Unfair contract terms (cláusulas abusivas) and small print

Key rules

• Burden of proof: If a business claims a clause was negotiated, it must prove it.
• Effect: A void clause is treated as never included, and the rest of the contract normally continues.
• Refund: You can claim back amounts paid under a void clause, with legal interest.
• Before court: Try an out-of-court settlement first, because most civil claims now require it.

An unfair clause is void, and the contract usually survives

A clause is void if it was not negotiated with you and it clearly tips the balance against you. It is also void if it is on the list of clauses that are always unfair. A void clause is treated as if it was never in the contract. The rest of the contract normally continues. You can contest the clause with the business, with a consumer office or in court.

How to spot an unfair clause

A clause is unfair when it meets all three tests:

• Not negotiated. You could not influence its content. This is typical of standard-form or pre-drafted contracts, where you sign what you are given.
• Against good faith. It is not a fair deal between the two sides.
• Significant imbalance. Your rights and duties are worse than the business's, to your detriment.

If the business says you negotiated a clause, it has to prove it. You do not have to prove the opposite. Fairness is judged as of the day you signed. The judge looks at what you bought, the circumstances and the other clauses in the contract.

Clauses that are always unfair

These types of clause are on the list of always-unfair terms:

• The business controls the contract. Examples are changing terms alone, interpreting the contract alone, or ending it without giving you the same right.
• Limits on your basic rights. Examples are excluding or limiting your remedies, banning set-off, or limiting liability for death or injury.
• No balance between the parties. Examples are heavier penalties for you than for the business, price rises with no right for you to withdraw, or charges for services you did not ask for.
• Guarantee tricks. Examples are reversing the burden of proof against you, or making you liable for things that are not your fault.
• Other bad-faith terms. Examples are unjustified extra charges or penalties, tied sales, waiving your consumer rights, or forcing arbitration other than the official consumer arbitration system.
• Terms on how the contract is made and performed. An example is a one-sided extension of the contract.
• Distant courts. A clause sending disputes to a court other than the one where you live or signed is unfair.

What happens when a clause is declared void

The clause is removed and the contract continues if it can work without it. If it cannot, the whole contract is void. A court can fill gaps and, if the contract would still seriously harm you, adjust the parties' rights and duties. It cannot soften a void penalty clause. The penalty simply disappears.

You can claim back what you paid under a void clause, with legal interest.

How to challenge a clause, step by step

Go in this order:

1. Write to the business's customer service. Ask for the clause to be removed and for a refund. Send it in a way that leaves proof, and keep a copy.
2. Complain to a consumer office. Use your town hall's consumer office (OMIC) or your regional consumer authority. They can mediate and can open a sanction file against the business. For banks and insurers, complain first to the company's own complaints service. If that fails, go to the Bank of Spain or the insurance regulator.
3. Try consumer arbitration. The Junta Arbitral de Consumo is free and voluntary, and its decision is binding. It only works if the business has joined the system.
4. Go to court. You can ask a court to declare the clause void, in the court where you live. Smaller claims use a simplified procedure. Before most civil claims, you now have to try an out-of-court settlement, such as a written claim to the business or mediation. Keep proof of that attempt.

A lawyer and a court representative (procurador) are generally required for claims above 2,000 euros. Court costs usually go to the loser, though in consumer cases they may be limited.

Consumer associations and the Ministry of Consumer Affairs can bring collective actions. For mortgage deeds, a notary or property registrar can refuse to register abusive clauses.

The warnings, decision guide and FAQ below cover the common traps and questions.

Choosing between options

Will the contract continue without the unfair clause, or fall entirely?

• Contract continues without the clause: The contract can work without it. The clause is treated as never included, you get back what you paid under it with legal interest, and the court may fill gaps if the contract harms you significantly.

• Whole contract is void: The contract cannot survive without the clause. A court declares it void as a whole, so you can leave it and claim back what you paid.

If the contract can work without the unfair clause, it continues without it. If it cannot, the whole contract is void. Either way, a court decides after hearing both sides.

What to watch out for

• Signed does not mean binding: A clause that is unbalanced, was not negotiated or is on the blacklist is void, even if you signed. The rest of the contract normally stays in force. Do not pay under a suspicious clause without objecting. Ask the trader in writing to remove it and keep proof of sending.

• Clauses that are always unfair: Some clauses are always unfair: the trader changing terms or price alone with no right for you to leave, penalties that are not equal on both sides, extra charges for services you did not ask for, waiving your rights, forced private arbitration, tied sales, and a court far from your home. Read the small print for these before signing. If you find one, point it out in writing and ask for it to be removed.

• Late or wrong complaint route: Going straight to court can fail if you skipped the required out-of-court attempt. Arbitration only works if the trader has joined the consumer arbitration system. Start with a written claim to the trader's customer service, then your town hall's consumer office (OMIC) or regional consumer authority, and only then court.

• Do not expect a softened penalty: If the whole contract cannot work without the void clause, the entire contract is void. A void penalty clause is not reduced; it simply falls. Ask for a refund of everything paid under the clause, with legal interest.

Frequently asked questions

Who has to prove that a clause was negotiated?

The trader has to prove that a clause was individually negotiated, not you. A clause in a pre-drafted or standard-form contract that you could not influence counts as non-negotiated. Whether it is unfair is judged as of the day you signed, looking at the whole contract.

Can I get my money back if a clause is declared void?

Yes, the trader must refund what you paid under the void clause, plus legal interest. A court cannot soften a void penalty clause to keep part of it. Ask for the refund in your written claim to the trader.

Do I need a lawyer to challenge an unfair clause in court?

A lawyer and a court representative (procurador) are generally required for claims above 2,000 euros. Since 2025, most civil claims also need a prior attempt at out-of-court settlement, such as a claim to the trader or mediation. File the court action in the court of your home.

What if the problem is in a bank or insurance contract?

Complain first to the bank's or insurer's own complaints service. If that fails, take it to the Bank of Spain for banking or the DGSFP, the insurance regulator, for insurance.