| Christina Nail Spa Ltd | | | tax violations | 2021 | UK-HMRC | £143,372 |
| Christopher Thomas & Co Ltd EAB | | | anti-money-laundering deficiencies | 2023 | UK-HMRC | £14,500 |
| CIE Europe Ltd | | | anti-money-laundering deficiencies | 2020 | UK-HMRC | £1,600 |
| CIM Technologies Ltd. dba Tooth Fairy Finance | | | payday lending violation | 2010 | UK-OFT | £0 |
| Cinderhall Limited | | | accounting fraud or deficiencies | 2024 | UK-ICAEW | £5,458 |
| Circa Accountants Limited ASP | | | anti-money-laundering deficiencies | 2022 | UK-HMRC | £6,072 |
| Circle Contemporary AMP | | | anti-money-laundering deficiencies | 2023 | UK-HMRC | £1,500 |
| Citadel Insurance Company Limited | | | anti-money-laundering deficiencies | 2020 | UK-IOM | £2,170 |
| Citified Management Services Limited | | | tax violations | 2017 | UK-HMRC | £152,480 |
| Citigroup Global Markets Limited | Citigroup | financial services | internal controls deficiency | 2024 | UK-FCA | £27,766,200 |
| Citigroup Global Markets Limited | Citigroup | financial services | internal controls deficiency | 2024 | UK-PRA | £33,880,000 |
| Citigroup Global Markets Limited | Citigroup | financial services | investor protection violation | 2022 | UK-FCA | £12,553,800 |
| Citigroup Global Markets Limited, Citibank N.A. London branch and Citibank Europe Plc UK branch | Citigroup | financial services | internal controls deficiency | 2019 | UK-PRA | £43,890,000 |
| City Fox Investments Limited | | | tax violations | 2024 | UK-HMRC | £124,955 |
| City Heights Legal Solutions Limited | | | anti-money-laundering deficiencies | 2024 | UK-SRA | £2,987 |
| City Index Limited | | | investor protection violation | 2011 | UK-FSA | £490,000 |
| City Move Property Group Limited EAB | | | anti-money-laundering deficiencies | 2023 | UK-HMRC | £4,500 |
| City View Hotel Ltd | | | tax violations | 2018 | UK-HMRC | £12,384 |
| City Wharf Apartments Ltd | | | tax violations | 2018 | UK-HMRC | £27,204 |
| Cityzen Property London Limited EAB | | | anti-money-laundering deficiencies | 2022 | UK-HMRC | £6,600 |
| Cityzen Property Management Limited EAB | | | anti-money-laundering deficiencies | 2022 | UK-HMRC | £7,000 |
| CJ Decorators Ltd | | | tax violations | 2018 | UK-HMRC | £44,064 |
| Clancy's | | | tax violations | 2022 | UK-HMRC | £17,731 |
| Claremont Homes (UK) Limited | | | tax violations | 2019 | UK-HMRC | £146,418 |
| Claremont's Fine & Country Limited EAB | | | anti-money-laundering deficiencies | 2023 | UK-HMRC | £7,400 |
| Clark & Co Estates Ltd EAB | | | anti-money-laundering deficiencies | 2023 | UK-HMRC | £7,000 |
| Clark Mobility Services and Nessies Discount Furniture Store | | | tax violations | 2017 | UK-HMRC | £50,873 |
| Clarke Cole Accounting Limited ASP | | | anti-money-laundering deficiencies | 2022 | UK-HMRC | £4,419 |
| Clarke Demolition Company Limited | | | tax violations | 2021 | UK-HMRC | £78,162 |
| Clarke Nicklin LLP | | | accounting fraud or deficiencies | 2023 | UK-ICAEW | £28,000 |
| Clays Farm Gold Centre | | | tax violations | 2015 | UK-HMRC | £46,781 |
