| K2 Intelligence Limited | London | A rating |
| K2 Partnering Solutions Holding Co Ltd | London | A rating |
| K3 Business Technology Group plc | Manchester | A rating |
| Kaar Technologies UK Limited | Huddersfield | A rating |
| Kabushiki Kaisha Nikkei B.P. trading as Nikkei Business Publications Inc | London | A rating |
| Kadence International Ltd | London | A rating |
| Kaihua UK Limited TAs Cumberland Hotel | Eastbourne | A rating |
| Kaiser Associates International, Inc | London | A rating |
| Kaizen UK Consulting Limited | London | A rating |
| Kajima Europe Limited | London | A rating |
| KAL Software UK | Edinburgh | A rating |
| KALISAN UK LTD | Milnthorpe | A rating |
| Kallidus Limited | Bristol | A rating |
| Kalmar Limited | Bicton Heath | A rating |
| Kaltura Europe Limited | London | A rating |
| Kaluza Ltd | London | A rating |
| KalVista Pharmaceuticals Limited | Salisbury | A rating |
| Kalyan Gold and Diamond Jewellery Limited | Leicester | A rating |
| Kammac Limited | Cheshire | A rating |
| Kampmann UK Ltd | Shepperton | A rating |
| Kanadevia Inova UK Limited | Farnborough | A rating |
| Kandji UK Limited | London | A rating |
| Kandou Bus Limited | Northampton | A rating |
| Kannegiesser UK Limited | Banbury | A rating |
| Kanpai (London) Food & Beverage Management Co., Ltd. | London | A rating |
| KANSAI ELECTRIC POWER FTS PTE. LTD. (LONDON BRANCH) | London | A rating |
| Kantar Public UK Limited | London | A rating |
| Kao (UK) Limited | London | A rating |
| Kapital Media London Limited | London | A rating |
| Kaplan Financial Limited | London | A rating |
| KAPPA Training and Consulting Services Ltd | Reigate | A rating |
| Karaca Porcelain UK Limited | Swindon | A rating |
| KARBONE LIMITED | LONDON | A rating |
| Karsten UK Ltd | Spalding | A rating |
| KASAI UK LTD | Washington | A rating |
| Kason Europe Limited | Macclesfield | A rating |
| Kaspersky Lab UK Limited | London | A rating |
| Kataman UK Limited | Bristol | A rating |
| Katten Muchin Rosenman UK LLP | London | A rating |
| Kaviari UK Limited | London | A rating |
| Kawai UK Ltd | Milton Keynes | A rating |
| Kawasaki Heavy Industries (UK) Ltd. | London | A rating |
| Kawasaki Motors UK | Bourne End | A rating |
| Kawasaki Precision Machinery (UK) Ltd | Plymouth | A rating |
| Kayak Software (UK) Limited | London | A rating |
| KAZ Minerals Limited | London | A rating |
| Kazmortransflot UK Ltd | London | A rating |
| KBC Bank NV | London | A rating |
| KBC Process Technology Ltd | Walton on Thames | A rating |
| KCA Deutag Drilling Ltd | Portlethen | A rating |
| KCI Medical Limited | Loughborough | A rating |
| KDDI Europe Limited | London | A rating |
| KDMS Payments Limited | London | A rating |
| KEB HANA BANK | LONDON | A rating |
| Kee Safety Limited | Birmingham | A rating |
| Keensight Capital (UK) Ltd | London | A rating |
| Kegstar Ltd | Milton Keynes | A rating |
| Keith Spicer Limited | Wimborne | A rating |
| Keller Group Plc | London | A rating |
| Kellogg Brown & Root (UK) Ltd | Surrey | A rating |
| Kellogg Brown and Root Solutions Limited | Leatherhead | A rating |
| Kellogg U.K. Holding Company Limited | Salford | A rating |
| KELLTON TECH (UK) LIMITED | London | A rating |
| KELLY OCG UK LTD | Telford | A rating |
| KEMEL EUROPE LTD | WASHINGTON | A rating |
| Kemin UK Limited | Southport | A rating |
| Kenilworth Creations LTD | Newcastle Upon Tyne | A rating |
| Kennedy Wilson UK Limited | London | A rating |
