| Virgin Holidays Ltd and Virgin Atlantic Airways Ltd. and Virgin Atlantic Ltd. | Virgin Group | diversified | consumer protection violation | 2020 | UK-CMA | £203,000,000 |
| Southern Water | Macquarie | financial services | water services violation | 2019 | UK-OFWAT | £126,000,000 |
| Thames Water Utilities Limited | Thames Water Utilities Ltd. | utilities and power generation | water services violation | 2018 | UK-OFWAT | £120,000,000 |
| Lloyds Bank plc and Bank of Scotland plc and Black Horse Limited | Lloyds Banking Group | financial services | insurance violation | 2015 | UK-FCA | £117,430,600 |
| Yorkshire Water | Kelda Group | utilities and power generation | water services violation | 2022 | UK-OFWAT | £100,000,000 |
| Lloyds Bank General Insurance Limited | Lloyds Banking Group | financial services | insurance violation | 2021 | UK-FCA | £90,688,400 |
| Welsh Water | Dwr Cymru Cyfyngedig (Welsh Water) | utilities and power generation | water services violation | 2024 | UK-OFWAT | £40,000,000 |
| Welsh Water | Dwr Cymru Cyfyngedig (Welsh Water) | utilities and power generation | water services violation | 2024 | UK-OFWAT | £39,400,000 |
| HomeServe Membership Limited | Brookfield Corporation | diversified | insurance violation | 2014 | UK-FCA | £30,647,400 |
| The Carphone Warehouse Limited | Currys PLC | retailing | insurance violation | 2019 | UK-FCA | £29,107,600 |
| Barclays Bank UK PLC and Barclays Bank PLC and Clydesdale Financial Services Ltd. | Barclays | financial services | consumer protection violation | 2020 | UK-FCA | £26,056,400 |
| npower Limited et al. | E.ON | utilities and power generation | consumer protection violation | 2016 | UK-OFGEM | £26,000,000 |
| Clydesdale Bank PLC | Virgin Money UK PLC | financial services | insurance violation | 2015 | UK-FCA | £20,678,300 |
| British Airways | International Airlines Group | airlines | privacy violation | 2020 | UK-ICO | £20,000,000 |
| Marriott International Inc | Marriott International | hotels | privacy violation | 2020 | UK-ICO | £18,400,000 |
| We Love Holidays Limited | | | consumer protection violation | 2020 | UK-CMA | £18,000,000 |
| ScottishPower Energy Retail Limited | Iberdrola | utilities and power generation | consumer protection violation | 2016 | UK-OFGEM | £18,000,000 |
| Entain Group | Entain PLC | entertainment | gambling industry violation | 2022 | UK-GC | £17,000,000 |
| Western Power Distribution | National Grid | utilities and power generation | consumer protection violation | 2022 | UK-OFGEM | £14,900,000 |
| Vanquis Bank Limited | Vanquis Banking Group | financial services | consumer protection violation | 2018 | UK-FCA | £13,852,000 |
| Caesars Entertainment UK Limited | Silver Point Capital | private equity (including portfolio companies) | gambling industry violation | 2020 | UK-GC | £13,115,000 |
| TikTok Information Technologies UK Limited and TikTok Inc | ByteDance | information technology | privacy violation | 2023 | UK-ICO | £12,700,000 |
| WHG (International) Limited | 888 Holdings PLC | entertainment | gambling industry violation | 2023 | UK-GC | £12,500,000 |
| E.ON Energy Solutions Limited | E.ON | utilities and power generation | consumer protection violation | 2014 | UK-OFGEM | £12,000,001 |
| Betway Limited | | | gambling industry violation | 2020 | UK-GC | £11,618,940 |
| Equifax Ltd | Equifax | miscellaneous services | privacy violation | 2023 | UK-FCA | £11,164,400 |
| Thames Water | Thames Water Utilities Ltd. | utilities and power generation | water services violation | 2021 | UK-OFWAT | £11,000,000 |
| Barclays Bank Plc | Barclays | financial services | consumer protection violation | 2022 | UK-FCA | £10,860,743 |
| Card Protection Plan Limited | | | insurance violation | 2012 | UK-FSA | £10,500,000 |
| SSE Energy Supply Limited and Southern Electric Gas Limited | SSE PLC | utilities and power generation | consumer protection violation | 2013 | UK-OFGEM | £10,500,000 |
| O2 | VMED O2 UK Limited | telecommunications | consumer protection violation | 2021 | UK-OFCOM | £10,500,000 |