| Clear Junction Ltd | | | economic sanction violation | 2021 | UK-OFSI | £36,393 |
| Clear Vision Accountancy Ltd | | | accounting fraud or deficiencies | 2016 | UK-ICAEW | £10,305 |
| Clearwater Properties | | | tax violations | 2017 | UK-HMRC | £35,259 |
| Clement Hughes & Co | | | anti-money-laundering deficiencies | 2024 | UK-SRA | £9,993 |
| Clicklettings Limited EAB | | | anti-money-laundering deficiencies | 2022 | UK-HMRC | £14,500 |
| Clifford Lax 1919 Limited EAB | | | anti-money-laundering deficiencies | 2023 | UK-HMRC | £4,400 |
| Clive Owen LLP | | | accounting fraud or deficiencies | 2021 | UK-ICAEW | £32,060 |
| Clive Owen LLP | | | accounting fraud or deficiencies | 2022 | UK-ICAEW | £23,048 |
| Close Investments Limited | Close Brothers Group PLC | financial services | investor protection violation | 2010 | UK-FSA | £98,000 |
| Cloud Counting Ltd ASP | | | anti-money-laundering deficiencies | 2023 | UK-HMRC | £1,550 |
| Cloud Genie Ltd | | | accounting fraud or deficiencies | 2018 | UK-ICAEW | £5,068 |
| Club Spice | | | tax violations | 2023 | UK-HMRC | £22,103 |
| Clyde & Co LLP | | | anti-money-laundering deficiencies | 2024 | UK-SDT | £628,197 |
| Clydesdale Bank plc | Nationwide Building Society | financial services | banking violation | 2021 | UK-CMA | £0 |
| CMC Estates Ltd EAB | | | anti-money-laundering deficiencies | 2023 | UK-HMRC | £7,000 |
| CMHDMX | | | tax violations | 2020 | UK-HMRC | £29,939 |
| CMS Metals Ltd | | | tax violations | 2017 | UK-HMRC | £5,774,265 |
| CNEX Ltd. | | | tax violations | 2021 | UK-HMRC | £139,782 |
| CNWC Kennels | | | tax violations | 2020 | UK-HMRC | £17,334 |
| Co Project Ltd | | | tax violations | 2023 | UK-HMRC | £658,008 |
| Co-operative Bank Plc | Co-operative Bank | financial services | internal controls deficiency | 2015 | UK-PRA | £0 |
| Co-Space Consultants Ltd | | | tax violations | 2024 | UK-HMRC | £85,192 |
| Coaching Hotels dba The Griffin Hotel Ltd | | | tax violations | 2017 | UK-HMRC | £16,199 |
| Coady Still Limited | | | tax violations | 2024 | UK-HMRC | £51,608 |
| Coastal Lake | | | tax violations | 2020 | UK-HMRC | £23,156 |
| Cobbin Floyd Limited | | | accounting fraud or deficiencies | 2022 | UK-ICAEW | £2,450 |
| Cobbs Property Services Limited EAB | | | anti-money-laundering deficiencies | 2023 | UK-HMRC | £5,800 |
| Cobham Murphy Limited | | | accounting fraud or deficiencies | 2019 | UK-ICAEW | £5,685 |
| Cocoon Wealth LLP | | | tax violations | 2021 | UK-HMRC | £559,739 |
| Code Hove Ltd dba Barcode Ristorante | | | tax violations | 2020 | UK-HMRC | £63,309 |
| Coey Limited (formerly known as DA Plastering Limited) | | | tax violations | 2024 | UK-HMRC | £29,828 |
| Coffee@The Castle Limited | | | tax violations | 2023 | UK-HMRC | £63,278 |
| Collectors Paradise | | | tax violations | 2018 | UK-HMRC | £9,764 |
| Collier Estates Ltd EAB | | | anti-money-laundering deficiencies | 2023 | UK-HMRC | £1,450 |
| Collins | | | accounting fraud or deficiencies | 2021 | UK-ICAEW | £0 |
