| KOREA AEROSPACE INDUSTRIES UK OFFICE | Chester | A rating |
| Korea Creative Content Agency UK | london | A rating |
| Korea Exchange, Inc. UK Branch Office | London | A rating |
| Korea Housing Finance Corporation London Branch | London | A rating |
| Korea Investment & Securities Europe Ltd | London | A rating |
| Korea Investment Corporation London Office | London | A rating |
| KOREA LNG LIMITED, LONDON REPRESENTATIVE OFFICE | London | A rating |
| Korea Maritime Cooperation Center | London | A rating |
| Korea Money Brokerage Corporation, London Branch | London | A rating |
| Korea National Pension Service | London | A rating |
| Korea Tourism Organization | London | A rating |
| Korea Trade Centre, London | London | A rating |
| KOREA VENTURE INVESTMENT CORPORATION EUROPE OFFICE | London | A rating |
| Korean Air | LONDON | A rating |
| Korean Register of Shipping | London | A rating |
| Korean Reinsurance Company | London | A rating |
| KORLOY UK LIMITED | Exhall | A rating |
| Korn Ferry (UK) Limited | London | A rating |
| KOSE CORPORATION UK BRANCH | London | A rating |
| Kosmos Energy LLC | London | A rating |
| Kotak Mahindra (UK) Limited, | London | A rating |
| Koto Studio Ltd | London | A rating |
| Kowa Pharmaceutical Europe Co. Ltd. | Wokingham | A rating |
| KP Snacks Limited | Slough | A rating |
| KPIT TECHNOLOGIES (UK) LTD | COVENTRY | A rating |
| Kpler Limited | London | A rating |
| KPM ENGINEERING LTD | Lancs | A rating |
| KPMG IFRG Ltd | London | A rating |
| KPMG Ireland | Belfast | A rating |
| KPMG LLP | London | A rating |
| KPMG LLP (Local Hires) | London | A rating |
| KPMG US Tax Service (London) LLP | London | A rating |
| KPP Ventures Ltd | Brighton | A rating |
| KPSS (UK) Ltd | London | A rating |
| Kraken Technologies Limited | London | A rating |
| Kramp UK Ltd | Biggleswade | A rating |
| Krantz Limited | Rochester | A rating |
| Kratos Analytical Ltd | Manchester | A rating |
| Kratos Communications Limited | Gateshead | A rating |
| Krka UK Ltd | London | A rating |
| Kroll Advisory Ltd | London | A rating |
| Kroll Associates UK Limited | London | A rating |
| Kroll Bond Rating Agency UK Limited | London | A rating |
| Krones UK Ltd | Bolton | A rating |
| KSL Capital Partners International LLP | London | A rating |
| KSM Zeman Ltd | London | A rating |
| KTS Legal Ltd t/a KTS Legal | London | A rating |
| Kubach & Sambrook (Metals) Limited | Middlesex | A rating |
| Kubota (UK) Limited | Thame | A rating |
| KUBOTA Water and Environment Europe Ltd. | London | A rating |
| Kudan Limited | Bristol | A rating |
| Kuehne + Nagel Ltd | Feltham | A rating |
| KUKA Robotics UK Ltd | Wednesbury | A rating |
| Kuka Systems UK Limited | Halesowen | A rating |
| KUMAR ORGANIC PRODUCTS LTD | London | A rating |
| Kumho Tyre (UK) Ltd | Rugby | A rating |
| Kumon Europe & Africa Limited | Ealing | A rating |
| Kurita UK Limited | Livingston | A rating |
| KURY UK Ltd | Bristol | A rating |
| Kuwait Airways Company | West Drayton | A rating |
| KUWAIT FINANCE HOUSE PLC | London | A rating |
| Kuwait Oil Company K.S.C | London | A rating |
| Kuwait Petroleum Corporation | London | A rating |
| Kuwait Petroleum International Ltd | Woking | A rating |
| Kvadrat Ltd | London | A rating |
| Kvika Securities Ltd | London | A rating |
| KWA Analytics Ltd | London | A rating |
