| MINMETALS IRON & STEEL UK LTD | LONDON | A rating |
| Minova International Ltd. | Addlestone | A rating |
| MINT MANAGEMENT TECHNOLOGY UK (PTY) LIMITED | England | A rating |
| Mintec Limited | Bourne End | A rating |
| Mintel Group Ltd | London | A rating |
| Minter Ellison | London | A rating |
| Minth Automotive (UK) Company Ltd | Sunderland | A rating |
| MINTZ GROUP UK LTD | LONDON | A rating |
| Minu Payment Solutions UK Ltd | Oxford | A rating |
| MiQ Digital Limited | London | A rating |
| Mirabaud Asset Management Limited | London | A rating |
| MIRACLE INTERNATIONAL CONTRACTING & TRADING CO. LTD | Bristol | A rating |
| Mirador Analytics Limited | Melrose | A rating |
| Mirae Asset Securities (UK) Ltd. | London | A rating |
| Mirai Power Europe Limited | London | A rating |
| Mirakl Ltd | London | A rating |
| Mirantis UK Limited | Reading | A rating |
| Mirastar Real Estate Investment Management Limited | London | A rating |
| Mirion Technologies (IST) Limited | Farnborough | A rating |
| Miro EMEA UK Ltd. | London | A rating |
| Miro Technologies Limited | Bristol | A rating |
| Miroma International Limited | London | A rating |
| Mirova | London | A rating |
| Mirova UK Limited | London | A rating |
| MISC Berhad (UK) Limited | London | A rating |
| Mission Aviation Fellowship International | Ashford | A rating |
| Mission Foods Europe | Middlesex | A rating |
| Mister Men Limited | London | A rating |
| Mistral AI UK Limited | London | A rating |
| Mistras Group Limited | Cambridge | A rating |
| Mitie Group Plc | Glasgow | A rating |
| Mitiga-UK Ltd. | London | A rating |
| Mitra Innovation Limited | London | A rating |
| Mitratech (UK) Limited | Burnham | A rating |
| Mitsubishi Chemical UK Limited | Hull | A rating |
| Mitsubishi Corporation International (Europe) Plc | London | A rating |
| Mitsubishi Corporation London Branch | London | A rating |
| Mitsubishi Electric Air Conditioning Systems Europe Ltd | Livingston | A rating |
| Mitsubishi Electric Corporation - UK office | London | A rating |
| Mitsubishi Electric Europe B.V. | Hatfield | A rating |
| Mitsubishi Estate London Limited | London | A rating |
| Mitsubishi HC Capital UK PLC | Staines upon Thames | A rating |
| Mitsubishi Heavy Industries EMEA, Ltd. | London | A rating |
| Mitsubishi Materials Corporation, London Office | London | A rating |
| Mitsubishi Pencil Co UK Ltd | Milton Keynes | A rating |
| Mitsubishi Power EMEA, Ltd | London | A rating |
| Mitsubishi UFJ Asset Management (UK) Ltd. | London | A rating |
| Mitsubishi UFJ Baillie Gifford Asset Management Limited | Edinburgh | A rating |
| Mitsubishi UFJ Trust and Banking Corporation | London | A rating |
| MITSUI & CO. ENERGY TRADING SINGAPORE PTE. LTD. (LONDON BRANCH) | London | A rating |
| Mitsui & Co. Europe Ltd | London | A rating |
| Mitsui Bussan Commodities Ltd | London | A rating |
| Mitsui Components Europe Limited | Ammanford | A rating |
| Mitsui E&S Machinery Europe Limited | London | A rating |
| Mitsui Fudosan (U.K.) Ltd | London | A rating |
| Mittal Investments UK Limited | London | A rating |
| MITUTOYO (UK) LTD | Andover | A rating |
| Miura & Partners UK Limited | London | A rating |
| Mivan Marine Ltd | Antrim | A rating |
| MiX Telematics Europe Ltd | Birmingham | A rating |
| Mixpanel UK Ltd | Bristol | A rating |
| Mizuho Bank, Ltd. | London | A rating |
| Mizuho EMEA Corporate Services Limited | London | A rating |
