Official mortgage rates September 2026: 3.189% and 3.600% — what changes in your payment

Key data

If your variable mortgage is not referenced to Euribor but to one of the official indices of the Bank of Spain, the data published on October 20, 2026 are what will determine your next payment review. The Resolution of October 19, 2026 from the Bank of Spain, published in the BOE in accordance with Circular 5/2012, establishes two specific figures that every holder of this type of mortgage should know.

Although these indices are less common than Euribor, they remain the contractual reference for thousands of mortgages in Spain, especially those formalized before Euribor became generalized as the main index. Ignoring this monthly publication could mean failing to anticipate a change in the monthly payment.

What does this regulation establish?

The Bank of Spain publishes monthly, under Circular 5/2012, the official reference interest rates for the mortgage market. This publication does not set new rates or modify contracts: it collects statistical data from the market corresponding to September 2026 and converts them into official reference indices.

The two indices published in this resolution are:

These indices are not Euribor. They are alternative references that some mortgage contracts—especially older ones—use as a basis for calculating the variable interest rate applicable in each review period. If your mortgage deed mentions any of these indices, this publication affects you directly.

Economic and operational impact

The economic impact of these indices depends directly on what each individual mortgage contract establishes. However, there are key elements that every holder should consider:

• The national average rate of 3.189% is the data that will be applied as the base reference in variable mortgages linked to the index of mortgage loans for more than three years for free housing in Spain, in the next contractual review.
• The average European rate of 3.600% applies to contracts referenced to the European index of housing loans between one and five years.
• The difference between both indices is 0.411 percentage points, which can represent a relevant difference in the monthly payment depending on the outstanding capital.
• To these indices is added the spread agreed in the contract (usually between 0.5 and 1.5 points), so the final rate applied will be higher than the published figures.

From an operational perspective, financial entities use this data to automatically calculate new payments in periodic reviews. The holder does not need to take any action, but should verify that the calculation applied by their bank matches the correct index and the spread agreed in the deed.

Who does it affect?

• Holders of variable mortgages whose contract is referenced to the average rate of mortgage loans for more than three years for free housing in Spain.
• Holders of variable mortgages referenced to the average European rate of housing loans between one and five years.
• Financial and mortgage advisors who manage client portfolios with this type of products.
• Credit entities that must apply these indices in their periodic reviews in accordance with current contracts.
• Real estate investors with variable financing referenced to these official indices.

It is important to note that the majority of variable mortgages in Spain are referenced to Euribor, not to these indices. If you have doubts about which index your mortgage uses, consult the mortgage loan deed or the latest statement sent by your entity.

Practical example

Suppose a holder with a variable mortgage of €150,000 outstanding capital, for 20 years, referenced to the average rate of mortgage loans for more than three years for free housing in Spain, with a spread of +0.75%.

With September 2026 data:

• Official index: 3.189%
• Agreed spread: +0.75%
• Rate applicable in the next review: 3.939%

This rate of 3.939% will be what determines the new monthly payment during the next review period (usually semi-annual or annual, depending on the contract). If the same holder had their mortgage referenced to the European index (3.600% + 0.75% = 4.350%), the resulting payment would be noticeably higher, which illustrates the importance of knowing exactly which index your deed contains.

What should mortgage holders do now?

1. Identify your mortgage's reference index: Review the mortgage loan deed or the latest statement from your entity to confirm whether your mortgage is referenced to the national average rate (3.189%) or the European average rate (3.600%).
2. Calculate your new applicable rate: Add the published official index (3.189% or 3.600%) to the spread agreed in your contract. That will be the rate applied in your next review.
3. Verify your entity's calculation: When you receive the payment review notification, check that the index used matches the one published by the Bank of Spain for September 2026 and that the spread applied is correct according to the deed.
4. Consult with your financial or mortgage advisor if you detect discrepancies between the rate communicated by your bank and the one resulting from applying the official data published.
5. Maintain monthly monitoring: The Bank of Spain publishes these indices every month. If your review is semi-annual or annual, the applicable index will be the one from the month prior to the review date as agreed in your contract.

Official source

Consult complete regulation in official source

Notice: This article is purely informational in nature and does not constitute legal advice. For specific decisions, consult a qualified professional. Source: https://www.boe.es/diario_boe/txt.php?id=BOE-A-2026-21866