| KWASA Invest Limited | London | A rating |
| KWM Europe LLP | London | A rating |
| KWS UK Limited | Royston | A rating |
| KWT Global Ltd | London | A rating |
| Kx Advisors LLC | London | A rating |
| Kymco UK Ltd | Bridgend | A rating |
| Kyndryl UK Limited | London | A rating |
| Kynetec UK Ltd | Newbury | A rating |
| KYOBO LIFE LONDON OFFICE | LONDON | A rating |
| KYOCERA AVX Components Ltd | Camberley | A rating |
| KYOCERA Document Solutions (U.K.) Limited | Reading | A rating |
| Kyocera Fineceramics Ltd | Camberley | A rating |
| Kyodo News | London | A rating |
| Kyotec Polska UK | London | A rating |
| Kyowa Kirin Pharmaceuticals Development Limited | Scotland | A rating |
| KYRIBA UK LTD | London | A rating |
| Kyu Investment UK Limited | London | A rating |
| Kyuden International UK Ltd | London | A rating |
| L Catterton UK Advisors Limited | London | A rating |
| L-Acoustics UK Limited | London | A rating |
| L-GAM UK Advisors Limited | London | A rating |
| L.E.K. Consulting LLP | London | A rating |
| L'Oreal UK Ltd | London | A rating |
| L&C Consulting International Limited | London | A rating |
| L&G - Asset Management Limited | London | A rating |
| L&T Technology Service Limited | London | A rating |
| L3Harris Commercial Training Solutions Limited | Crawley | A rating |
| L3Harris Mapps Limited | Bristol | A rating |
| La Fosse Associates Ltd | London | A rating |
| La Mancha Services UK Limited | London | A rating |
| Labaton Keller Sucharow UK Limited | London | A rating |
| Lacoste UK Limited | London | A rating |
| Ladbrokes Betting & Gaming Ltd | London | A rating |
| LADERA TECHNOLOGY LTD | Reading | A rating |
| Ladies European Golf Venture Limited | Denham | A rating |
| LAIKA UK Films Limited | London | A rating |
| Laing O'Rourke PLC | Dartford | A rating |
| LALIVE (London) LLP | London | A rating |
| Lam Research Limited | Almondsbury | A rating |
| Lambda Therapeutic Limited | London | A rating |
| Lancashire Insurance Services Limited | London | A rating |
| Lancesoft Limited | London | A rating |
| Landell-Mills Ltd. | Trowbridge | A rating |
| Landesbank Baden-Wurttemberg | London | A rating |
| Landis + Gyr Ltd | Manchester | A rating |
| Landmark Properties UK Operations Ltd | London | A rating |
| Landmark Worldwide UK Limited | London | A rating |
| Lands' End Europe Limited | Oakham | A rating |
| Lang-AG Ltd | Leighton Buzzard | A rating |
| Langan International UK, Ltd | London | A rating |
| Langham Hall UK Services LLP | London | A rating |
| Langosteria London Limited | London | A rating |
| Lanier Theological Education Foundation | Kidlington | A rating |
| LANXESS Solutions UK Ltd | Manchester | A rating |
| LanzaTech UK Limited | Guildford | A rating |
| Larchfield Group Limited | Tonbridge | A rating |
| Larking Gowen LLP | Norwich | A rating |
| LASALLE INVESTMENT MANAGEMENT | London | A rating |
| LASER CLINICS UK MANAGMENT LTD | London | A rating |
| Laser Digital UK Ltd | London | A rating |
| LastMileXchange Ltd | London | A rating |
| LATAM Airlines Group S.A | London | A rating |
| Latentview Analytics UK Limited | London | A rating |
| LATHAM & WATKINS (LONDON) LLP | LONDON | A rating |
| Lattice Technologies Limited | London | A rating |
| Launchchange Operations Ltd | Solihull | A rating |
| Launchdarkly Ltd | Cheltenham | A rating |