| British Gas Trading Limited | Centrica | utilities and power generation | consumer protection violation | 2017 | UK-OFGEM | £9,500,000 |
| 888 UK Limited | 888 Holdings PLC | entertainment | gambling industry violation | 2022 | UK-GC | £9,409,756 |
| Clydesdale Bank PLC | Virgin Money UK PLC | financial services | consumer protection violation | 2013 | UK-FCA | £8,904,000 |
| Ovo Gas Limited and Ovo Electricity Limited | OVO Energy | utilities and power generation | consumer protection violation | 2020 | UK-OFGEM | £8,876,500 |
| Scottish Power Energy Retail Limited | Iberdrola | utilities and power generation | consumer protection violation | 2013 | UK-OFGEM | £8,500,001 |
| Barclays | Barclays | financial services | consumer protection violation | 2022 | UK-PSR | £8,400,000 |
| Stonebridge International Insurance Limited | | | insurance violation | 2014 | UK-FCA | £8,373,600 |
| 888 UK Limited | 888 Holdings PLC | entertainment | gambling industry violation | 2017 | UK-GC | £7,824,023 |
| E.ON Energy Solutions Limited | E.ON | utilities and power generation | consumer protection violation | 2015 | UK-OFGEM | £7,750,000 |
| Swinton Group Limited | | | insurance violation | 2013 | UK-FCA | £7,380,400 |
| Daub Alderney Limited | | | gambling industry violation | 2018 | UK-GC | £7,100,000 |
| Truly Holdings Ltd | | | consumer protection violation | 2021 | UK-CMA | £7,000,000 |
| Bravonext SA dba Lastminute.com | | | consumer protection violation | 2020 | UK-CMA | £7,000,000 |
| Virgin Media | VMED O2 UK Limited | telecommunications | consumer protection violation | 2018 | UK-OFCOM | £7,000,000 |
| Thames Water Utilities Limited | Thames Water Utilities Ltd. | utilities and power generation | water services violation | 2014 | UK-OFWAT | £7,000,000 |
| EE Limited | BT | telecommunications | consumer protection violation | 2018 | UK-OFCOM | £6,300,000 |
| WHG (International) Limited | 888 Holdings PLC | entertainment | gambling industry violation | 2018 | UK-GC | £6,276,600 |
| In Touch Games Ltd. | | | gambling industry violation | 2023 | UK-GC | £6,133,310 |
| Gamesys Operations Limited | Bally's Corporation | entertainment | consumer protection violation | 2024 | UK-GC | £6,071,292 |
| Casumo Services Limited | | | gambling industry violation | 2021 | UK-GC | £6,005,000 |
| Ladbrokes Coral Group | Entain PLC | entertainment | gambling industry violation | 2019 | UK-GC | £5,900,000 |
| Daub Alderney Limited | | | gambling industry violation | 2021 | UK-GC | £5,850,000 |
| Casumo Services Limited | | | gambling industry violation | 2018 | UK-GC | £5,850,000 |
| Royal Mail | International Distributions Services PLC | miscellaneous services | consumer protection violation | 2023 | UK-OFCOM | £5,600,000 |
| E.On Next | E.ON | utilities and power generation | consumer protection violation | 2023 | UK-OFGEM | £5,500,000 |
| Liberty Mutual Insurance Europe SE | Liberty Mutual Insurance | financial services | insurance violation | 2018 | UK-FCA | £5,280,800 |
| Govia Thameslink Railway Ltd | Go-Ahead Group PLC | miscellaneous services | consumer protection violation | 2019 | UK-ORR | £5,000,000 |
| E.On Next Energy Ltd | E.ON | utilities and power generation | utility violation | 2023 | UK-OFGEM | £5,000,000 |
| EDF Energy Customers plc | EDF-Electricite de France | utilities and power generation | consumer protection violation | 2012 | UK-OFGEM | £4,500,001 |
| Interserve Group Limited | Interserve Group Limited | business services | privacy violation | 2022 | UK-ICO | £4,400,000 |
| Lloyds Banking Group | Lloyds Banking Group | financial services | consumer protection violation | 2013 | UK-FCA | £4,315,000 |
| National Grid Gas plc | National Gas Transmission PLC | utilities and power generation | consumer protection violation | 2012 | UK-OFGEM | £4,300,000 |
| Bank of Scotland | Lloyds Banking Group | financial services | consumer protection violation | 2012 | UK-FSA | £4,200,000 |
| 32Red Limited | | | gambling industry violation | 2023 | UK-GC | £4,195,655 |
| Bluefin Insurance Services Limited | | | insurance violation | 2017 | UK-FCA | £4,023,800 |