| Kennedys Law LLP | London | A rating |
| KENSHOO (UK) LTD | LONDON | A rating |
| Kensington Park School Limited t/a Kensington Park School | London | A rating |
| Kensington Press Limited | Essex | A rating |
| Kent Energies UK Ltd | Woking | A rating |
| Kentucky Fried Chicken (Great Britain) Limited | Woking | A rating |
| KENVUE EMEA SERVICES LIMITED | Reading | A rating |
| Kenwood Limited | Havant | A rating |
| Kepler Cheuvreux | London | A rating |
| KEPLER GROUP EMEA LIMITED | London | A rating |
| Kepler Interactive Limited | LONDON | A rating |
| Kerakoll U.K. Limited | Leyland | A rating |
| KEREN BARTOV ADVANCED SKIN CARE LONDON LTD | London | A rating |
| Kering UK Services Limited | London | A rating |
| Kerogen Capital (UK) Limited | London | A rating |
| Kerridge Commercial Systems Ltd | Hungerford | A rating |
| Kerry Ingredients UK Ltd | Bristol | A rating |
| Kervan Gida UK Limited | London | A rating |
| Kerzner International Marketing (UK) Limited | London | A rating |
| Keter UK Limited | Banbury | A rating |
| Keva UK Limited | Edgware | A rating |
| Kexim Bank (UK) Limited | London | A rating |
| Keyence (UK) Ltd | Uxbridge | A rating |
| Keyloop (UK) Limited | Reading | A rating |
| KeyMed (Medical & Industrial Equipment) Ltd | Southend-on-Sea | A rating |
| Keyrus UK | London | A rating |
| Keysight Technologies UK Limited | Wokingham | A rating |
| Keystone Europe Limited | London | A rating |
| KfW IPEX-Bank GmbH, London Branch | London | A rating |
| KGHL Research (UK) Ltd | London | A rating |
| KGS Fire & Security UK Limited | Milton Keynes | A rating |
| Kheiron Medical Technologies Ltd | London | A rating |
| KHS UK LTD | Solihull | A rating |
| Kia Motors (UK) Ltd | Walton-On-Thames | A rating |
| Kido Schools UK Limited | Streatham | A rating |
| Kier Group plc | Salford | A rating |
| Kiklo Spaces Limited | Petersfield | A rating |
| Kiln Technologies Limited | London | A rating |
| KIMAK SYSTEMS & DESIGN UK LIMITED | London | A rating |
| Kimberly Clark Europe Ltd | Tadworth | A rating |
| Kimberly-Clark European Services Ltd | Tadworth | A rating |
| Kimberly-Clark Ltd | Tadworth | A rating |
| Kimble Applications Limited t/a Kantata | London | A rating |
| Kin&Co Enterprises Limited | Shoreham-By-Sea | A rating |
| Kinaxis UK Limited | Bristol | A rating |
| Kindeva Drug Delivery Limited | Loughborough | A rating |
| Kindred (London) Limited | London | A rating |
| Kinectrics UK Limited | Guildford | A rating |
| Kinetic Technologies Europe Limited | Edinburgh | A rating |
| King & Shaxson Limited | London | A rating |
| King & Spalding International LLP | London | A rating |
| King Street (Europe) LLP | London | A rating |
| King William St Limited | London | A rating |
| Kingdom Hotel Investments (UK) Ltd | London | A rating |
| Kingfisher PLC | London | A rating |
| Kingsley Gate Partners U.K. Ltd | London | A rating |
| Kingspan Insulation Limited | Pembridge | A rating |
| KINGSTON TECHNOLOGY EUROPE CO LLP | SUNBURY ON THAMES | A rating |
| KINOKUNIYA PUBLICATIONS SERVICE OF LONDON CO. LTD. | London | A rating |
| Kinseed Limited | Uxbridge | A rating |
| Kintetsu World Express UK Limited | Colbroook | A rating |
| Kintyre Development Company Limited | Argyll | A rating |
| KIOXIA Technology UK Ltd | Abingdon | A rating |
| Kirby Group Engineering (UK) Ltd | Brentford | A rating |
| Kirkland & Ellis International LLP | London | A rating |