| Laura Devine Solicitors Limited (trading as Laura Devine Immigration) | LONDON | A rating |
| Lavazza Professional UK Limited | BASINGSTOKE | A rating |
| Lawyers on Demand Limited | London | A rating |
| Lazard & Co., Services Limited | London | A rating |
| Lazard Asset Management Limited | London | A rating |
| LCH Partners (UK) Limited | London | A rating |
| LCM Corporate Services UK Ltd | London | A rating |
| LDF OPERATIONS LIMITED (t/a White Oak UK) | Chester | A rating |
| Le Cordon Bleu Limited | London | A rating |
| LE PETIT SAINT LIMITED | London | A rating |
| Lead Forensics Limited | Portsmouth | A rating |
| Leadenhall Capital Partners LLP | London | A rating |
| LEADER ELECTRONICS OF EUROPE LIMITED | Thatcham | A rating |
| Leaders' Quest Limited | London | A rating |
| Leadingmile Ltd | London | A rating |
| Lean Technologies Development (UK) Limited | London | A rating |
| Leanpath Ltd | London | A rating |
| Leap29 Holdings Ltd | Wilmslow | A rating |
| Lear Corporation | Coventry | A rating |
| Learning Pool | Derry | A rating |
| LearningMate Solutions (UK) | Amersham | A rating |
| LeasePlan UK Ltd | Slough | A rating |
| Lebara Limited | London | A rating |
| Lecico PLC | Bedford | A rating |
| Lectra UK Ltd | Albion Road | A rating |
| Lee Kum Kee (Europe) Ltd | London | A rating |
| LEEDS UNITED FOOTBALL CLUB LIMITED | Leeds | A rating |
| Left Lane UK Limited | London | A rating |
| Legal & General Resources Ltd | London | A rating |
| LegalVision Law UK Ltd | Manchester | A rating |
| Legendre UK Limited | London | A rating |
| Legends Sales & Marketing UK Limited | London | A rating |
| LEGO Company Ltd | Slough | A rating |
| Lego Digital Play Limited | LONDON | A rating |
| Legrand Electric Limited | Birmingham | A rating |
| Leica Biosystems Newcastle Ltd | Newcastle Upon Tyne | A rating |
| Leica Geosystems Limited | Milton Keynes | A rating |
| Leicester City FC | Leicester | A rating |
| Leidos Innovations Global, Inc. | London | A rating |
| Leidos Innovations UK Ltd | Glasgow | A rating |
| Leif Hoegh (UK) Limited | London | A rating |
| Lek Securities UK Limited | London | A rating |
| LEKO LABS UK LIMITED | Cambridge | A rating |
| LEMAN International Transport Limited | Normanton | A rating |
| LEMONGRASS CONSULTING LIMITED | READING | A rating |
| Lend & Borrow Trust Company Limited | Wadebridge | A rating |
| LendLease Europe Holdings Limited | London | A rating |
| Lendscape Limited | London | A rating |
| Lenovo Technology (United Kingdom) Limited | Farnborough | A rating |
| Lenzing Fibers Grimsby Limited | Grimsby | A rating |
| Leo Burnett Limited | London | A rating |
| LEO Laboratories Ltd | Maidenhead | A rating |
| Leonard Cheshire Disability | London | A rating |
| LEONARDO BELGIUM SA | Elstree | A rating |
| Leonardo UK Ltd | Basildon | A rating |
| LEONI Wiring Systems UK Limited | Newcastle | A rating |
| Leonis Principal Ltd | Mayfair | A rating |
| Leonteq Securities (Europe) GmbH | London | A rating |
| Les Ambassadeurs Club Limited | London | A rating |
| Les Mills UK Fitness Limited | London | A rating |
| Leumi UK Group Limited | London | A rating |
| Leversys Ltd | London | A rating |
| LEVIDIAN NANOSYSTEMS LIMITED | CAMBRIDGE | A rating |
| Levis Strauss (U.K.) Limited | Northampton | A rating |
| Leviton Manufacturing UK Ltd | Glenrothes | A rating |
| Levmet (UK) Limited | London | A rating |