| British Gas | Centrica | utilities and power generation | energy market violation | 2023 | UK-OFGEM | £3,370,000 |
| Robert Wiseman & Sons Limited and Robert Wiseman Dairies plc | | | price-fixing or anti-competitive practices | 2011 | UK-OFT | £3,200,000 |
| National Grid | National Grid | utilities and power generation | energy market violation | 2016 | UK-OFGEM | £3,000,000 |
| Airline Services Limited | | | bribery | 2020 | UK-SFO | £2,979,685 |
| British Telecommunications plc | BT | telecommunications | price-fixing or anti-competitive practices | 2013 | UK-OFCOM | £2,896,800 |
| Auden Mckenzie (Pharma Division) Ltd. and Accord-UK Ltd. | Intas Pharmaceuticals Ltd. | pharmaceuticals | price-fixing or anti-competitive practices | 2020 | UK-CMA | £2,882,238 |
| CPL Distribution Limited and CPL Industries Holdings Limited | | | price-fixing or anti-competitive practices | 2018 | UK-CMA | £2,816,514 |
| The National Lighting Co. Ltd. and Saxby Lighting Ltd. and Endon Lighting Ltd. and Poole Lighting Ltd. | | | price-fixing or anti-competitive practices | 2017 | UK-CMA | £2,763,000 |
| Nabuh Energy Ltd | | | energy market violation | 2020 | UK-OFGEM | £2,683,631 |
| Copart, Inc. and CPRT LLP and Copart UK Ltd. | Copart Inc. | information services | price-fixing or anti-competitive practices | 2023 | UK-CMA | £2,500,000 |
| Waymade Plc | | | price-fixing or anti-competitive practices | 2021 | UK-CMA | £2,500,000 |
| npower Direct Ltd. and npower Ltd. and npower Northern Ltd. and npower Yorkshire Ltd. | E.ON | utilities and power generation | energy market violation | 2018 | UK-OFGEM | £2,400,000 |
| ScottishPower Energy Retail Limited and ScottishPower Generation Limited | Iberdrola | utilities and power generation | energy market violation | 2015 | UK-OFGEM | £2,400,000 |
| Brown and Mason Group Ltd | | | price-fixing or anti-competitive practices | 2023 | UK-CMA | £2,400,000 |
| OVO | | | energy market violation | 2023 | UK-OFGEM | £2,390,000 |
| ITW Limited | Illinois Tool Works | industrial equipment | price-fixing or anti-competitive practices | 2016 | UK-CMA | £2,298,820 |
| Sweett Group PLC | | | bribery | 2016 | UK-SFO | £2,250,000 |
| B Limited | | | bribery | 2016 | UK-COPFS | £2,200,000 |
| Smith and Ouzman Ltd | | | bribery | 2016 | UK-SFO | £2,200,000 |
| Engie Global Markets | Engie | utilities and power generation | energy market manipulation | 2019 | UK-OFGEM | £2,128,236 |
| Guralp Systems Ltd | | | bribery | 2019 | UK-SFO | £2,069,861 |
| SSE Generation Limited | SSE PLC | utilities and power generation | energy market violation | 2020 | UK-OFGEM | £2,060,000 |
| Franklin Hodge Industries Ltd. and Carter Thermal Industries Ltd. | | | price-fixing or anti-competitive practices | 2016 | UK-CMA | £2,015,135 |
| Squibb Group Ltd. | | | price-fixing or anti-competitive practices | 2023 | UK-CMA | £2,000,000 |
| Cantillon Ltd and Cantillon Holdings Ltd | | | price-fixing or anti-competitive practices | 2023 | UK-CMA | £1,920,000 |
| Oxford Publishing Limited | | | bribery | 2012 | UK-SFO | £1,895,435 |
| Focus Pharmaceuticals Limited and Mercury Pharma Group Ltd. and Cinven Partners LLP et al. | Nordic Capital | private equity (including portfolio companies) | price-fixing or anti-competitive practices | 2022 | UK-CMA | £1,843,380 |
| Bulb | | | energy market violation | 2023 | UK-OFGEM | £1,830,000 |
| ThirdWay Interiors Ltd. and The ThirdWay Group | | | price-fixing or anti-competitive practices | 2019 | UK-CMA | £1,780,703 |
| Bulb | | | consumer protection violation | 2020 | UK-OFGEM | £1,757,837 |
| SSE plc | SSE PLC | utilities and power generation | energy market violation | 2015 | UK-OFGEM | £1,750,000 |
| British Gas | Centrica | utilities and power generation | consumer protection violation | 2020 | UK-OFGEM | £1,728,070 |
| E.ON | E.ON | utilities and power generation | energy market violation | 2023 | UK-OFGEM | £1,720,000 |
| British Gas/ Centrica | Centrica | utilities and power generation | consumer protection violation | 2021 | UK-OFGEM | £1,660,272 |
| Lactalis McLelland Limited | Lactalis | food products | price-fixing or anti-competitive practices | 2011 | UK-OFT | £1,660,000 |
