| HH Saudi Research & Marketing (UK) Ltd | London | A rating |
| HHV Ltd | West Sussex | A rating |
| Hi Bob (UK) Limited | London | A rating |
| Hi Tech Solutions and Consulting Ltd | Suffolk | A rating |
| Hi-Wire Limited | Castleford | A rating |
| Hiberly Ltd | Cambridge | A rating |
| Hibernian Football Club Limited | Edinburgh | A rating |
| HID Corporation Limited | CARDIFF | A rating |
| HiFX Europe Limited | Bracknell | A rating |
| Highbrook Investors UK Limited | London | A rating |
| Higher Concept Software Limited | Reading | A rating |
| Higher Health U.K. Limited | Preston | A rating |
| Highland Europe UK Management Limited | London | A rating |
| Highly Marelli UK Limited | Sunderland | A rating |
| HighRadius UK Limited | London | A rating |
| Highroads NI Limited | Belfast | A rating |
| Highspot UK Limited | London | A rating |
| Highview Enterprises Ltd | London | A rating |
| Hiho Metal Europe Ltd | London | A rating |
| Hikma Pharmaceuticals PLC | London | A rating |
| Hikvision UK Limited | Uxbridge | A rating |
| Hilco Appraisal Limited | London | A rating |
| Hill & Smith Holdings PLC | Solihull | A rating |
| HILL'S PET NUTRITION LTD | Woking | A rating |
| Hills Numberplates Limited | Birmingham | A rating |
| Hillsong Church London | London | A rating |
| Hillwood Investment Properties International Ltd | London | A rating |
| Hilti (Gt. Britain) Limited | Manchester | A rating |
| Hilton UK Hotels Limited | Watford | A rating |
| HINDUJA AUTOMOTIVE LIMITED | LONDON | A rating |
| Hinduja Global Solutions UK Limited (HGS UK Ltd) | Preston | A rating |
| HINDUJA TECH LIMITED (UK Branch) | London | A rating |
| Hindustan Aeronautics Limited, Liaison Office | London | A rating |
| Hinen UK Limited | Birmingham | A rating |
| Hines Europe Real Estate Investments Limited | London | A rating |
| Hiperpool Ltd | London | A rating |
| Hiram Lodge Enterprises LTD | London | A rating |
| HireVue UK Ltd | Oxford | A rating |
| Hirose Financial UK Ltd. | London | A rating |
| HIS - MIKI TRAVEL UK LIMITED | London | A rating |
| Hisamitsu UK Ltd. | London | A rating |
| HISCOX UNDERWRITING GROUP SERVICES LIMITED | London | A rating |
| Hisense UK Limited | Leeds | A rating |
| HiSkySat Ltd | Harwell | A rating |
| Hispania Global UW Ltd | London | A rating |
| Hitachi Capital (UK) PLC | Staines-upon-Thames | A rating |
| Hitachi Construction Machinery (UK) Limited | Hebburn | A rating |
| Hitachi Digital Services UK Limited | London | A rating |
| HITACHI ENERGY UK LIMITED | Birmingham | A rating |
| Hitachi Europe Ltd | Slough | A rating |
| Hitachi High-Tech Analytical Science Ltd | Abingdon | A rating |
| Hitachi High-Tech Europe GmbH | Warrington | A rating |
| Hitachi Information Control Systems Europe Ltd. | Bradford on Avon | A rating |
| Hitachi Rail Limited | Ashford | A rating |
| Hitachi Solutions Europe Ltd | London | A rating |
| Hitachi Vantara Limited | London | A rating |
| Hitched Limited | London | A rating |
| HitecVision Advisory UK Limited | London | A rating |
| HiTek Power Limited | Littlehampton | A rating |
| HITEX TRAFFIC SAFETY LIMITED | Cheshire | A rating |
| Hive Autonomy UK Limited | London | A rating |
| Hiya Communications UK Limited | London | A rating |
| HJS Emission Technology Limited | Swindon | A rating |
| HKA Global Ltd. | Warrington | A rating |
| HKS ARCHITECTS LIMITED | London | A rating |
| HLHP Oriental Food Limited T/A Happy Lamb Hot Pot Restaurant | London | A rating |
