London | A rating |
| Thoucentric Limited | Harrow | A rating |
| ThoughtClan Technologies (UK) LTD | Evesham | A rating |
| ThoughtSpot EMEA Ltd | London | A rating |
| ThoughtWorks Ltd | London | A rating |
| Threadneedle Management Services Limited | LONDON | A rating |
| Thredd (UK) Limited | London | A rating |
| THREE CROWNS (SERVICES) LLP | LONDON | A rating |
| Three Six Zero GRP Limited | London | A rating |
| Three60 Operations Services Limited | London | A rating |
| Thrive Operations Limited | Luton | A rating |
| Thule Outdoor Ltd | Haverhill | A rating |
| Thunderful Games Limited | Woking | A rating |
| Thurloe Hotels Ltd | London | A rating |
| Tianjin Airlines Co Ltd | Hounslow | A rating |
| Tibra Trading Europe Ltd | London | A rating |
| Ticketmaster UK Limited | London | A rating |
| TIES AND MORE LTD | Lewisham | A rating |
| Tieto Great Britain Limited | Aberdeen | A rating |
| Tiffany & Co . Limited | London | A rating |
| Tiger Analytics Consulting Ltd | London | A rating |
| TigerRisk Partners (UK) Limited | London | A rating |
| TIGI International Limited (Trading As Elida Beauty) | London | A rating |
| Tikehau Capital Europe Limited | London | A rating |
| TikTok Information Technologies UK Limited | London | A rating |
| Tile Mountain Ltd | Stoke on Trent | A rating |
| Tillomed Laboratories Limited | Luton | A rating |
| Tilray Brands UK Ltd | London | A rating |
| Timac Agro UK Ltd | Harpenden | A rating |
| Time and Data Systems International Ltd | Poole | A rating |
| Time Magazine UK Limited | London | A rating |
| Time Out Group PLC | London | A rating |
| Time Shipping Limited | London | A rating |
| Times Internet (UK) Ltd | London | A rating |
| Times24 UK Limited | London | A rating |
| Timo Eva Wellness UK Limited | London | A rating |
| Tindall Riley & Co Limited | London | A rating |
| Tinyme Limited | Slough | A rating |
| Tioxide Materials Limited | Stockton-on-Tees | A rating |
| Tipalti Europe Limited | London | A rating |
| Tishman Speyer Properties UK Limited | London | A rating |
| TISSOT INDUSTRY UK Ltd | Crydon | A rating |
| Titan Wood Limited | LONDON | A rating |
| TJX UK | Watford | A rating |
| TK Airport Solutions S.A. | Slough | A rating |
| TK Elevator UK Ltd. | Nottinghamshire | A rating |
| TLS Contact (UK) Ltd | London | A rating |
| TMD Friction Holdings (UK) Ltd | Cleckheaton | A rating |
| TMEIC EUROPE LIMITED | Uxbridge | A rating |
| TMF Global Services (UK) Limited | London | A rating |
| TMG Marchesini UK Ltd | Leighton Buzzard | A rating |
| TMI Associates London LLP | London | A rating |
| TMX Exchange Services Limited | London | A rating |
| TNG Technology Consulting UK Ltd. | Oxford | A rating |
| Toasttab UK Limited T/A Toast | London | A rating |
| Tobii Dynavox Limited | Warwick | A rating |
| TodayTix, Ltd | London | A rating |
| Todd & Duncan Limited | Kinross | A rating |
| Toggle Software Services UK Ltd. | London | A rating |
| Tokai Tokyo Securities Europe Limited | London | A rating |
| Token.IO Ltd | London | A rating |
| Tokio Marine Kiln Insurance Services Ltd | London | A rating |
| Tokyo Electric Power Company Holdings Incorporated | London | A rating |
| Tokyo Electron Europe Limited | Crawley | A rating |
| Tokyo Gas United Kingdom Ltd. | London | A rating |
| Tom Ford Studio Limited | London | A rating |
| Tomoe Valve Ltd | Newport | A rating |
| TOMRA Collection Ltd. | London | A rating |
| TomTom Software Limited | London | A rating |
| TOMY UK Co,, Ltd. (T/A TOMY Europe) | Exeter | A rating |
| TONIES UK LIMITED | London | A rating |
| Tony Gee and Partners LLP | Esher | A rating |
| Too Good To Go Ltd | London | A rating |
| Top Tier Capital Partners (UK) Limited | London | A rating |
| TOPCON GREAT BRITAIN MEDICAL, BRANCH OF TOPCON EUROPE MEDICAL B.V | Newbury | A rating |
| Topgolf Limited | Shepperton | A rating |
| Topham Guerin Limited | London | A rating |
| TOPPAN Security Limited | Basingstoke | A rating |
| Topps Europe Limited | Milton Keynes | A rating |
| Toptour Europe Limited | London | A rating |
| Toray Textiles Europe Ltd | Mansfield | A rating |
| Torch Partners Corporate Finance Limited | London | A rating |
| Torishima Europe Limited | Glasgow | A rating |
| TORM Plc | London | A rating |
| Toro UK Ltd | Bishops Stortford | A rating |
| TORQ COMMODITIES (UK) LTD | London | A rating |
| TORRECID UK - SURCOTECH LTD | Newent | A rating |
| Torrent Pharma (UK) Ltd | Crawley | A rating |
| Torry Harris Business Solutions ( Europe) Limited | Bristol | A rating |
