| Royal Mail Group plc | International Distributions Services PLC | miscellaneous services | price-fixing or anti-competitive practices | 2019 | UK-OFCOM | £0 |
| Royal Mail plc | International Distributions Services PLC | miscellaneous services | price-fixing or anti-competitive practices | 2018 | UK-OFCOM | £50,000,000 |
| RWE Generation UK plc | RWE AG | utilities and power generation | energy market violation | 2020 | UK-OFGEM | £4,500,000 |
| Safeway Stores Limited and Strores Group Limited and Safeway Limited | Clayton Dubilier & Rice | private equity (including portfolio companies) | price-fixing or anti-competitive practices | 2011 | UK-OFT | £5,690,000 |
| Sainsbury's Supermarkets Limited and J Sainsbury plc | J Sainsbury PLC | retailing | price-fixing or anti-competitive practices | 2011 | UK-OFT | £11,040,000 |
| Salegroup Limited (The) | | | price-fixing or anti-competitive practices | 2019 | UK-OFCOM | £40,000 |
| Sapien Capital Ltd | | | investor protection violation | 2021 | UK-FCA | £178,000 |
| Sarclad Ltd | | | bribery | 2019 | UK-SFO | £6,553,085 |
| Saxons PS Limited | | | price-fixing or anti-competitive practices | 2017 | UK-CMA | £20,257 |
| Scottish Hydro Electric Power Distribution plc | SSE PLC | utilities and power generation | energy market violation | 2011 | UK-OFGEM | £500,000 |
| Scottish Power | Iberdrola | utilities and power generation | energy market violation | 2023 | UK-OFGEM | £440,000 |
| Scottish Power | Iberdrola | utilities and power generation | energy market violation | 2023 | UK-OFGEM | £1,240,000 |
| Scottish Power Energy Retail Limited | Iberdrola | utilities and power generation | price-fixing or anti-competitive practices | 2016 | UK-CMA | £0 |
| ScottishPower Energy Retail Limited and ScottishPower Generation Limited | Iberdrola | utilities and power generation | energy market violation | 2015 | UK-OFGEM | £2,400,000 |
| Sepura | | | price-fixing or anti-competitive practices | 2022 | UK-OFCOM | £1,500,000 |
| Severn Trent PLC | Severn Trent PLC | utilities and power generation | price-fixing or anti-competitive practices | 2012 | UK-OFWAT | £0 |
| Showmen's Guild of Great Britain | | | price-fixing or anti-competitive practices | 2017 | UK-CMA | £0 |
| Smith and Ouzman Ltd | | | bribery | 2016 | UK-SFO | £2,200,000 |
| Southern Electric Gas Limited | OVO Energy | utilities and power generation | price-fixing or anti-competitive practices | 2016 | UK-CMA | £0 |
| 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 |
| Squibb Group Ltd. | | | price-fixing or anti-competitive practices | 2023 | UK-CMA | £2,000,000 |
| SSE | SSE PLC | utilities and power generation | energy market violation | 2023 | UK-OFGEM | £252,000 |
| SSE | SSE PLC | utilities and power generation | energy market violation | 2015 | UK-OFGEM | £100,000 |
| SSE Energy Services | OVO Energy | utilities and power generation | energy market violation | 2021 | UK-OFGEM | £20,000 |
| SSE Energy Services | OVO Energy | utilities and power generation | consumer protection violation | 2019 | UK-OFGEM | £4,775,705 |
| SSE Energy Services | OVO Energy | utilities and power generation | energy market violation | 2020 | UK-OFGEM | £1,200,000 |
| SSE Energy Services | OVO Energy | utilities and power generation | energy market violation | 2019 | UK-OFGEM | £700,000 |
| SSE Generation Limited | SSE PLC | utilities and power generation | energy market violation | 2020 | UK-OFGEM | £2,060,000 |
| SSE Generation Limited | SSE PLC | utilities and power generation | energy market violation | 2023 | UK-OFGEM | £9,780,000 |
| SSE plc | SSE PLC | utilities and power generation | price-fixing or anti-competitive practices | 2016 | UK-OFGEM | £0 |
| SSE plc | SSE PLC | utilities and power generation | energy market violation | 2015 | UK-OFGEM | £1,750,000 |
| SSE Plc | SSE PLC | utilities and power generation | energy market violation | 2019 | UK-OFGEM | £705,000 |
| SSP Ltd. | | | price-fixing or anti-competitive practices | 2011 | UK-OFT | £0 |
| Stanton Bonna Concrete Limited et al. | | | price-fixing or anti-competitive practices | 2019 | UK-CMA | £7,474,745 |
| Storm Model Management Limited and Storm Models Limited | | | price-fixing or anti-competitive practices | 2016 | UK-CMA | £491,000 |
| Sulion | | | price-fixing or anti-competitive practices | 2022 | UK-PSR | £572 |
| Sweett Group PLC | | | bribery | 2016 | UK-SFO | £2,250,000 |
| Symbio Energy Limited | | | energy market violation | 2021 | UK-OFGEM | £100,000 |
| Symbio Energy Limited | | | consumer protection violation | 2021 | UK-OFGEM | £0 |
| Symbio Energy Limited | | | energy market violation | 2020 | UK-OFGEM | £506,308 |
| T. E. Scudder Ltd | | | price-fixing or anti-competitive practices | 2023 | UK-CMA | £8,256,264 |
| Tarmac | CRH PLC | building materials | price-fixing or anti-competitive practices | 2022 | UK-CMA | £0 |