| Heathrow Airport Ltd. and Heathrow Airport Holdings Ltd. | Heathrow Airport Holdings | miscellaneous services | price-fixing or anti-competitive practices | 2018 | UK-CMA | £1,600,000 |
| Actavis UK Ltd. | Intas Pharmaceuticals Ltd. | pharmaceuticals | price-fixing or anti-competitive practices | 2016 | UK-CMA | £1,542,860 |
| Associated Lead Mills Limited and Royston Sheet Lead Limited and International Metal Industries Limited | | | price-fixing or anti-competitive practices | 2020 | UK-CMA | £1,510,228 |
| Thomas Armstrong (Timber) Ltd. and Thomas Armstrong (Holdings) Limited | | | price-fixing or anti-competitive practices | 2017 | UK-CMA | £1,509,000 |
| Korg (UK) Ltd. and Korg Inc. | | | price-fixing or anti-competitive practices | 2020 | UK-CMA | £1,504,707 |
| National Grid Electricity System Operator Limited | National Grid | utilities and power generation | energy market violation | 2021 | UK-OFGEM | £1,500,000 |
| iSupply | | | consumer protection violation | 2020 | UK-OFGEM | £1,500,000 |
| Eastern Power Networks plc and South Eastern Power Networks plc | | | energy market violation | 2020 | UK-OFGEM | £1,500,000 |
| Utility Warehouse | Telecom Plus PLC | utilities and power generation | consumer protection violation | 2021 | UK-OFGEM | £1,500,000 |
| Meta Platforms, Inc. and Tabby Acquisition Sub Inc. and Facebook UK Ltd. | Meta Platforms Inc. | information technology | price-fixing or anti-competitive practices | 2022 | UK-CMA | £1,500,000 |
| Sepura | | | price-fixing or anti-competitive practices | 2022 | UK-OFCOM | £1,500,000 |
| Mercedes-Benz UK Limited and Daimler UK Limited and Daimler AG | Mercedes-Benz Group | motor vehicles | price-fixing or anti-competitive practices | 2013 | UK-OFT | £1,492,646 |
| JD Sports Fashion Plc | JD Sports Fashion | retailing | price-fixing or anti-competitive practices | 2022 | UK-CMA | £1,485,000 |
| Ping Europe Limited | | | price-fixing or anti-competitive practices | 2017 | UK-CMA | £1,450,000 |
| DSM Demolition Ltd et al. | | | price-fixing or anti-competitive practices | 2023 | UK-CMA | £1,400,000 |
| The Cheese Company Ltd. and Waterford Foods International Ltd. and Glanbia Investments (UK) Ltd. and Glanbia (UK) Ltd. | | | price-fixing or anti-competitive practices | 2011 | UK-OFT | £1,260,000 |
| Scottish Power | Iberdrola | utilities and power generation | energy market violation | 2023 | UK-OFGEM | £1,240,000 |
| Lexon (UK) Limited | Bestway Healthcare | healthcare services | price-fixing or anti-competitive practices | 2021 | UK-CMA | £1,220,383 |
| Spire Healthcare Ltd. and Spire Healthcare Group plc | Spire Healthcare PLC | healthcare services | price-fixing or anti-competitive practices | 2020 | UK-CMA | £1,200,000 |
| British Telecommunications plc | BT | telecommunications | consumer protection violation | 2014 | UK-OFCOM | £1,200,000 |
| SSE Energy Services | OVO Energy | utilities and power generation | energy market violation | 2020 | UK-OFGEM | £1,200,000 |
| Berendsen Cleanroom Services Ltd. fka Micronclean (Newbury) Ltd. and Berendsen plc | | | price-fixing or anti-competitive practices | 2017 | UK-CMA | £1,197,956 |
| Medreich plc and Medreich Ltd | Meiji Group | food products | price-fixing or anti-competitive practices | 2022 | UK-CMA | £1,167,554 |
| Loop Interiors London LLP and Loop Interiors Ltd. | | | price-fixing or anti-competitive practices | 2019 | UK-CMA | £1,090,816 |
| British Gas Trading Limited | Centrica | utilities and power generation | energy market violation | 2011 | UK-OFGEM | £1,000,000 |
| Focus Pharmaceuticals Ltd. and Focus Pharma Holdings Ltd. and Mercury Pharma Group Ltd. | Nordic Capital | private equity (including portfolio companies) | price-fixing or anti-competitive practices | 2022 | UK-CMA | £921,357 |
| Prepaid Financial Services Limited | | | price-fixing or anti-competitive practices | 2022 | UK-PSR | £916,746 |
| Leicester City Football Club Limited | | | price-fixing or anti-competitive practices | 2023 | UK-CMA | £880,000 |
| FH Bertling Ltd | | | bribery | 2019 | UK-SFO | £850,000 |
| Ultra Finishing Limited | | | price-fixing or anti-competitive practices | 2016 | UK-CMA | £786,668 |
| Advanced Payment Solutions | | | price-fixing or anti-competitive practices | 2022 | UK-PSR | £755,419 |
| Hudson Energy Supply UK Ltd | | | consumer protection violation | 2020 | UK-OFGEM | £750,000 |