| Torus Financial Limited | London | A rating |
| Toshiba Europe Limited | Staines-Upon-Thames | A rating |
| Toshiba Europe Limited (Bristol) | Bristol | A rating |
| Toshiba Europe Limited (Cambridge) | Cambridge | A rating |
| Toshiba Global Commerce Solutions (U.K.) Limited | Chertsey | A rating |
| Toshiba International (Europe) Limited | Staines Upon Thames | A rating |
| Toshiba TEC UK Imaging Systems Ltd | Chertsey | A rating |
| Total System Services Processing Europe Ltd | York | A rating |
| Total Waste Management Alliance Limited | Aberdeen | A rating |
| TotalEnergies E&P UK Limited | Westhill | A rating |
| TotalEnergies Gas and Power Limited | Tadworth | A rating |
| TotalEnergies Marketing UK Ltd | London | A rating |
| TotalEnergies Renewables UK Ltd | Redhill | A rating |
| TOTO EUROPE GMBH (UK BRANCH) | LONDON | A rating |
| Touax UK Limited | London | A rating |
| Touchdown PR Limited | Basingstoke | A rating |
| TouchTunes UK Ltd | London | A rating |
| Tourism Australia | London | A rating |
| Tourvest Destination Management UK Limited | Woking | A rating |
| TOWER BRIDGE INTERNATIONAL SERVICES L.P. | LONDON | A rating |
| Tower Research Capital Europe Limited | London | A rating |
| TowerBrook Capital Partners (U.K.) LLP | London | A rating |
| TowerPros Limited | Slough | A rating |
| Towers Watson Limited | Surrey | A rating |
| Toyota | Derby | A rating |
| Toyota Connected Europe Limited | London | A rating |
| Toyota Financial Services (UK) PLC | Epsom | A rating |
| Toyota Gazoo Racing Simulation UK | Epsom | A rating |
| Toyota Tsusho Automobile London Holdings Ltd | London | A rating |
| Toyota Tsusho UK Ltd | London | A rating |
| TP ICAP GROUP SERVICES LIMITED | LONDON | A rating |
| TPBI UK Limited | Newcastle under Lyme | A rating |
| TPG EUROPE, LLP | LONDON | A rating |
| TPI Composites UK Company Limited | Birmingham | A rating |
| TR7 Ltd | Cheltenham | A rating |
| Trace First Limited | County Down | A rating |
| Trace One Ltd | Hemel Hempstead | A rating |
| Tracelink Europe Limited | Woking | A rating |
| Tracerco Ltd | Billingham | A rating |
| Tract Capital Management UK Ltd | London | A rating |
| Tractebel France - Coyne et Bellier | London | A rating |
| Tradebe Management Limited | Marlow | A rating |
| Tradebridge Financial Technologies Limited | London | A rating |
| TRADELINK WOOD PRODUCTS LTD. | London | A rating |
| Tradelink Worldwide Limited | London | A rating |
| Tradepoint Systems UK Ltd | London | A rating |
| Tradeshift Network Limited | London | A rating |
| Tradeweb Europe Limited | London | A rating |
| Tradify (UK) Limited | London | A rating |
| Trading 212 UK Ltd | London | A rating |
| Trading Technologies UK Limited | London | A rating |
| Tradition (UK) Limited | London | A rating |
| TraffiSafe Limited | Alton | A rating |
| Trafigura | London | A rating |
| TrailRunner International UK Limited | London | A rating |
| TRAINFX LIMITED | DERBY | A rating |
| Training The Street UK, LLC ("UK BRANCH") | St Albans | A rating |
| Tramontina United Kingdom Limited | London | A rating |
| Trane (UK) Ltd | Basingstoke | A rating |
| Trane UK Limited | Basingstoke | A rating |
| Trans Indus Limited | London | A rating |
| Transaction Network Service UK Limited | Sheffield | A rating |
| Transatlantique Private Wealth (UK) Limited | London | A rating |
| TRANSCAL LIMITED | LIVINGSTON | A rating |
| Transcend Packaging Ltd | Ystrad Mynach | A rating |
| Transcend Street Solutions UK Limited | London | A rating |
| TRANSDEV PLC | Keighley | A rating |
| Transfer Rapid Limited | London | A rating |
| Transfesa UK Limited | Barking | A rating |
| Transition Bio Limited | Cambridge | A rating |
| TRANSMIT SECURITY UK LTD | Reading | A rating |
| Transperfect Translations Limited | London | A rating |
| Transputec Limited | Wembley | A rating |
| TransRe London Services Limited | London | A rating |
| TRANSUNION INFORMATION GROUP LIMITED | Leeds | A rating |
| Travel Up Group PLC | Reading | A rating |
| Travelers Management Ltd | Surrey | A rating |
| Travelex Central Services Limited | London | A rating |
| Travelfusion Ltd | London | A rating |
| Travelopia Holdings Limited | Surbiton | A rating |
| Travelport International Limited | Langley | A rating |
| Travelzoo (Europe) Limited | London | A rating |
| Travis Perkins Plc | Northampton | A rating |
| Travix Travel UK Ltd | London | A rating |
| Trax Retail Ltd | London | A rating |
| Trayport Limited | London | A rating |