The freezing or blocking of a bank account by a financial institution is a security measure that may affect both individuals and companies. Although it is less common today due to the intensification of regulatory compliance controls, this action cannot be carried out arbitrarily and must comply with a strict legal framework.
In this article, we break down what may happen, what you can do, and how to protect yourself from a legal perspective.
Why can a bank block your account on suspicion of fraud?
Financial institutions are required to monitor their customers’ accounts in compliance with Law 10/2010 on the Prevention of Money Laundering and Terrorist Financing and various European due diligence directives. This allows — and even obliges — them to take action when they detect signs of unusual or fraudulent activity.
1. Lack of documentation or updated identification
Banks must keep up-to-date information about the account holder and verify their identity and economic profile in accordance with anti-money laundering regulations. If the customer fails to respond to requests within the specified timeframe, the bank may proceed to block access.
2. Suspicious transactions or fraud alerts
Transactions that do not match the customer’s profile, unusual transfers, or movements that may suggest money laundering or fraud can trigger automated systems that lead the bank to temporarily suspend the account while it investigates.
3. Judicial or administrative order
In certain cases, tax or judicial authorities may directly request the freezing of an account as part of a criminal or tax investigation. In these situations, the blocking is not decided independently by the bank but is carried out pursuant to a legal mandate.
Account holder’s rights and the bank’s obligations when an account is blocked
Once the measure has been adopted, the institution must comply with certain information and transparency obligations, except in exceptional cases related to confidentiality or anti-money laundering requirements:
Inform you of the reason for the blocking, unless there are legal grounds preventing disclosure.
Explain what documentation or actions you must provide to unblock the account.
Maintain active communication through registered channels (email, app notifications, messages) to inform you of the situation and estimated timeframes.
These obligations are set out in banking regulations and in the Bank of Spain’s guidelines on best practices.
Although the bank has the authority to block an account, you are not legally unprotected. Your rights include:
The right to be informed of the reasons and the unblocking process.
The right to provide evidence or documentation justifying your transactions.
The right to file a complaint if you believe the blocking is unjustified, disproportionate, or unduly prolonged.
The right to submit complaints to the institution’s Customer Service Department and, if you do not receive a satisfactory response, to the Bank of Spain.
The right to claim compensation for damages if an improper blocking causes demonstrable financial harm.
Example: if the bank fails to provide adequate information or maintains the blocking without justification, you may be entitled to seek compensation.
Legal framework and relevant case law
Law 10/2010 on the Prevention of Money Laundering: requires banks to monitor transactions when there are indications of suspicious activity.
Royal Decree-Law 19/2018 (Payment Services Act): strengthens users’ rights in relation to unauthorized transactions and the liability of financial institutions.
Supreme Court Judgment 571/2025: establishes that, except in cases of gross negligence by the customer, banks must reimburse amounts lost due to digital fraud (phishing, smishing, etc.) and act with due diligence.
These rules and judicial criteria create a legal environment in which financial institutions’ obligations are demanding and customers’ rights have been reinforced, particularly in the digital sphere.
What to do if your account is blocked
If your account is blocked due to suspected fraud, follow these steps:
Contact your bank immediately through official channels and request detailed explanations.
Gather all relevant documentation (contracts, statements, communications, screenshots).
Provide any evidence that justifies the legitimacy of the transactions or clarifies the situation.
Submit a formal written complaint to the bank if the response is unsatisfactory.
If there is no solution, escalate your complaint to the Bank of Spain through its Complaints Service.
Consider seeking specialized legal advice if there are significant financial damages or the situation becomes more complex.
Keeping a detailed record of all communications — including emails, calls, and responses — is essential for any subsequent complaint or legal action.
Prevention and response: how to reduce the risk of fraud and unexpected account blocking
Although a blocking may be legally justified, in many cases avoiding or reducing risks depends on you:
Keep your documentation and identification details up to date.
Activate all security measures offered by your bank (two-factor authentication, instant notifications, etc.).
Regularly review your account activity and report any irregularities immediately.
Do not share your passwords with anyone or click on suspicious links received by SMS or email (smishing and phishing fraud are on the rise).
Consult the Bank of Spain’s resources on fraud prevention.
In conclusion, a temporary account freeze due to suspected fraud may be legally justified, but so are your rights as a customer. Understanding the legal framework, knowing what to demand, and how to respond will give you control over the situation and help minimize unnecessary risks and costs.
If you need more personalized guidance or legal assistance, it is always advisable to consult a lawyer specialized in banking law. We can assist you whenever you need legal support. Contact our team here!