| British Gas Trading Limited | Centrica | utilities and power generation | consumer protection violation | 2014 | UK-OFGEM | £4,003,857 |
| Genesis Global Limited | | | gambling industry violation | 2022 | UK-GC | £3,769,920 |
| Vodafone Limited | Vodafone Group PLC | telecommunications | consumer protection violation | 2016 | UK-OFCOM | £3,700,000 |
| Mr Green Limited | 888 Holdings PLC | entertainment | gambling industry violation | 2023 | UK-GC | £3,700,000 |
| npower Northern Limited-Gas and npower Northern Supply Limited-Electricity | E.ON | utilities and power generation | consumer protection violation | 2014 | UK-OFGEM | £3,500,001 |
| In Touch Games Limited | | | gambling industry violation | 2021 | UK-GC | £3,400,000 |
| Mitsui Sumitomo Insurance Company (Europe) Ltd | | | insurance violation | 2012 | UK-FSA | £3,345,000 |
| Done Bros (Cash Betting) Limited | | | gambling industry violation | 2023 | UK-GC | £3,250,000 |
| Camelot UK Ltd | Allwyn AG | entertainment | gambling industry violation | 2022 | UK-GC | £3,150,000 |
| E.ON | E.ON | utilities and power generation | consumer protection violation | 2016 | UK-OFGEM | £3,100,000 |
| Mr Green Limited | 888 Holdings PLC | entertainment | gambling industry violation | 2020 | UK-GC | £3,010,349 |
| EDF Energy | EDF-Electricite de France | utilities and power generation | consumer protection violation | 2014 | UK-OFGEM | £3,000,001 |
| E.ON Energy Solutions Limited | E.ON | utilities and power generation | consumer protection violation | 2013 | UK-OFGEM | £3,000,000 |
| Network Rail | Network Rail | miscellaneous services | consumer protection violation | 2010 | UK-ORR | £3,000,000 |
| Camelot UK Lotteries Ltd | Allwyn AG | entertainment | gambling industry violation | 2016 | UK-GC | £3,000,000 |
| William Hill Organization Limited | 888 Holdings PLC | entertainment | gambling industry violation | 2023 | UK-GC | £3,000,000 |
| Platinum Gaming Limited | | | gambling industry violation | 2023 | UK-GC | £2,937,599 |
| Petfre (Gibraltar) Ltd | | | gambling industry violation | 2022 | UK-GC | £2,873,750 |
| Policy Administration Services Limited | | | insurance violation | 2013 | UK-FCA | £2,834,700 |
| OVO Energy | OVO Energy | utilities and power generation | consumer protection violation | 2021 | UK-OFGEM | £2,801,232 |
| Combined Insurance Company of America | Chubb Limited | financial services | insurance violation | 2011 | UK-FSA | £2,800,000 |
| Royal Bank of Scotland Plc and National Westminster Bank Plc | NatWest Group PLC | financial services | consumer protection violation | 2011 | UK-FSA | £2,800,000 |
| Boylesports Enterprise dba Boylesports.com | | | gambling industry violation | 2020 | UK-GC | £2,800,000 |
| Moneybarn Ltd | Vanquis Banking Group | financial services | consumer protection violation | 2020 | UK-FCA | £2,774,400 |
| EE Limited | BT | telecommunications | consumer protection violation | 2017 | UK-OFCOM | £2,700,000 |
| British Gas Trading Limited | Centrica | utilities and power generation | consumer protection violation | 2018 | UK-OFGEM | £2,650,000 |
| Towergate Underwriting Group Limited | | | insurance violation | 2016 | UK-FCA | £2,632,000 |
| British Gas Trading Limited | Centrica | utilities and power generation | consumer protection violation | 2012 | UK-OFGEM | £2,500,000 |
| Gala Interactive (Gibraltar) Limited | Entain PLC | entertainment | gambling industry violation | 2017 | UK-GC | £2,470,309 |
| CT Capital Ltd | | | consumer protection violation | 2016 | UK-FCA | £2,360,900 |
| SSE | SSE PLC | utilities and power generation | consumer protection violation | 2014 | UK-OFGEM | £2,300,000 |
| Zurich Insurance Plc | Zurich Insurance | financial services | privacy violation | 2010 | UK-FSA | £2,275,000 |
| In Touch Games Limited | | | gambling industry violation | 2019 | UK-GC | £2,214,565 |
| Paddy Power Betfair | Flutter Entertainment PLC | entertainment | gambling industry violation | 2018 | UK-GC | £2,200,000 |
| UK Insurance Limited | Direct Line Insurance Group PLC | financial services | insurance violation | 2012 | UK-FSA | £2,170,000 |