| Kitagawa Europe Limited | Salisbury | A rating |
| Kitchen Range Foods | Huntingdon | A rating |
| KITRI Limited | London | A rating |
| Kivnon UK Ltd | London | A rating |
| KLA Corporation UK Limited | Newport | A rating |
| Klarna Bank AB UK Branch | London | A rating |
| Klaviyo Ltd | London | A rating |
| KLDiscovery Limited | London | A rating |
| Klesch and Company Limited | London | A rating |
| Klevu UK Limited | London | A rating |
| Klick Health UK Private Limited | London | A rating |
| KLINE HILL PARTNERS (UK) LIMITED | London | A rating |
| KLM UK Engineering Limited | Norwich | A rating |
| KLN Freight (UK) Limited | Manchester | A rating |
| KLOCKNER PENTAPLAST LIMITED | Newport | A rating |
| Klohn Crippen Berger (UK) Limited | Heworth Green | A rating |
| KLP Management Limited | London | A rating |
| Kluber Lubrication Great Britain Ltd | Huddersfield | A rating |
| KM UK Services Limited | London | A rating |
| Knauf (UK) GmbH | Sittingbourne | A rating |
| KNAUF INSULATION LIMITED | ST HELENS | A rating |
| KNAV Advisory Limited | Harrow | A rating |
| KNAV LIMITED | Harrow | A rating |
| KNAV Services Limited | Harrow | A rating |
| KNDS DEFENCE UK LIMITED | Stockport | A rating |
| Knight Frank LLP | London | A rating |
| Knight Piesold Limited | London | A rating |
| KNIGHTSBRIDGE SCHOOLS INTERNATIONAL LIMITED | London | A rating |
| Knoll International Limited | London | A rating |
| Knorr-Bremse Rail Systems (UK) Limited | Melksham | A rating |
| Knorr-Bremse Systems for Commercial Vehicles Ltd | Bristol | A rating |
| Knowcross Limited | London | A rating |
| Knownorigin Labs Limited | Manchester | A rating |
| Knoxed Limited | Kidlington | A rating |
| Kobayashi Healthcare Europe, Ltd. | London | A rating |
| KOBELCO ECO-SOLUTIONS CO., LTD | London | A rating |
| KoBold Metals UK Limited | London | A rating |
| Kobre & Kim (UK) LLP | London | A rating |
| Koch Engineered Solutions Limited | Stoke on Trent | A rating |
| Koch Fertilizer International Limited | London | A rating |
| Koch Supply and Trading Company | London | A rating |
| Kodak Limited | Watford | A rating |
| Koei Tecmo Europe Ltd | Letchworth Garden City | A rating |
| Koerber Supply Chain Limited | Heathrow | A rating |
| Kofax Northern Ireland Ltd | Londonderry | A rating |
| Kohlberg Kravis Roberts & Co. Partners LLP | London | A rating |
| Kohler International Holdings Limited | Gloucester | A rating |
| Kohler Mira Limited | Cheltenham | A rating |
| Kohn Pedersen Fox Associates International PA | London | A rating |
| Kohort Software Limited | London | A rating |
| Kohyo UK Ltd | London | A rating |
| Koito Europe Ltd | Droitwich Spa | A rating |
| KOLAK SNACK FOODS LTD | London | A rating |
| Komatsu UK Ltd | Chester-le-Street | A rating |
| Komi App Limited | London | A rating |
| Konami Digital Entertainment B.V. | Windsor | A rating |
| KONE Plc | Woking | A rating |
| Konecranes Demag UK Ltd | Ashby De La Zouch | A rating |
| Konfloor Ltd | Armagh | A rating |
| Kongsberg Actuation Systems Limited | Normanton | A rating |
| Kongsberg Maritime Ltd | Westhill | A rating |
| Konica Minolta Business Solutions (UK) Ltd | Basildon | A rating |
| Konrad-Adenauer-Stiftung UK Limited | London | A rating |
| Kontiki Capital Management (UK) Limited | London | A rating |
| Konverge Technologies Limited | London | A rating |
| Kookmin Bank Co Ltd London Branch | London | A rating |
| KORE.AI UK LIMITED | London | A rating |