| Colour Double Limited | | | anti-money-laundering deficiencies | 2021 | UK-HMRC | £0 |
| Colour My Life Ltd | | | tax violations | 2018 | UK-HMRC | £26,380 |
| Combined Utilities Ltd | | | tax violations | 2017 | UK-HMRC | £23,038 |
| Comform Solutions Ltd | | | anti-money-laundering deficiencies | 2020 | UK-HMRC | £1,000 |
| Comfort Properties Limited EAB | | | anti-money-laundering deficiencies | 2022 | UK-HMRC | £3,700 |
| Comfort Properties Ltd EAB | | | anti-money-laundering deficiencies | 2023 | UK-HMRC | £3,700 |
| Comlights UK Ltd | | | tax violations | 2020 | UK-HMRC | £33,722 |
| Commerzbank AG | Commerzbank | financial services | anti-money-laundering deficiencies | 2020 | UK-FCA | £37,805,400 |
| Commerzbank AG | Commerzbank | financial services | investor protection violation | 2010 | UK-FSA | £595,000 |
| Communion Solutions Ltd Orchid Restaurant | | | tax violations | 2017 | UK-HMRC | £29,489 |
| Company Address Services Ltd | | | anti-money-laundering deficiencies | 2020 | UK-HMRC | £2,500 |
| Company Advice Ltd | | | anti-money-laundering deficiencies | 2020 | UK-HMRC | £9,000 |
| Complete Audit and Accounting Solutions Ltd | | | accounting fraud or deficiencies | 2020 | UK-ICAEW | £3,500 |
| Complete Building Supply Services Ltd | | | tax violations | 2021 | UK-HMRC | £438,134 |
| Complete Construction (GB) Ltd | | | tax violations | 2024 | UK-HMRC | £26,976 |
| Complete Property Maintenance Ltd | | | tax violations | 2017 | UK-HMRC | £92,267 |
| Complex Staging Solutions Ltd dba CGS | | | tax violations | 2017 | UK-HMRC | £59,156 |
| Compliant Pay Ltd | | | tax violations | 2024 | UK-HMRC | £111,735 |
| Computer Giantz Limited | | | tax violations | 2024 | UK-HMRC | £16,609 |
| Computer Matrix Ltd | | | tax violations | 2023 | UK-HMRC | £37,940 |
| Concept Estate Agents Ltd EAB | | | anti-money-laundering deficiencies | 2023 | UK-HMRC | £6,000 |
| Connelly & Co Limited | | | anti-money-laundering deficiencies | 2020 | UK-ICAEW | £700 |
| Connexus Restaurant Limited (Trading as 'Shimla Pinks') | | | tax violations | 2023 | UK-HMRC | £49,221 |
| Connolly Contractors Limited | | | tax violations | 2016 | UK-HMRC | £13,957 |
| Connolly Jones Audit LLP | | | accounting fraud or deficiencies | 2019 | UK-ICAEW | £1,000 |
| Construct Caledonia Limited | | | tax violations | 2024 | UK-HMRC | £50,553 |
| Construct Corp Ltd | | | tax violations | 2018 | UK-HMRC | £103,742 |
| Construction Sealants Ltd | | | tax violations | 2017 | UK-HMRC | £26,804 |
| Consult Frank Ltd | | | tax violations | 2024 | UK-HMRC | £36,440 |
| Consulting Europe Limited | | | tax violations | 2022 | UK-HMRC | £262,261 |
| Contractors 4 U Limited | | | tax violations | 2016 | UK-HMRC | £16,090 |
| Cookson Contracts Limited | | | tax violations | 2016 | UK-HMRC | £30,850 |
| Coombe Gallery Dartmouth AMP | | | anti-money-laundering deficiencies | 2023 | UK-HMRC | £1,250 |
| Cooper Faure Ltd TCSP | | | anti-money-laundering deficiencies | 2023 | UK-HMRC | £14,500 |
| Copeland Residential Sales Limited EAB | | | anti-money-laundering deficiencies | 2022 | UK-HMRC | £7,000 |