| HLMAD Ltd | Sheffield | A rating |
| HLW International Ltd | London | A rating |
| HME Clear-Com Limited | Cambridge | A rating |
| HMM (Europe) Ltd. | London | A rating |
| HMY UK INNOVATION IN RETAIL LTD | Newcastle Upon Tyne | A rating |
| HNRY (UK) Limited | London | A rating |
| Hobart UK , a division of ITW Ltd | Peterborough | A rating |
| Hochiki Europe UK Ltd | Gillingham | A rating |
| Hochtief (UK) Construction Limited | Swindon | A rating |
| HOCHTIEF PPP SOLUTIONS (UK) LIMITED | SWINDON | A rating |
| Hogan Lovells International LLP | London | A rating |
| HOK International Limited | London | A rating |
| Holborn Shared Ventures Ltd | London | A rating |
| Holcim UK Limited | Markfield | A rating |
| HOLDING BAM UK LTD | London | A rating |
| Holland & Barrett Retail Limited | Nuneaton | A rating |
| Holland & Knight (UK) LLP | London | A rating |
| Hollingsworth and Vose Company Limited | Cheltenham | A rating |
| Hollister Europe Limited | Winnersh | A rating |
| Hollway Advisory Services UK Ltd | Borehamwood | A rating |
| Hollyport Capital LLP | London | A rating |
| Holman Fenwick Willan LLP | London | A rating |
| Holman Fleet Limited | Chippenham | A rating |
| Holmen Board and Paper Limited | Cumbria | A rating |
| Hologic Ltd | Manchester | A rating |
| Holt Lloyd International Ltd | Manchester | A rating |
| Holtec Britain Limited | Suffolk | A rating |
| Holzweiler UK Limited | London | A rating |
| HONDA MOTOR EUROPE LTD | Bracknell | A rating |
| Honda R & D Europe (UK) Ltd | Reading | A rating |
| Honeywell Aerospace UK Co Limited | Redditch | A rating |
| Honeywell Limited | Bracknell | A rating |
| HONOR TECHNOLOGIES (UK) CO., LTD | London | A rating |
| Hoonar Tekwurks Consulting Limited | London | A rating |
| Hootsuite Media UK Ltd | London | A rating |
| Hooyu Ltd | London | A rating |
| Hopkins Architects Ltd | London | A rating |
| HOPPER UK INC. LTD | London | A rating |
| Hopscotch Network UK | London | A rating |
| Hoptroff London Ltd | London | A rating |
| Hori (U.K.) Limited | London | A rating |
| HORIBA MIRA Ltd | Nuneaton | A rating |
| HORIBA Test Automation Limited | Worcester | A rating |
| HORIBA UK Limited | Northampton | A rating |
| Horizon Asset LLP | London | A rating |
| Horizon Industries International Ltd | London | A rating |
| Horizontal Drilling International UK Branch | Newcastle Upon Tyne | A rating |
| Horse Powertrain Limited | London | A rating |
| Horstman Defence Systems Limited | Bath | A rating |
| Hoshizaki Europe Limited | Telford | A rating |
| HOTEL CO 51 UK LIMITED | Hounslow | A rating |
| Hotel Reservation Service Limited | Cambridge | A rating |
| Hotel Technology Management (htm) ltd | Milton Keynes | A rating |
| HOTPOINT UK APPLIANCES LIMITED | Peterborough | A rating |
| Hottinger Bruel & Kjaer UK Ltd | Rotherham | A rating |
| HOULIHAN LOKEY UK LIMITED | London | A rating |
| Household Design Ltd | London | A rating |
| Houthoff London BV | London | A rating |
| Houzz UK Ltd | London | A rating |
| Howden Group Holdings Limited | LONDON | A rating |
| Howden Group Ltd | Renfrew | A rating |
| Howe Robinson Partners (UK) Limited | London | A rating |
| Howmet Ltd | Exeter | A rating |
| HP Inc UK Limited | Reading | A rating |
| HPC London Branch | London | A rating |
| HPREF II UK HOTEL MANAGEMENT LIMITED | Glasgow | A rating |
| HPS Investment Partners (UK) LLP | London | A rating |