| SSE Plc | SSE PLC | utilities and power generation | energy market violation | 2019 | UK-OFGEM | £705,000 |
| SSE Energy Services | OVO Energy | utilities and power generation | energy market violation | 2019 | UK-OFGEM | £700,000 |
| Thomas Armstrong (Timber) Ltd. and Thomas Armstrong (Holdings) Limited | | | price-fixing or anti-competitive practices | 2017 | UK-CMA | £684,000 |
| E.ON | E.ON | utilities and power generation | consumer protection violation | 2021 | UK-OFGEM | £682,351 |
| GNERGYLimited | | | energy market violation | 2019 | UK-OFGEM | £673,876 |
| Ciceley Commercials Limited and Ciceley Limited | | | price-fixing or anti-competitive practices | 2013 | UK-OFT | £659,675 |
| E (Gas and Electricity) Ltd | | | price-fixing or anti-competitive practices | 2019 | UK-OFGEM | £650,000 |
| Martin Brokers (UK) Ltd | | | interest rate benchmark manipulation | 2014 | UK-FCA | £630,000 |
| Fuel Express Ltd. and Fuel Express (Bagnalls) Ltd. and Carbo (UK) Ltd. and G.N. Grosvenor Ltd. | | | price-fixing or anti-competitive practices | 2018 | UK-CMA | £627,867 |
| Hoffman Thornwood Ltd. and Consolidated Timer Holdings Ltd. | | | price-fixing or anti-competitive practices | 2017 | UK-CMA | £625,000 |
| Lexon (UK) Limited and Lexon UK Holdings Limited | Bestway Healthcare | healthcare services | price-fixing or anti-competitive practices | 2022 | UK-CMA | £593,780 |
| Galglass Ltd. Irish Industrial Tanks Ltd. and Kernoff Ltd. | | | price-fixing or anti-competitive practices | 2016 | UK-CMA | £587,926 |
| Hamptons Estates Ltd. and Countrywide plc and Countrywide Group plc | | | price-fixing or anti-competitive practices | 2015 | UK-CMA | £582,455 |
| Focus Pharmaceuticals Limited and Focus Pharma Holdings Limited | Nordic Capital | private equity (including portfolio companies) | price-fixing or anti-competitive practices | 2022 | UK-CMA | £549,343 |
| Delta Gas and Power Limited | | | consumer protection violation | 2022 | UK-OFGEM | £530,809 |
| iSupply Energy | | | consumer protection violation | 2020 | UK-OFGEM | £520,539 |
| Micronclean Ltd. fka Fenland Laundries Ltd. | | | price-fixing or anti-competitive practices | 2017 | UK-CMA | £510,118 |
| Symbio Energy Limited | | | energy market violation | 2020 | UK-OFGEM | £506,308 |
| British Gas | Centrica | utilities and power generation | energy market violation | 2015 | UK-OFGEM | £500,000 |
| Scottish Hydro Electric Power Distribution plc | SSE PLC | utilities and power generation | energy market violation | 2011 | UK-OFGEM | £500,000 |
| Storm Model Management Limited and Storm Models Limited | | | price-fixing or anti-competitive practices | 2016 | UK-CMA | £491,000 |
| Hudson Energy Supply UK Ltd | | | consumer protection violation | 2018 | UK-OFGEM | £477,039 |
| Elite Sports Group Limited and Elite Corporation Limited | | | price-fixing or anti-competitive practices | 2022 | UK-CMA | £459,000 |
| GDF Suez/IPM | Engie | utilities and power generation | energy market violation | 2015 | UK-OFGEM | £450,000 |
| Scottish Power | Iberdrola | utilities and power generation | energy market violation | 2023 | UK-OFGEM | £440,000 |
| Clifford Devlin Ltd | | | price-fixing or anti-competitive practices | 2023 | UK-CMA | £423,615 |
| Central Networks East plc and Central Networks West plc | | | energy market violation | 2011 | UK-OFGEM | £400,000 |
| Footasylum | | | price-fixing or anti-competitive practices | 2022 | UK-CMA | £400,000 |
| Alsford Page & Gems Limited | | | consumer protection violation | 2021 | UK-FCA | £399,902 |
| Models One Ltd. and One Worldwide Ltd. and Models 1 New Co Ltd. | | | price-fixing or anti-competitive practices | 2016 | UK-CMA | £394,000 |
| Consultant Eye Surgeons Partnership (CESP) Ltd. | | | price-fixing or anti-competitive practices | 2015 | UK-CMA | £382,500 |
| Wales and West Utilities Limited | CK Hutchison Holdings | diversified | energy market violation | 2012 | UK-OFGEM | £375,000 |
| Hamsard 3149 Ltd. and Quantum Pharmaceutical Ltd. and Total Medication Management System dba Tomms Pharmacy | | | price-fixing or anti-competitive practices | 2014 | UK-OFT | £370,226 |
| Hudson Energy Supply UK Ltd. | | | consumer protection violation | 2019 | UK-OFGEM | £350,000 |