| Mizuho International plc | London | A rating |
| Mizuno Corporation (UK) | Wokingham | A rating |
| MIZUNO CORPORATION UK LIMITED | Wokingham | A rating |
| Mizuno Gakuen London Limited | London | A rating |
| MJES MEC. Y PTAS. EN MARCHA UK, LIMITED | Edinburgh | A rating |
| MKI (U.K.) ,LTD | London | A rating |
| MKP Capital Europe LLP | London | A rating |
| ML Photonic Limited | Dunfermline | A rating |
| MLL LEGAL LLP | London | A rating |
| MM Packaging Deeside Ltd | Deeside | A rating |
| MNEMONIC UK | London | A rating |
| MOA Benchmarking Limited | Slinfold | A rating |
| Mobico Group PLC | Birmingham | A rating |
| Mobileum UK Limited | Bristol | A rating |
| Mobis Parts Europe (UK) | Dordon | A rating |
| Modaxo Group UK Limited | Chippenham | A rating |
| Modern Paper Limited | Erith | A rating |
| Modern-Expo UK Limited | Kettering | A rating |
| Modetour Network UK Ltd | LONDON | A rating |
| MODS Management Ltd | Aberdeen | A rating |
| Modus Outcomes Limited | Cheltenham | A rating |
| Moet Hennessy UK Ltd | London | A rating |
| Moeve Chemicals UK Limited | London | A rating |
| Moffatt & Nichol, London | London | A rating |
| Mogrify Limited | Cambridge | A rating |
| Mohari Services UK Limited | London | A rating |
| Mojo Rental UK Ltd | Wrotham | A rating |
| MOL (EUROPE AFRICA) LTD | London | A rating |
| MOL Logistics (UK) Limited | West Drayton | A rating |
| MOL TECHNO-TRADE, LTD. EUROPEAN BRANCH | London | A rating |
| MOLBREEDING BIOTECHNOLOGY LTD | Harlow | A rating |
| Molecular Products Ltd | Harlow | A rating |
| Mollie B.V. | London | A rating |
| Molnlycke Healthcare | Milton Keynes | A rating |
| Moloco UK limited | London | A rating |
| Molson Coors Brewing Company (UK) Limited | Burton on Trent | A rating |
| Molton Brown Ltd | Bishop's Stortford | A rating |
| Molymet Services Limited | London | A rating |
| Momentive Performance Materials Ltd | Bolton | A rating |
| Momentum Activating Demand Limited | London | A rating |
| Momentum Global Investment Management Limited | London | A rating |
| Momentum Services Ltd | London | A rating |
| Momentus Technologies Group Limited | London | A rating |
| Monarch Alternative Capital (Europe) Ltd | London | A rating |
| Monashee International LLP | London | A rating |
| Monavate Holdings Limited | Duxford | A rating |
| MONCLER (UK) LIMITED | London | A rating |
| monday.com 2020 UK Ltd | London | A rating |
| Mondelez UK Limited | Middlesex | A rating |
| Mondi PLC | Weybridge | A rating |
| MONETARY AUTHORITY OF SINGAPORE | LONDON | A rating |
| Monex Europe Limited | LONDON | A rating |
| MongoDB UK Limited | London | A rating |
| Monocle Solutions Ltd | London | A rating |
| Monocon International Refractories Ltd | Doncaster | A rating |
| Monopo London Ltd | London | A rating |
| MONOTYPE LTD | London | A rating |
| Monster Energy Europe Limited | Greenford | A rating |
| Montagu Full Potential Partners LLP | London | A rating |
| Montagu Private Equity LLP | London | A rating |
| Montaze Broz LTD | Rickmansworth | A rating |
| Montieth & Company Global PR Limited | London | A rating |
| Monty's Bakehouse UK Limited | South Nutfield | A rating |
| Monzo Bank Ltd | London | A rating |
| MOO Print Limited | London | A rating |
| Moody's Analytics UK Ltd | London | A rating |
| Moody's Investors Service Ltd | London | A rating |
| Moody's Shared Services UK Limited | London | A rating |