| Tesco | Tesco PLC | retailing | Groceries Supply Code of Conduct violation | 2016 | UK-GCA | £0 |
| Tesco plc | Tesco PLC | retailing | price-fixing or anti-competitive practices | 2020 | UK-CMA | £0 |
| Tesco Stores Limited and Tesco Holdings Limited and Tesco plc | Tesco PLC | retailing | price-fixing or anti-competitive practices | 2013 | UK-OFT | £6,500,000 |
| Thames Water | Thames Water Utilities Ltd. | utilities and power generation | price-fixing or anti-competitive practices | 2022 | UK-OFWAT | £0 |
| The Association of Model Agents Limited | | | price-fixing or anti-competitive practices | 2016 | UK-CMA | £2,500 |
| 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 |
| 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 |
| The Romans Group (UK) Limited and Romans 1 Limited | | | price-fixing or anti-competitive practices | 2019 | UK-CMA | £0 |
| The Royal Bank of Scotland plc | NatWest Group PLC | financial services | foreign exchange market manipulation | 2014 | UK-FCA | £217,000,000 |
| The Royal Bank of Scotland plc | NatWest Group PLC | financial services | interest rate benchmark manipulation | 2013 | UK-FSA | £87,500,000 |
| ThirdWay Interiors Ltd. and The ThirdWay Group | | | price-fixing or anti-competitive practices | 2019 | UK-CMA | £1,780,703 |
| Thomas Armstrong (Timber) Ltd. and Thomas Armstrong (Holdings) Limited | | | price-fixing or anti-competitive practices | 2017 | UK-CMA | £1,509,000 |
| Thomas Armstrong (Timber) Ltd. and Thomas Armstrong (Holdings) Limited | | | price-fixing or anti-competitive practices | 2017 | UK-CMA | £684,000 |
| Thomas Gunn Navigation Systems Ltd | | | bribery | 2012 | UK-COPFS | £138,000 |
| Three Counties Estate Agents Limited | | | price-fixing or anti-competitive practices | 2015 | UK-CMA | £90 |
| Tiofarma Beheer B.V. and Tiofarma B.V. | | | price-fixing or anti-competitive practices | 2020 | UK-CMA | £186,442 |
| Trinity Mirror Southern Ltd. and Trinity Mirror plc | | | price-fixing or anti-competitive practices | 2015 | UK-CMA | £91,257 |
| Trod Limited | | | price-fixing or anti-competitive practices | 2016 | UK-CMA | £163,371 |
| Turner Topco Ltd. and ATG Media Holdings Ltd. and ATG Media Ltd. and Metropress Ltd. | | | price-fixing or anti-competitive practices | 2017 | UK-CMA | £0 |
| Two Financial Services Limited | | | consumer protection violation | 2021 | UK-FCA | £0 |
| UBS AG | UBS | financial services | foreign exchange market manipulation | 2014 | UK-FCA | £233,814,000 |
| UBS AG | UBS | financial services | interest rate benchmark manipulation | 2012 | UK-FSA | £160,000,000 |
| UK Asbestos Training Association | | | price-fixing or anti-competitive practices | 2013 | UK-OFT | £0 |
| UK Capacity Reserve | | | energy market violation | 2015 | UK-OFGEM | £0 |
| Ultra Finishing Limited | | | price-fixing or anti-competitive practices | 2016 | UK-CMA | £786,668 |
| URE Energy Limited | | | energy market violation | 2019 | UK-OFGEM | £209,013 |
| Utilita | | | consumer protection violation | 2017 | UK-OFGEM | £3,580,000 |
| Utilita Energy | | | energy market violation | 2019 | UK-OFGEM | £175,000 |
| Utility Warehouse | Telecom Plus PLC | utilities and power generation | consumer protection violation | 2021 | UK-OFGEM | £1,500,000 |
| Virgin Money UK plc | Virgin Money UK PLC | financial services | banking violation | 2021 | UK-CMA | £0 |
| Viva Model Management London Limited and Viva Model Management Sarl | | | price-fixing or anti-competitive practices | 2016 | UK-CMA | £245,000 |
| Vp plc | | | price-fixing or anti-competitive practices | 2020 | UK-CMA | £11,235,660 |
| Waitrose | John Lewis Partnership | retailing | price-fixing or anti-competitive practices | 2022 | UK-CMA | £0 |
| Wales and West Utilities Limited | CK Hutchison Holdings | diversified | energy market violation | 2012 | UK-OFGEM | £375,000 |
| Waterfords (Estate Agents) Limited | | | price-fixing or anti-competitive practices | 2015 | UK-CMA | £46,186 |
| Waymade Plc | | | price-fixing or anti-competitive practices | 2021 | UK-CMA | £2,500,000 |
| Weir Group Plc | Weir Group PLC | industrial equipment | bribery | 2010 | UK-COPFS | £16,900,000 |
| West Coast Property Services (UK) Limited | | | price-fixing or anti-competitive practices | 2017 | UK-CMA | £55,624 |
| Whoop Energy | | | energy market violation | 2021 | UK-OFGEM | £56,306 |
| Willis Limited | Willis Towers Watson | financial services | bribery | 2011 | UK-FSA | £6,895,000 |
| Wm Morrison Supermarkets Limited | Clayton Dubilier & Rice | private equity (including portfolio companies) | price-fixing or anti-competitive practices | 2023 | UK-CMA | £0 |
| Yamaha Music Europe GmbH | | | price-fixing or anti-competitive practices | 2020 | UK-CMA | £0 |
| Zurich Insurance plc | Zurich Insurance | financial services | price-fixing or anti-competitive practices | 2011 | UK-OFT | £0 |
