In November 2025, the Supreme Court once again ruled on the IRPH, one of the most controversial mortgage indices in recent years. It did so through two plenary judgments (STS 1590/2025 and STS 1591/2025, both dated November 11), which are the first to apply the doctrine of the Court of Justice of the European Union (CJEU) following its rulings of July 13, 2023 (case C-265/22) and December 12, 2024 (case C-300/23).
The Supreme Court's essential message can be summarized as follows: The IRPH is not declared null and void in general.However, the door to claims is not closed either. From now on, each case must be analyzed individually, following fairly specific parameters regarding transparency and unfairness.
In this post we explain, in the clearest language possible, what the Supreme Court has decided and what practical implications this has for those who have or have had a mortgage referenced to the IRPH.
1. Quick reminder: what is IRPH and why is it being discussed
The IRPH (Mortgage Loan Reference Index) is an official index calculated from the average interest rates applied by lenders to their mortgages. For years, in practice, it has been more expensive than the Euribor, leading many consumers to file lawsuits seeking the annulment of the clause that incorporates it due to a lack of transparency and its unfair nature.
The CJEU, in several judgments, has required that the consumer be able to reasonably understand the operation and economic consequences of the index, but has left room for national courts to specify how that control should be carried out.
The Supreme Court rulings of November 2025 are Spain's response to that European mandate.
2. What the Supreme Court establishes: no automatic solutions
The Plenary Session of the First Chamber starts from a key idea: There is no single solution regarding the IRPHIt cannot be said that all IRPH clauses are automatically null and void, nor that they are always valid. It will depend on:
How the loan was originally arranged.
What information was provided to the consumer?
What specific economic conditions were agreed upon and how do they compare with the market at the time?
To organize this analysis, the Supreme Court separates two levels:
Transparency control (STS 1590/2025): Was the consumer able to understand what the IRPH was and what it meant in economic and legal terms?
Abuse control (STS 1591/2025): If there is a lack of transparency, does that clause create a significant imbalance contrary to good faith?
Only if the clause fails the first check does it enter the second check.
3. STS 1590/2025: the new transparency “test” of the IRPH
In ruling STS 1590/2025, the Supreme Court resolved a 2007 loan referenced to the IRPH Entidades (with IRPH Cajas as a substitute) plus a spread. In that specific case, it concluded that the clause was indeed transparent and ruled in favor of the bank.
What's important for the future isn't so much the outcome of the case as the criteria it sets for assessing transparency:
First we need to see which regulations were applicable Regarding the loan: whether it falls under the Order of May 5, 1994, and the Bank of Spain circulars, or whether it is governed solely by the general regulations on terms and conditions and consumer protection. The pre-contractual information obligations will depend on this.
In loans subject to the 1994 Order, the following takes on special relevance: delivery of the information leaflet and the binding offer, as well as the mentions of the so-called “negative differential” of the IRPH in Circular 5/1994. However, the Supreme Court clarifies that the absence of an express reference to that differential may not be decisive if the client has other clear references to the APR and the Bank of Spain's circular.
The Court considers, in general terms, that access to the content and evolution of the index remains guaranteed by its official publication in the BOE and on the Bank of Spain's websiteThe entity is not required to provide the client with a history of the IRPH, provided that the client is told where they can consult it.
Ultimately, transparency focuses on ensuring the clause is clearly worded and that the consumer has a genuine opportunity to understand the nature of the index and compare it with other offers (for example, loans indexed to the Euribor). The customer is not required to understand all the technical details of the IRPH calculation.
In the case analyzed, the Supreme Court finds that there was pre-contractual documentation, that the clause was extensive and clear, and that borrowers could compare it with other mortgages; therefore, it declares the transparency control to have been met and does not even assess the abusiveness.
4. STS 1591/2025: when can an IRPH clause be abusive
Supreme Court ruling 1591/2025 analyzes another loan, from 2008, in which the clause had already been declared opaque. This lack of transparency does not automatically invalidate it, but it allows for an examination of the clause's content and a question of whether it is abusive.
Here the Supreme Court marks a a rather demanding method to appreciate the abuse:
The trial must take place. with reference to the time of hiring, not looking at the evolution of the IRPH against the Euribor in retrospect over the years.
We need to compare the effective rate resulting from applying the IRPH plus the agreed spread with the average market rates for similar mortgages (amount and term), using objective data from the Bank of Spain and the INE.
It is not correct to simply compare “IRPH + X” with “Euribor + X”, because that “X” differential never existed in a real alternative offer; what matters is to see what was being offered in the market at that time.
Commissions and other costs must also be taken into account to avoid double remuneration, but the fact that the IRPH is calculated from the APR does not make the clause abusive in itself.
The disproportion must be very obvious in order to be able to talk about abusive imbalance, precisely to prevent the courts from ending up carrying out a covert “price control”.
Applying these criteria to the 2008 data (IRPH, Euribor, average mortgage rates from banks and savings banks, synthetic rate, etc.), the Supreme Court concludes that in that specific case There was no significant imbalance and therefore the clause was not abusive.
5. So… is the IRPH legal battle over?
No, but the scenario changes significantly.
The judgments of November 11, 2025 They close the door to automatic and generalized nullity of all IRPH clauses, and raise the bar for proof for the consumer. The key from now on will be to prove, case by case:
That relevant information was lacking in the pre-signature phase (for example, total absence of a brochure, binding offer or minimal explanation about the index and its publication).
That the specific wording of the clause was obscure or confusing to the point of preventing the consumer from understanding that a different and potentially more expensive index than the Euribor was being used.
That the effective rate resulting from that clause deviated very clearly from the average market rates on the date of contracting, also taking into account commissions and expenses.
In other words: Claims are still possible, but they will be more technical and more dependent on documentary and expert evidence..
6. What do we recommend if your mortgage is linked to the IRPH?
If your mortgage loan is or has been linked to the IRPH, these are, in general, the reasonable actions you can take:
Review in detail the loan agreement and all pre-contractual documentation that you keep (binding offer, simulations, brochures, emails from the bank…).
Locate the exact date of concession of the loan, because it determines the applicable regulations and the information duties that the entity had.
Analyze how the product was presented to you: whether you were offered alternatives referenced to the Euribor, whether it was explained to you that the IRPH usually stood above other indices, whether you were told where you could check its evolution.
Perform a comparative study of types On the date of contracting, using official data from the Bank of Spain and the INE, to see if the effective rate you were paying was clearly above the market rate.
With that documentary basis, a lawyer specializing in banking and consumer law can realistically assess the chances of success, both from the perspective of transparency and abusiveness.
7. How we handle these types of matters at the firm
In our office we analyze these types of mortgages case by case, following the same logic established by the Supreme Court:
Study of writing and pre-contractual documentation.
Determination of the applicable regulatory framework on the date of contracting.
Reconstruction of the evolution of your loan and comparison with average market rates.
Legal assessment of the possible lack of transparency and, where applicable, the existence (or not) of an abusive imbalance.
Proposed strategy: out-of-court negotiation with the entity or, if appropriate, legal claim.
If you have or have had a mortgage linked to the IRPH and want to know how these new Supreme Court rulings affect you, we can review your case individually and explain, with numbers and with the law, what real options you have.