| Moog Controls Limited | Tewkesbury | A rating |
| Moomenn Ltd | Walton on thames | A rating |
| Moonfare UK Limited | London | A rating |
| Moonvalleyai Ltd | London | A rating |
| Moonz Orthodontics Ltd | London | A rating |
| Moore Kingston Smith LLP | London | A rating |
| MOORIM UK LTD | NEW MALDEN | A rating |
| Moose Toys Ltd | St Columb Major | A rating |
| Moove Lubricants Limited | Gravesend | A rating |
| Morae Global UK Limited | London | A rating |
| More Contract UK Limited | London | A rating |
| Morgan Advanced Materials plc | Windsor | A rating |
| Morgan Stanley UK Limited | London | A rating |
| Morgan Technical Ceramics Limited | Stourport-on-Severn | A rating |
| MORGAN, LEWIS & BOCKIUS UK LLP | LONDON | A rating |
| Morningstar Europe Ltd | London | A rating |
| Morphe Cosmetics Ltd | London | A rating |
| Morphean International Limited | Birmingham | A rating |
| Morrells Woodfinishes Limited | Stockport | A rating |
| Morrison & Foerster (UK) LLP | London | A rating |
| MORRISON INFRASTRUCTURE (UK) LIMITED | London | A rating |
| Morse Micro Limited | Cambridge | A rating |
| Mosaic Management Services Limited | London | A rating |
| Mosaic Syndicate Services Limited | London | A rating |
| Most Friendship UK Limited | St. Albans | A rating |
| MOSTOSTAL PULAWY UK | London | A rating |
| MOSTOSTAL ZABRZE REALIZACJE PRZEMYSLOWE S.A. | Salford | A rating |
| Mother London Limited | London | A rating |
| Motion Applied Limited | Woking | A rating |
| Motive Technology UK Limited | London | A rating |
| Motive UK Advisors LLP | London | A rating |
| Moto Direct Limited | South Normanton | A rating |
| Motorola Solutions UK Limited | London | A rating |
| Mott MacDonald Ltd | London | A rating |
| Mount Street Portfolio Advisers GmbH | London | A rating |
| Mountbatten Programmes Ltd | London | A rating |
| MOUNTPARK PROPERTIES LIMITED | LONDON | A rating |
| Mourant Services (UK) Limited | London | A rating |
| Mourik UK Limited | Thornaby | A rating |
| Movable Limited | London | A rating |
| MOVATE UK LIMITED | Ringwood | A rating |
| Movember Europe | London | A rating |
| MovePlan Limited | London | A rating |
| Movus Logistics Limited | London | A rating |
| Mowi Scotland Limited | Fort William | A rating |
| Moy Park Ltd | Craigavon | A rating |
| Mphasis UK Limited | London | A rating |
| MPower Plus UK Ltd | London | A rating |
| MPRD Limited | Milton Keynes | A rating |
| MPT Ashtead Limited | London | A rating |
| MPT UK Services Limited | London | A rating |
| MRA Search Limited | London | A rating |
| MRC Global (UK) Limited | Cleckheaton | A rating |
| MRI Software Limited | London | A rating |
| MS Amlin Corporate Services Limited | London | A rating |
| MSA Mining Consulting UK Ltd | Cardiff | A rating |
| MSBC SOLUTIONS (UK) LIMITED | ELSTREE | A rating |
| MSC Cruise Management (UK) Ltd | Uxbridge | A rating |
| MSCI Limited | London | A rating |
| MSI Computer (UK) Ltd | London | A rating |
| MSI Reproductive Choices | London | A rating |
| MSIG Corporate Services (Europe) Limited | London | A rating |
| MSL Cabling Limited | Feltham, Hounslow | A rating |
| MSL Group London Limited | London | A rating |
| MSN Laboratories Europe Limited | Letchworth | A rating |
| MSSL (GB) Limited | Gateshead | A rating |
| MST Europe Limited | London | A rating |
| MSubs Ltd | Plymouth | A rating |
| MTK Wireless Limited " MediaTek" | Cambridge | A rating |