United Kingdom
- Complaint to the bank — Immediately, in writing. The bank must give a final response within 8 weeks, and within 15 business days (35 in exceptional cases) for payment services and e-money. Open to any client. primary source
- Financial Ombudsman Service — After the final response or once the bank's deadline passes, within 6 months of the response. Free; the client or a representative files, and the decision binds the bank. Takes consumers, micro-enterprises, small businesses, smaller charities and trusts. primary source
- Data subject access request — In parallel. Under UK GDPR the bank usually answers within a month; often the only way to learn the real grounds. A natural person's right; a company has none. primary source
Deadlines: On open-ended contracts entered into from 28 April 2026 the bank gives 90 days' notice of closure with detailed reasons; earlier contracts keep 2 months. Exceptions: customer due diligence that cannot be completed, reasonable suspicion of serious crime, a regulator's requirement. Final response to a complaint: 8 weeks; 15 business days for payment services and e-money. Ombudsman filing: within 6 months of the response, and no later than 6 years from the event or 3 years from becoming aware of it.