| HR Wallingford Group Limited | Wallingford | A rating |
| HRS Investments Limited | Watford | A rating |
| HRT Research UK Ltd | London | A rating |
| HRTSVC Ltd | London | A rating |
| HSB Engineering Insurance Ltd | Manchester | A rating |
| HSBC Holdings plc | London | A (Premium) |
| HSF LONDON LTD | London | A rating |
| Httpool Holdings UK Limited | Manchester | A rating |
| Hua Nan Commercial Bank Ltd | London | A rating |
| Huawei Technologies (UK) Co., Ltd | Reading | A rating |
| Huawei Technologies Research & Development (UK) Limited | Cambridge | A rating |
| Huber Parking UK Limited | Langley | A rating |
| HUBER+SUHNER Polatis | Cambridge | A rating |
| Hubexo UK Limited | Newcastle Upon Tyne | A rating |
| HubSpot UK Holdings Limited | London | A rating |
| Hudl UK Limited | London | A rating |
| Hudson Advisors UK Ltd. | London | A rating |
| Hudson River Trading Europe Ltd. | London | A rating |
| Hudson RPO Limited | Salford | A rating |
| Huge UK Limited | London | A rating |
| HUGHES SYSTIQUE PRIVATE LTD | High Wycombe | A rating |
| HUGO BOSS UK Ltd | London | A rating |
| Huhtamaki BCP Limited | Blackburn | A rating |
| Hull City Tigers Limited | Hull | A rating |
| Hult International Business School | Bloomsbury | A rating |
| Hult Recruiting Services | London | A rating |
| Human Capital Search Ltd | London | A rating |
| Human Made Machine Limited | London | A rating |
| Human Rights Watch, London Branch | London | A rating |
| Human Security UK Limited | Altrincham | A rating |
| Humax Electronics Co Ltd | New Malden | A rating |
| Hummingbird UK Partners Limited | London | A rating |
| HungryPanda Ltd | London | A rating |
| Hunter Boot Ltd | London | A rating |
| Hunter Douglas UK Retail Limited | Colwick | A rating |
| Hunting Energy Holdings Limited | London | A rating |
| Huntleigh Healthcare Limited | Cardiff | A rating |
| Hunton Andrews Kurth (UK) LLP | London | A rating |
| Huntsman Surface Sciences UK Limited | Cambridge | A rating |
| Huron Consulting Services UK Ltd | London | A rating |
| Hurtigruten UK Limited | London | A rating |
| Husco International Partners LLP | Runcorn | A rating |
| Husqvarna UK Ltd | Durham | A rating |
| Hutchison 3G UK Limited | Reading | A rating |
| Hutchison Property Group (UK) Limited | Battersea | A rating |
| Hutchison Whampoa (Europe) Limited | London | A rating |
| HVL PHARMA UK LTD | Haverhill | A rating |
| HX Group Ltd | London | A rating |
| Hydrafacial UK Limited | Rugby | A rating |
| HydraForce Hydraulics Limited | Birmingham | A rating |
| Hydram Engineering Limited | Chilton | A rating |
| Hydro Aluminium UK Limited | Alfreton | A rating |
| Hydro International Limited | Clevedon | A rating |
| Hyland UK Operations Limited | Maidenhead | A rating |
| Hylink (UK) Digital Solution Limited | London | A rating |
| Hynamics UK Limited | London | A rating |
| Hynedale Ltd t/a Noble Sleek | Essex | A rating |
| HYOSUNG TNS UK BRANCH | Weybridge | A rating |
| HYOSUNG UK LIMITED | New Malden | A rating |
| Hyperion Robotics UK Ltd | Scunthorpe | A rating |
| HYPEROPTIC LTD | London | A rating |
| Hyperscience Europe Ltd | Altrincham | A rating |
| Hyspec Engineering Limited | Stewarton | A rating |
| Hyster-Yale Group | Irvine | A rating |
| Hytera Communications (UK) Co., Ltd | Slough | A rating |
| Hytronik International LTD | Manchester | A rating |
| Hyundai Capital UK Limited | Reigate | A rating |